Biology Final Exam Flashcards
(587 cards)
1
Q
Spider silk is made of:
A. proteins. B. RNA. C. carbohydrates. D. lipids. E. DNA.
A
A. proteins.
2
Q
Characteristics of carbon that contribute to its ability to form an immense diversity of organic molecules include its
A. ability to bond with up to four other atoms.
B. All of the choices are correct.
C. capacity to form single and double bonds.
D. tendency to form covalent bonds.
E. ability to bond together to form extensive, branched, or unbranched “carbon skeletons.”
A
B. All of the choices are correct.
3
Q
Hydrocarbons
A. are composed of carbon atoms that are attached to hydrogen skeletons.
B. consist of atoms linked exclusively by single bonds.
C. All of the choices are correct.
D. are inorganic compounds.
E. contain only carbon and hydrogen atoms.
A
E. contain only carbon and hydrogen atoms.
4
Q
Propanol and isopropanol are isomers. This means that they have
A. the same molecular formula and the same chemical properties.
B. the same molecular formula but different chemical properties.
C. the same molecular formula, but propanol is the liquid form of the compound and isopropanol is the gaseous form.
D. different molecular formulas but the same chemical properties.
E. the same number of carbon atoms but different numbers of oxygen and hydrogen atoms.
A
B. the same molecular formula but different chemical properties.
5
Q
Organic compounds
A. always contain carbon and are synthesized by cells.
B. can only be synthesized in a laboratory.
C. always contain nitrogen.
D. always contain carbon.
E. are synthesized by cells.
A
A. always contain carbon and are synthesized by cells.
6
Q
You now know that the old “oil and water don’t mix” is true. Why?
A. Oil is an organic compound and water is not.
B. Water is hydrophobic.
C. Oil is hydrophilic.
D. Water exhibits polarity and oil does not.
E. Oil exhibits polarity and water does not.
A
D. Water exhibits polarity and oil does not.
7
Q
A hydroxyl group is
A. also called a carbonyl group. B. hydrophobic. C. None of the choices are correct. D. characteristic of proteins. E. characteristic of alcohols.
A
E. characteristic of alcohols.
8
Q
Which one of the following is an amino group?
- NH2
- OH
- CO
- CH3
- COOH
A
-NH2
9
Q
Which one of the following statements about the functional groups of organic compounds is not true?
A. Functional groups help make organic compounds soluble in water
B. Functional groups participate in chemical reactions
C. All functional groups include a carbon atom of the organic compound’s skeleton
D. Functional groups help make organic compounds hydrophilic
E. Many biological molecules have two or more functional groups
A
C. All functional groups include a carbon atom of the organic compound’s skeleton
10
Q
Which one of the following statements about the monomers and polymers found in living organisms is not true?
A. The monomers used to make polymers are essentially universal
B. Monomers are joined together by the process of hydrolysis
C. Cells typically make all of the macromolecules from a set of 40 to 50 common monomers and a few other ingredients that are rare
D. Monomers serve as building blocks for polymers
E. DNA is built from just four kinds of monomers
A
B. Monomers are joined together by the process of hydrolysis
11
Q
Monosaccharides can be joined together by a process called dehydration synthesis. Which of the following statements is true of this process?
A. H2O is formed as the monomers are joined
B. Electrons are shared between atoms of the joined monomers
C. One monomer loses a hydrogen atom and the other loses a hydroxyl group
D. Covalent bonds are formed between the monomers
E. All of the choices are correct
A
E. All of the choices are correct
12
Q
The results of dehydration synthesis can be reversed by
A. a hydrolysis reaction and digestion. B. a condensation reaction. C. digestion. D. polymerization. E. a hydrolysis reaction.
A
A. a hydrolysis reaction and digestion.
13
Q
Which list below consists of only polymers?
A. proteins, lipids, nucleic acids, polysaccharides
B. sugars, amino acids, nucleic acids, lipids
C. polysaccharides, lipids, amino acids, nucleic acids
D. proteins, lipids, nucleotides, sugars
E. proteins, lipids, nucleic acids, amino acids
A
A. proteins, lipids, nucleic acids, polysaccharides
14
Q
The molecular formula of most monosaccharides represents a multiple of
A. CH2O B. CHO. C. CHO3. D. CHO2. E. CH3O
A
A. CH2O
15
Q
A molecule with the formula C55 H110 O55 is probably a(n)
A. steroid. B. oil. C. polysaccharide. D. protein. E. wax.
A
C. polysaccharide.
16
Q
Sucrose is formed
A. when water molecules are added to two monosaccharides.
B. from two glucose molecules.
C. when ionic bonds link two monosaccharides.
D. when glucose and lactose are combined.
E. from two monosaccharides by dehydration synthesis.
A
E. from two monosaccharides by dehydration synthesis.
17
Q
A disaccharide forms when
A. two starches join by dehydration synthesis.
B. a starch and a monosaccharide join by dehydration synthesis.
C. two starches join by hydrolysis.
D. two monosaccharides join by hydrolysis.
E. two monosaccharides join by dehydration synthesis.
A
E. two monosaccharides join by dehydration synthesis
18
Q
Molecules that taste sweet
A. must bind to the sweet and bitter receptors.
B. have a shape that binds tightly to sweet taste receptors.
C. cause carbohydrates to break down into monomers that trigger the sweet taste reaction.
D. include at least one carbohydrate monomer.
E. are all carbohydrates.
A
B. have a shape that binds tightly to sweet taste receptors.
19
Q
Which one of the following lists contains only polysaccharides?
A. fructose, cellulose, and glucose B. nucleotides, glycogen, and cellulose C. cellulose, starch, and glycogen D. sucrose, starch, and cellulose E. starch, amino acids, and glycogen
A
C. cellulose, starch, and glycogen
20
Q
Cellulose differs from starch in that
A. starch is made of glucose monomers, whereas cellulose is made of fructose monomers.
B. glycogen is formed by plants and cellulose by animals.
C. All of the choices are correct.
D. most animals cannot break down cellulose, whereas starch is easily digested.
E. the monomers of cellulose are held together by covalent bonds, whereas the monomers of starch are held together by hydrogen bonds.
A
D. most animals cannot break down cellulose, whereas starch is easily digested.
21
Q
Foods that are high in fiber are most likely derived from
A. meat. B. any of these choices. C. plants. D. dairy products. E. fish.
A
C. plants
22
Q
Cows can derive nutrients from cellulose because
A. they chew their food so thoroughly that cellulose fibers are broken down.
B. they produce the enzymes that break down cellulose.
C. their intestinal tract contains termites, which can break down cellulose.
D. they convert cellulose into starch, which is easily broken down in the intestinal tract.
E. their intestinal tract contains cellulose-hydrolyzing microorganisms.
A
E. their intestinal tract contains cellulose-hydrolyzing microorganisms.
23
Q
The storage form of carbohydrates in animals is __________ and in plants is __________.
A. cellulose . . . glycogen B. glycogen . . . starch C. sucrose . . . glycogen D. glycogen . . . cellulose E. starch . . . glycogen
A
B. glycogen . . . starch
24
Q
One way to convert an oil into a substance that is solid at room temperature is to
A. add hydrogens, decreasing the number of double bonds in the molecules.
B. put it in the refrigerator: when unsaturated fats cool, double bonds form and the fats solidify.
C. remove water, causing a dehydration synthesis reaction to occur.
D. add water and shake vigorously.
E. remove hydrogens, increasing the number of double bonds.
A
A. add hydrogens, decreasing the number of double bonds in the molecules
25
Which one of the following is not true about animal cell lipids?
A. Phospholipids are important components of cell membranes
B. Many lipids function as enzymes
C. Fats are a form of lipid that functions as energy containing molecules
D. Cholesterol is a type of lipid used in cell membranes and as a starting material for making steroid hormones
E. Steroids are lipids that function as signaling molecules
B. Many lipids function as enzymes
26
A diet high in animal products may increase the risk for atherosclerosis. This is because
A. most animal fats are used for energy storage and most animal products contain high levels of unsaturated fats.
B. most animal fats are saturated and most animal products contain high levels of triglycerides.
C. most animal fats are hydrogenated oils and most animal products contain high levels of phospholipids.
D. most animal products contain high levels of unsaturated oils and anabolic steroids.
E. most animal fats are unsaturated and most animal products contain high levels of steroids.
B. most animal fats are saturated and most animal products contain high levels of triglycerides.
27
In salad dressings, oil quickly separates from vinegar because oils are
```
A. amphiphilic.
B. heavier than water.
C. polar.
D. hydrophilic.
E. non-polar.
```
E. non-polar.
28
Suppose you wanted to make margarine using a plant oil. How would you alter the oil molecules to make the oil solid at room temperature?
A. use a larger glycerol
B. attach more fatty acids to each glycerol
C. add hydrogens to change the double bonds in the fatty acids to single bonds
D. reduce the number of fatty acids attached to each glycerol
E. add a phosphate group to the glycerol
C. add hydrogens to change the double bonds in the fatty acids to single bonds
29
Because water and oil don't mix, water is not very effective at washing away dirt. The ability of soap to mix with both water and oily dirt allows dirt to be washed away. Which statement provides the most logical chemical explanation for this phenomenon?
A. Soap molecules carry no charge. As a result soap can form an effective bridge between charged water molecules and neutral oil molecules
B. Soap molecules have both positively and negatively charged regions. The negatively charged regions are attracted to water; the positively charged regions are attracted to oil.
C. Soap molecules have charged regions and neutral regions; the charged regions are attracted to water molecules; the neutral regions are attracted to oils.
D. Soap molecules have charged regions and neutral regions. The neutral regions are attracted to water molecules. The charged regions are attracted to oils.
E. Soap molecules have both positively and negatively charged regions. The positively charged regions are attracted to water. The negatively charged regions are attracted to oil.
C. Soap molecules have charged regions and neutral regions; the charged regions are attracted to water molecules; the neutral regions are attracted to oils.
30
A triglyceride:
A. Plays a role in energy storage
B. Is a type of fat
C. Is hydrophobic
D. Consists of three fatty acids attached to a glycerol
E. All of the choices are correct
E. All of the choices are correct
31
Fatty acids with double bonds between some of their carbons are said to be
```
A. monoglycerides.
B. triglycerides.
C. saturated.
D. unsaturated.
E. completely hydrogenated.
```
D. unsaturated.
32
If you want to promote the development of atherosclerotic disease, you would eat a diet high in
```
A. fiber.
B. saturated fats.
C. complex carbohydrates.
D. sugars.
E. protein.
```
B. saturated fats
33
If you were to add olive oil to your food as part of a diet to lower your risk of atherosclerotic disease, you would use olive oil that
```
A. was hydrogenated.
B. had lard added to it.
C. was liquid at room temperature.
D. None of the choices are correct.
E. was modified to be solid at room temperature.
```
C. was liquid at room temperature.
34
A phospholipid is composed of
A. one glycerol molecule linked to three fatty acid molecules.
B. one glycerol molecule linked to one phosphate group and two fatty acid molecules.
C. one fatty acid molecule linked to three glycerol molecules.
D. one fatty acid molecule linked to one glycerol molecule and two phosphate groups.
E. one glycerol molecule linked to three phosphate groups.
B. one glycerol molecule linked to one phosphate group and two fatty acid molecules
35
Which one of the following substances is not a lipid
```
A. Cellulose
B. Steroids
C. Triglycerides
D. Wax
E. Cholesterol
```
A. Cellulose
36
A major type of lipid found in cell membranes is
```
A. phospholipids.
B. waxes.
C. triglycerides.
D. glycerol.
E. cellulose.
```
A. phospholipids
37
Which one of the following statements is not true about waxes? Waxes are
A. used as a starting material for making steroids.
B. non-polar.
C. used by some insects and plants for protection.
D. lipids.
E. more hydrophobic than fats.
A. used as a starting material for making steroids.
38
Which one of the following statements about anabolic steroids is not true? Anabolic steroids
A. Chemically resemble testosterone
B. Promote bone growth
C. Can stimulate mood swings and violent behavior
D. Cause a general buildup of muscle mass
E. Often causes the body to reduce its normal output of sex hormones
B. Promote bone growth
39
Which one of the following statements about androstenedione is not true?
A. Androstenedione is normally produced in the body and converted to testosterone
B. Taking androstenedione decreases levels of good cholesterol
C. Taking androstenedione can increase the likelihood of cardiovascular disease, cancer, and breast enlargement in males
D. Studies show that taking androstenedione greatly increases the production of male sex hormones
E. Taking androstenedione can lead to premature puberty and stunted growth
D. Studies show that taking androstenedione greatly increases the production of male sex hormones
40
A scientist suspects that the food in an ecosystem may have been contaminated with radioactive nitrogen over a period of months. Which of the following substances could be examined for radioactivity to test the hypothesis?
A. Any of these choices.
B. the cell walls of plants growing in the ecosystem
C. the sugars produced during photosynthesis by plants growing in the ecosystem
D. the hair produced by humans living in the ecosystem
E. the cholesterol in the cell membranes of organisms living in the ecosystem
D. the hair produced by humans living in the ecosystem
41
Which one of the following statements is not true? Enzymes
A. Have structures that correspond to their function
B. Function as organic catalyst
C. Are typically consumed by the reactions they promote
D. Regulate virtually all chemical reactions in a cell
E. Are proteins that change the rate of chemical reactions
C. Are typically consumed by the reactions they promote
42
Proteins differ from one another because
A. the sequence of amino acids in the polypeptide chain differs from protein to protein.
B. each protein contains its own unique sequence of sugar molecules.
C. the number of nitrogen atoms in each amino acid varies.
D. the number of nucleotides found in each protein varies from molecule to molecule.
E. the peptide bonds linking amino acids differ from protein to protein.
A. the sequence of amino acids in the polypeptide chain differs from protein to protein.
43
Amino acids can be distinguished from one another by
A. the chemical properties of their R groups.
B. the number of R groups found on the amino acid molecules.
C. All of the choices are correct.
D. the chemical properties of their amino and carboxyl groups.
E. the type of bond between the R group and the rest of the amino acid molecule.
A. the chemical properties of their R groups.
44
Glucose molecules are to starch as __________ are to proteins.
```
A. fatty acids
B. amino acids
C. waxes
D. oils
E. lards
```
B. amino acids
45
Peptide bonds
```
A. None of the choices are correct.
B. link amino acids.
C. are used to form amino acids.
D. are formed by a hydrolysis reaction.
E. form between fatty acids.
```
B. link amino acids.
46
Which one of the following will not be affected by the denaturation of a protein?
A. The number of amino acids in the protein
B. The function of the protein
C. The shape of the protein
D. The solubility of the protein in water
E. The binding properties of the protein
A. The number of amino acids in the protein
47
Which of the following factors can result in the denaturation of a protein?
A. Chemicals that destroy hydrogen bonds
B. Changes in pH
C. Heat
D. Changes in salt concentration
E. All of the choices can result in the denaturation of a protein
E. All of the choices can result in the denaturation of a protein
48
The __________ structure of a protein consists of a chain of amino acids assembled in a specific order.
```
A. tertiary
B. primary
C. quaternary
D. secondary
E. None of the choices are correct
```
B. primary
49
Which one of the following is an example of secondary structure in a protein?
```
A. A globular shape
B. A particular amino acid sequence
C. An alpha helix
D. A fibrous shape
E. The joining of two polypeptide chains
```
C. An alpha helix
50
The tertiary structure of a polypeptide refers to
A. the amino acids of which it is made.
B. the number of R groups it contains.
C. the presence of pleated sheets.
D. the overall three-dimensional structure.
E. its size.
D. the overall three-dimensional structure.
51
A protein containing more than one polypeptide chain exhibits the __________ level of protein structure.
```
A. quaternary
B. secondary
C. infinite
D. primary
E. tertiary
```
A. quaternary
52
Which one of the following statements about Linus Pauling is not true? Linus Pauling
A. is the only person ever to receive two unshared Nobel Prizes.
B. first described the double-helix shape of DNA.
C. determined how hemoglobin carries oxygen.
D. first described the two fundamental secondary structures of proteins.
E. helped to produce a ban on nuclear testing.
B. first described the double-helix shape of DNA.
53
Nucleotides
A. All of the choices are correct.
B. can be linked together to form nucleic acids.
C. contain sugar molecules.
D. contain phosphate groups.
E. contain nitrogenous bases.
A. All of the choices are correct.
54
DNA differs from RNA because DNA
A. All of the choices are correct.
B. consists of a single rather than a double polynucleotide strand.
C. contains pentose rather than hexose sugars.
D. contains phosphate groups.
E. contains thymine in place of uracil.
E. contains thymine in place of uracil.
55
Genetic information is encoded in the
A. length of glycogen.
B. degree of saturation of fatty acids.
C. quaternary structure of a protein.
D. linear sequence of amino acids in a polypeptide.
E. sequence of nucleotides in DNA.
E. sequence of nucleotides in DNA.
56
Which one of the following is not the proper pairing of a polymer and its monomer?
A. nucleic acid and nucleotide
B. triglyceride and steroid
C. All of the pairs properly reflect a polymer and its corresponding monomer.
D. polysaccharide and monosaccharide
E. protein and amino acid
B. triglyceride and steroid
57
A new "wonder food" is being distributed by a rival company. The researchers in your company determine that the "wonder food" contains only carbon, oxygen, and hydrogen. At this point, your researchers can say with certainty that the food
```
A. could only be made of triglycerides.
B. includes proteins.
C. could only be made of carbohydrates.
D. does not include proteins or nucleic acids.
E. includes nucleic acids.
```
D. does not include proteins or nucleic acids.
58
The glucose produced by a plant is used to make the carbohydrate, proteins, fats, and nucleic acids of the plant. Which statement is true about the process of converting sugars into other molecules?
A. Glucose contains all of the elements needed to produce these other molecules.
B. Glucose contains all of the elements needed to produce the carbohydrates and fats, but other elements must come from the soil if the plant is to produce proteins and nucleic acids.
C. Glucose contains all of the elements needed to produce the carbohydrates, but other elements must come from the soil if the plant is to produce fats, proteins, and nucleic acids.
D. None of the substances in the other answers can be produced from glucose alone.
E. Glucose contains all of the elements needed to produce the carbohydrates and nucleic acids, but other elements must come from the soil if the plant is to produce proteins and fats.
B. Glucose contains all of the elements needed to produce the carbohydrates and fats, but other elements must come from the soil if the plant is to produce proteins and nucleic acids.
59
Art is important to biology because
A. most art includes a detailed study of an aspect of biology.
B. great art inspires scientists to work.
C. many biologists were first artists.
D. biologists use art to illuminate their findings.
E. many scientific advances began with the study of art.
D. biologists use art to illuminate their findings.
60
Resolving power is the
A. size of an image.
B. distance between the lenses of a microscope.
C. ability of an optical instrument to magnify an image.
D. ability of an optical instrument to show two objects as separate.
E. ability of an optical instrument to estimate the size of an image.
D. ability of an optical instrument to show two objects as separate.
61
Light microscopes
A. can generally magnify objects about 10,000 times without blurring.
B. work by reflecting electrons off the surface of an object being studied.
C. use light and glass lenses to magnify an image.
D. typically provide more resolution than an electron microscope.
E. All of the choices are correct.
C. use light and glass lenses to magnify an image.
62
Which one of the following statements is true about electron microscopes?
A. Electron microscopes use glass lenses to focus and magnify the image.
B. Electron beams are focused to create a magnified image of an object.
C. Specimens must be sectioned to be viewed under a scanning electron
microscope.
D. Transmission electron microscopes are used to study the architecture of cell surfaces.
E. Scanning electron microscopes are used to study the details of internal cell structure.
B. Electron beams are focused to create a magnified image of an object.
63
A scientist wants to magnify a pollen grain 8,000 times and examine the ridges and pores on its surface. Which one of the following instruments would be best?
```
A. a transmission light microscope
B. an inverted light microscope
C. a scanning electron microscope
D. a scanning light microscope
E. a transmission electron microscope
```
C. a scanning electron microscope
64
A scientist wants to examine living cells lining the respiratory tract to determine how the cells use tiny hairs to move dirt and mucus away from the lungs. Which one of the following instruments would be best,and why?
A. a light microscope, because it allows observations of whole, live cells
B. a scanning electron microscope, because it can be used to observe whole cells without slicing them
C. a transmission electron microscope, because it has high resolving power
D. a transmission electron microscope, because it is capable of very high magnification
E. a scanning electron microscope, because it can reveal structures on cell surfaces
A. a light microscope, because it allows observations of whole, live cells
65
A scanning electron microscope is used to study ____________, whereas a transmission electron microscope is used to study ___________.
A. cell surfaces..... internal cell structures
B. dead cells..... live cells
C. internal cell structures.....cell surfaces
D. live cells..... dead cells
E. plant tissue..... animal tissue
A. cell surfaces..... internal cell structures
66
A bird egg is a single large cell, whereas a human red blood cell is much smaller, because
A. human blood cells must store a large amount of oxygen.
B. bird eggs contain a smaller amount of nutrients.
C. bird cells are typically larger than human cells.
D. None of the choices are correct.
E. cell size is related to cell function.
E. cell size is related to cell function.
67
Which one of the following is equivalent to one thousandth of a millimeter?
```
A. a nanometer
B. a centimeter
C. a decimeter
D. a micrometer
E. a meter
```
D. a micrometer
68
As cell size increase, the
A. volume increases faster than the surface area.
B. None of the choices are correct.
C. surface area increases faster than the volume.
D. volume and surface area decrease .
E. surface area and volume increase at the same rate.
A. volume increases faster than the surface area.
69
A cell is exposed to a substance that prevents it from dividing. The cell becomes larger and larger. This situation
A. should present no problem to the cell since it can continue to perform all other necessary functions.
B. should present no problem to the cell because the surface area of the cell will increase as the volume if the cell increases.
C. will eventually be problematic since the cell's ability to absorb nutrients through its outer membrane will not keep increasing as quickly as its cytoplasmic needs.
D. should be beneficial since the cell will be able to divert the ATP normally used for cell division to other processes.
E. None of the choices are correct.
C. will eventually be problematic since the cell's ability to absorb nutrients through its outer membrane will not keep increasing as quickly as its cytoplasmic needs.
70
Your throat is dry, and you want the last cough drop in the box to last a long time in your mouth. What should you do?
A. Keep the cough drop whole. This maintains the largest surface-to-volume ratio, and slows the dissolution of the cough drop.
B. It doesn't matter if the cough drop is in one piece or many pieces; the total amount of cough drop is all that matters.
C. Break the cough drop into little pieces, put them all in your mouth, and drink plenty of water.
D. Break the cough drop into little pieces and put them all in your mouth. This decreases the surface-to-volume ratio, and slows the dissolution of the cough drop.
E. Break the cough drop into little pieces and put them all in your mouth. Since each little piece must be dissolved separately, the drop will last longer.
A. Keep the cough drop whole. This maintains the largest surface-to-volume ratio, and slows the dissolution of the cough drop.
71
Which of the following is not found in prokaryotic cells?
```
A. a cell wall
B. pili
C. a capsule
D. a membrane-bound nucleus
E. ribosomes
```
D. a membrane-bound nucleus
72
The nucleoid region of a prokaryotic cell
A. separates the DNA from the cytoplasm.
B. is the site of organelle production.
C. contains the cell's DNA.
D. contains the cell's nucleoli.
E. is surrounded by a nucleoid membrane.
C. contains the cell's DNA.
73
Cells that lack a membrane-bound nucleus are __________________ cells.
```
A. prokaryotic
B. plant
C. animal
D. fungal
E. eukaryotic
```
A. prokaryotic
74
You are told that the cells on a microscope slide are plant. animal, or bacterial. You look at them through a microscope and see the cell walls and membrane-bound organelles. You conclude that the cells
```
A. could be either plant or bacterial.
B. are plant cells.
C. are animal cells.
D. are bacteria.
E. could be plant, animal, or bacterial.
```
B. are plant cells.
75
Peroxisomes
```
A. produce hydrogen peroxide.
B. photosynthesize .
C. synthesize steroids.
D. are a component of cytoskeleton.
E. are not enclosed by a membrane.
```
A. produce hydrogen peroxide.
76
Which of the following structures are used by prokaryotes for attaching to surfaces?
```
A. flagella
B. pili
C. anchoring junctions
D. capsules
E. both pili and capsules
```
E. both pili and capsules
77
Unlike animal cells, plant cells have ____ and ____. Unlike plant cells, animal cells have _____.
A. centrioles....large central vacuoles....cell walls
B. large central vacuoles....cell walls....centrioles
C. chloroplasts....cell walls....cell membranes
D. large central vacuoles....cell walls....cell membranes
E. centrioles....cell walls....large central vacuoles
B. large central vacuoles....cell walls....centrioles
78
Which one of the following statements about cellular metabolism is not true? Cellular metabolism
A. can occur within organelles.
B. includes different processes that require different conditions.
C. occurs in animal but not in plant cells.
D. often occurs on the surfaces of internal membranes.
E. can involve the synthesis of steroid hormones.
C. occurs in animal but not in plant cells.
79
The membranous compartmentalization of a cell
A. divides the cell into two equal-sizes halves.
B. is common in prokaryotes and eukaryotes.
C. requires the presence of a cell wall.
D. requires the presence of a large central vacuole.
E. allows different metabolic processes to occur simultaneously.
E. allows different metabolic processes to occur simultaneously.
80
In eukaryotic cells, internal membranes
A. form membranous compartments called organelles.
B. All of the choices are correct.
C. contain proteins essential for metabolic processes.
D. provide additional area where many metabolic processes occur.
E. greatly increase a cell's total membrane area.
B. All of the choices are correct.
81
The nucleus of a cell
A. is surrounded by a single layer of membrane.
B. is the region of the cell where ribosomes are degraded.
C. is both contained within the nucleolus and contains DNA.
D. contains DNA
E. is contained within the nucleolus.
D. contains DNA
82
Long fibers of DNA and protein are called a
```
A. chromatin
B. nucleolus
C. ribosome
D. central vacuole
E. lysosome
```
A. chromatin
83
During cells reproduction, chromatin coils up into structures called
```
A. nucleoli
B. chromosomes
C. lysosomes
D. peroxisomes
E. ribosomes
```
B. chromosomes
84
The function of the nucleolus is
```
A. to manufacture polypeptides
B. to store chromatin
C. to produce
D. intracellular digestion
E. to help manufacture ribosomes
```
E. to help manufacture ribosomes
85
Which one of the following statements is not true? The endomembrane system
A. is a system in interrelated membranes that are all physically connected.
B. included the nuclear envelope.
C. is involved in the synthesis, storage, and export of important molecules.
D. includes the rough and smooth endoplasmic reticulum.
E. divides the cell into compartments.
A. is a system in interrelated membranes that are all physically connected.
86
The two main funtions of the rough endoplasmic reticulum are the production of
A. chromatin and mitochondria.
B. ribosomes and steroid hormones.
C. mitochondria and proteins that are to be secreted by the cell.
D. hydrogen peroxide and steroid hormones secreted by the cell.
E. more membrane and proteins to be secreted by the cell.
E. more membrane and proteins to be secreted by the cell.
87
Secretory proteins are
A. incorporated into the mitochondrial membrane.
B. produced by the cell for internal use.
C. produced by ribosomes on he smooth endoplasmic reticulum.
D. released from the cell through the plasma membrane.
E. chemically modified in the nucleus .
D. released from the cell through the plasma membrane.
88
The cells that produce hair contain a lot of _____. The cells that the oils that coat the hair contain a lot of _____.
A. smooth endoplasmic reticulum...rough endoplasmic reticulum
B. microbodies...lysosomes
C. nuclei...chromatin
D. rough endoplasmic reticulum...smooth endoplasmic reticulum
E. smooth endoplasmic reticulum....lysosomes
D. rough endoplasmic reticulum...smooth endoplasmic reticulum
89
Chronic administration of a drug (such as a barbiturate or an antibiotic) may cause the liver to
A. produce additional smooth endoplasmic reticulum.
B. increase the production of enzymes that detoxify the drug in question.
C. increase the production of enzymes that break down certain other drugs or foreign substances.
D. increase the body's tolerance to the drug.
E. All of the choices are correct.
E. All of the choices are correct.
90
Smooth endoplasmic reticulum
A. is the major site of carbohydrate synthesis in eukaryotic cells.
B. helps assemble ribosomes for protein synthesis.
C. produces antibodies.
D. produces proteins for cell membranes.
E. stores calcium ions in muscle cells.
E. stores calcium ions in muscle cells.
91
Insulin is a protein that is produced by pancreatic cells and secreted into the bloodstream. Which of the following choices best describes the route of insulin from its production to its exit from the cell?
A. rough ER, smooth ER, transport vesicles, Golgi apparatus, transport vesicles. cell membrane
B. rough ER, transport vesicles, cell membrane.
C. rough ER, lysosomes, transport vesicles, cell membrane/
D. None of the choices are correct.
E. rough ER, Golgi apparatus, smooth ER, cell membrane.
A. rough ER, smooth ER, transport vesicles, Golgi apparatus, transport vesicles. cell membrane
92
The Golgi apparatus
A. stores, modifies, and packages proteins.
B. strings together amino acids to produce proteins.
C. forms fats from glycerols and fatty acids.
D. is composed of stacks of membranous vesicles that are continuous with one another.
E. is the site of carbohydrate breakdown.
A. stores, modifies, and packages proteins.
93
Lysosomes
A. can destroy harmful bacteria engulfed by white blood cells.
B. help to digest worn-out or damaged organelles.
C. All of the choices are correct.
D. recycle materials within the cell.
E. fuse with food vacuoles to expose nutrients to hydrolytic enzymes.
C. All of the choices are correct.
94
When a cell is deprived of oxygen its lysosomes tend to burst and release their contents into the cell. As a result of this, that cell will
```
A. undergo cell division.
B. produce replacement lysosomes.
C. produce additional ER.
D. recycle damaged organelles.
E. undergo autolysis (self-digestion).
```
E. undergo autolysis (self-digestion).
95
Tay-Sachs disease
A. results in an accumulation of triglycerides in the alveoli of the lungs.
B. prevents the breakdown of glycogen.
C. is due to the absence of an enzyme that digests polysaccharides.
D. involves and accumulation of lipids in brain cells.
E. involves damage to liver cells.
D. involves and accumulation of lipids in brain cells.
96
The functions of the central vacuoles of plant cells include
A. all of the choices listed above.
B. helping the cell to grow by absorbing water.
C. storing pigments that will help attract pollinating insects.
D. storing poisons.
E. storing food molecules
A. all of the choices listed above.
97
Contractile vacuoles
A. prevent cells from bursting as a result of the influx of excess water.
B. allow organisms to avoid dehydration by absorbing water from the environment.
C. are generally found in protists that inhabit salt water.
D. help in the excretion of excess salt.
E. All of the choices are correct.
A. prevent cells from bursting as a result of the influx of excess water.
98
A manufacturing company dumps its waste into a nearby pond. One of the wastes is found to paralyze the contractile vacuoles of certain protists. A biologist looking at one of the organisms would find that the organism
A. has died of malnutrition.
B. has died because wastes have built up in the cytoplasm.
C. has lost water and shrunk.
D. has gained water and burst.
E. is surviving but is unable to reproduce.
D. has gained water and burst.
99
Which one of the following is not a component of the endomembrane system?
```
A. smooth ER
B. Golgi apparatus
C. lysosomes
D. ribosomes
E. nucleus
```
D. ribosomes
100
Mitochondria differ from chloroplasts in that mitochondria
A. produce glucose, whereas chloroplasts break gluclose down.
B. contain three different membrane-bound compartments, whereas chloroplasts contain two.
C. are not found in plants, whereas chloroplasts are not found in animals.
D. convert solar energy to chemical energy, whereas chloroplasts convert one form of chemical energy to another.
E. contain membrane folds called cristae, whereas chloroplasts contain disklike vesicles in stacks called grana.
E. contain membrane folds called cristae, whereas chloroplasts contain disklike vesicles in stacks called grana.
101
The stroma is the
A. thick fluid enclosed by the inner chloroplast membrane.
B. space between the inner and outer membranes of a mitochondrion.
C. fluid within the grana.
D. watery fluid enclosed by the inner membrane of a mitochondrion.
E. space between the inner and outer membrane of a chloroplast.
A. thick fluid enclosed by the inner chloroplast membrane.
102
The function of chloroplasts is
```
A. intercellular transport of proteins.
B. intracellular digestion.
C. lipid synthesis.
D. cellular respiration
E. photosynthesis.
```
E. photosynthesis.
103
The function of mitochondria is
```
A. photosynthesis
B. intracellular transport of proteins.
C. intracellular digestion.
D. lipid synthesis
E. cellular respiration.
```
E. cellular respiration.
104
The ________ of a mitochondrion is/are adaptation that increass the surface area and enhances a mitochondrion's ability to produce ATP.
```
A. stroma
B. intermembrane space
C. cristae
D. matrix
E. grana
```
C. cristae
105
Cyanide inhibits mitochondrial function; as a result, the rate of
```
A. ATP synthesis would decrease.
B. ATP synthesis would increase.
C. protein synthesis would increase.
D. photosynthesis would increase.
E. lipid synthesis would increase
```
A. ATP synthesis would decrease.
106
Microfilaments differ from microtubules in that microfilaments
A. are found only in plants and microtubules are found in plants and animal cells
B. are mainly composed of actin and microtubules are composed of with tubilin.
C. form the inner core of cilia and flagella and microtubules regulate metabolism.
D. help to anchor organelles, whereas microtubules primarily function to help cells change shape and move.
E. are larger than microtubules.
B. are mainly composed of actin and microtubules are composed of with tubilin.
107
Which of the following statements about the cytoskeleton is not true?
A. It is composed of three types of fibers: microfilamentss, microtubules, and intermediate filaments.
B. Once laid down, the elements of the cytoskeleton are fixed and remain permanently in place.
C. It includes both fibrous and globular proteins.
D. It helps support cells.
E. It plays an important role in amoeboid.
B. Once laid down, the elements of the cytoskeleton are fixed and remain permanently in place.
108
Intermediate filaments function as
A. guides for the movement of organelles.
B. guides for the movement of chromosomes .
C. a structural component of cilia and flagella.
D. tension-bearing elements.
E. supports for the inner mitochondrial membrane.
D. tension-bearing elements.
109
A drug interferes with microtubule formation is likely to completely disrupt
```
A. contraction of muscle cells.
B. the ability of sperm cells to move.
C. the production of ribosomes.
D. the amoeboid motion of a cell.
E. the function of lysosomes.
```
B. the ability of sperm cells to move.
110
Cilia differ from flagella in that
A. the protein filaments of cilia are "naked", those of flagella are wrapped in an extension of the cell membrane.
B. cillia are composed of microfilaments and flagella are composed of intermediate filaments.
C. cilia are typically shorter than flagella.
D. cilia are anchored only in the proteins of the cell membrane; flagella are anchored in a special structure called the basal body.
E. cilia contain nine microtubule doublets surrounding a central pair of microtubules; flagella contain only nine microtubule doublets.
C. cilia are typically shorter than flagella.
111
A basal body is
A. composed of nine microtubule triplets surrounding a central pair of microtubules.
B. identical in structure to cilia.
C. identical in structure to centrioles.
D. identical in structure of flagella.
E. composed of nine microtubule doublets surrounding a central pair of microtubules.
C. identical in structure to centrioles.
112
Dynein arms
A. are the anchoring proteins in basal bodies.
B. join microfilaments to the cell membrane.
C. are present in cilia but not in flagella.
D. are found on microtubules in cilia and flagella and cause movement by grabbing and pulling at adjacent microtubule doublets.
E. are knobs of carbohydrate that are essential to the movement of cilia and flagella.
D. are found on microtubules in cilia and flagella and cause movement by grabbing and pulling at adjacent microtubule doublets.
113
A women is having trouble becoming pregnant. Examination of her partner's sperm indicates that dynein arms are missing from the flagella in his sprem cells. A physician explains that this could interfere with fertility by
A. preventing the sperm from attaching to the egg cell.
B. preventing the sperm from producing enough energy to power swimming.
C. interfering with the attachment of the flagella to the sperm.
D. preventing the sperm from swimming to the egg cell.
E. interfering with the ability of the sperm to tolerate the acid conditions in the vaginal canal.
D. preventing the sperm from swimming to the egg cell.
114
Which one of the following statements about plant cell walls is not true?
A. Plant cell walls protect plant cells by forming an impermeable layer around the cell.
B. Plant cell walls consist of cellulose fibers embedded in a matrix of polysaccharides and proteins.
C. Plant cell walls are multi-layered structures.
D. The cell wall of one plant cell is separated from the cell wall of another by a layer of sticky polysaccharides.
E. Wood is primarily composed of plant cell walls.
A. Plant cell walls protect plant cells by forming an impermeable layer around the cell.
115
Plasmodesmata
A. carry nutrients between plant cells
B. are one type of cell junction in plants.
C. penetrate plant cell walls.
D. All of the choices are correct.
E. carry chemical messages between plant cells.
D. All of the choices are correct.
116
Which one of the following would be most affected by a mutation that prevented cells from forming tight junctions.
A. integrity of the inner lining of the digestive tract
B. attachment of the cytoskeleton to the inside of the plasma membrane
C. direct flow of water and small molecules from one cell to another
D. attachment of the cell wall of one plant cell to the cell wall of another
E. attachment of cells to the surrounding matrix
A. integrity of the inner lining of the digestive tract
117
Most animal cells are
A. embedded in an extracellular matrix.
B. attached to each other via plasmodesmata.
C. embedded in a lipid matrix.
D. embedded in an endomembrane system.
E. surrounded by a cell wall.
A. embedded in an extracellular matrix.
118
It is essential for heart muscle cells to beat in a coordinated fashion. The cell junctions that would best facilitate this are
```
A. anchoring junctions
B. occluding junctions
C. communicating junctions
D. plasmodesmata
E. tight junctions
```
C. communicating junctions
119
Skin cells are attached to the extracellular matrix by
```
A. plasmodesmata.
B. communicating junctions.
C. basal bodies.
D. anchoring junctions.
E. tight junctions.
```
D. anchoring junctions.
120
Which of the following cell structures is not associated with the breakdown of harmful substances that are no longer needed by the cell?
```
A. lysosomes
B. mitochondria
C. vacuoles
D. peroxisomes
E. All of the choices play a role in the breakdown of substances that are no longer needed by the cell.
```
B. mitochondria
121
All cells on Earth
A. can interconvert chemical materials.
B. are enclosed in a membrane that maintains internal conditions different from the surroundings.
C. have DNA as the genetic material.
D. All of the choices are correct.
E. can interconvert forms of energy.
D. All of the choices are correct.
122
A child is hospitalized for a series of chronic bacterial infections and dies despite heroic efforts. At autopsy, the physicians are startled to see that the child's white blood cells are loaded with vacuoles containing intact bacteria. Which of the following explanations could account for this finding? A defect in the
A. cell walls of the white blood cells permitted bacteria to enter the cells.
B. surface receptors of the white blood cells permitted bacteria to enter the cells.
C. rough endoplasmic reticulum prevented the synthesis of the antibodies (defensive proteins) that would have inactivated the bacteria.
D. lysosomes of the white blood cells prevented the cells from destroying engulfed bacteria.
E. Golgi apparatus prevented the cells from processing and excreting the bacteria.
D. lysosomes of the white blood cells prevented the cells from destroying engulfed bacteria.
123
Geckos are able to walk up walls and across ceilings because of the
A. many setae on the gecko's toes that form molecular bonds with the surface.
B. sticky adhesive secretions on their feet.
C. sticky saliva licked onto the regions where the gecko is about to walk.
D. None of the choices are correct
.
E. little suction cups on their toes.
A. many setae on the gecko's toes that form molecular bonds with the surface.
124
The connection between structure and __________ is a basic concept of biology.
```
A. species
B. strength
C. adaptation
D. sex
E. function
```
E. function
125
A physiologist is a biologist who studies
```
A. the function of body parts.
B. the anatomy of living things.
C. the structure of body parts.
D. the evolution of animals.
E. the structure of living things.
```
A. the function of body parts.
126
Which of the following is not an example of how structural adaptations give a bird its ability to fly?
A. Interlocking barbules make the feathers strong.
B. The weight of flight muscles is largely kept off the wings.
C. Feathers are produced by special pits in the bird's skin.
D. Many of the wing bones are hollow but are reinforced internally with trusses.
E. The bird wing has more bones than the human arm.
E. The bird wing has more bones than the human arm.
127
Structure in the living world is organized at hierarchical levels. Which of the following choices lists several of these, from least inclusive to most inclusive?
A. molecule, cell, tissue, organ, organ system, organism
B. molecule, cell, tissue, organ system, organ, organism
C. cell, molecule, tissue, organ, organ system, organism
D. molecule, cell, organ, organ system, tissue, organism
E. cell, molecule, organ, organ system, tissue, organism
A. molecule, cell, tissue, organ, organ system, organism
128
Which of the following is not a major category of animal tissue?
```
A. muscle
B. connective
C. nervous
D. cardiac
E. epithelial
```
D. cardiac
129
Stratified squamous epithelium is well suited for
A. exchanging materials by active transport.
B. lining our lungs.
C. exchanging materials by diffusion.
D. lining surfaces subject to abrasion.
E. secreting mucus.
D. lining surfaces subject to abrasion.
130
A stratified squamous epithelium is found in the
```
A. kidney.
B. brain.
C. esophagus.
D. liver.
E. heart.
```
C. esophagus.
131
A main function of most types of epithelial tissue is
```
A. sensation.
B. support.
C. absorption.
D. covering surfaces.
E. contraction.
```
D. covering surfaces.
132
Which of the following statements is not true of the cells of the mucous membrane lining your breathing tubes?
A. They carry cilia that sweep mucus up and out of the respiratory system.
B. They form an abrasion-resistant covering.
C. They have a large volume of cytoplasm.
D. They manufacture secretory products.
E. They are cuboidal or columnar in shape.
B. They form an abrasion-resistant covering.
133
Which of the following is not a type of connective tissue?
```
A. blood
B. cartilage
C. bone
D. fat
E. plasma
```
E. plasma
134
Which one of the following types of tissues stores fat in the body?
```
A. adipose tissue
B. blood
C. cartilage
D. fibrous connective tissue
E. bone
```
A. adipose tissue
135
What kind of connective tissue has a liquid matrix?
```
A. loose connective tissue
B. nerve tissue
C. adipose tissue
D. blood
E. cartilage
```
D. blood
136
Connective tissue is different from the other major tissue types in that
A. it is found only in humans.
B. the cells are sparsely scattered through a nonliving matrix.
C. it is not made up of cells.
D. it is made up of cells.
E. it has no essential function in an animal's body.
B. the cells are sparsely scattered through a nonliving matrix.
137
Which of the following is the most common type of connective tissue in the typical human body?
```
A. adipose tissue
B. fibrous connective tissue
C. loose connective tissue
D. loose adipose tissue
E. bone
```
C. loose connective tissue
138
Which is the most abundant kind of tissue in an animal such as a zebra?
```
A. blood
B. muscle
C. connective
D. nerve
E. epithelial
```
B. muscle
139
Which of the following is not true of a typical skeletal muscle?
A. It can be contracted at will.
B. Its fibers have a striped appearance under the microscope.
C. Its individual cells can sustain contractions longer than smooth muscle cells can.
D. It can be enlarged by exercise.
E. It is attached to bones by tendons.
C. Its individual cells can sustain contractions longer than smooth muscle cells can.
140
Which of the following distinguishes cardiac muscle from both smooth and skeletal muscle?
A. Its cells contract.
B. It generally can be contracted at will.
C. It generally cannot be contracted at will.
D. Its cells are branched.
E. Its cells are striped.
D. Its cells are branched.
141
The main function of muscle tissue is
```
A. sensation.
B. covering surfaces.
C. absorption.
D. contraction.
E. support.
```
D. contraction.
142
Which type of tissue forms a communication and coordination system within the body?
```
A. connective
B. blood
C. muscle
D. epithelial
E. nervous
```
E. nervous
143
The structural and functional unit of nervous tissue is
```
A. the cell body.
B. the nerve.
C. the axon.
D. the dendrite.
E. the neuron.
```
E. the neuron.
144
Which of the following is not a true statement about organs?
A. An organ can only carry out the functions of its component tissues.
B. Organs are found in virtually all animals except sponges.
C. An organ consists of many cells.
D. An organ consists of several tissues.
E. An organ represents a higher level of structure than the tissues composing it.
A. An organ can only carry out the functions of its component tissues.
145
Which one of the following tissues would not likely be found in the heart?
A. simple squamous epithelium
B. cartilage
C. cardiac muscle
D. nervous tissue
B. cartilage
146
The respiratory system includes all of the following structures except the
```
A. trachea.
B. larynx.
C. esophagus.
D. air sacs.
E. bronchus.
```
C. esophagus.
147
Which organ system is not essential for survival of an individual?
```
A. lymphatic system
B. reproductive system
C. excretory system
D. integumentary system
E. muscular system
```
B. reproductive system
148
Nails are a component of the __________ system.
```
A. excretory
B. skeletal
C. muscular
D. respiratory
E. integumentary
```
E. integumentary
149
Suppose your doctor decides to X-ray your hip. Which would show up more distinctly, the muscle or the bones? Why?
A. the muscle, because it is richer in hydrogen
B. the bones, because they are denser
C. the muscle, because it is metabolically more active
D. the muscle, because it is softer
E. the bones, because they are richer in hydrogen
B. the bones, because they are denser
150
Conventional X-ray imaging is routinely used to check for all of the following except
```
A. brain diseases.
B. bone tumors.
C. broken bones.
D. torn cartilages.
E. tooth cavities.
```
A. brain diseases.
151
Which of the following imaging techniques is best suited for visualizing fine anatomic detail in the brain?
```
A. positron-emission tomography
B. computerized tomography
C. X-ray tomography
D. magnetic resonance imaging
E. X-ray imaging
```
D. magnetic resonance imaging
152
Which of the following imaging techniques is best suited for visualizing areas of high or low metabolic activity?
```
A. computerized tomography
B. X-ray tomography
C. magnetic resonance imaging
D. positron-emission tomography
E. X-ray imaging
```
D. positron-emission tomography
153
Which of the following imaging techniques makes it possible to see which areas of the brain are active during particular types of mental activity?
```
A. magnetic resonance imaging
B. X-ray tomography
C. positron-emission tomography
D. X-ray imaging
E. computerized tomography
```
C. positron-emission tomography
154
What fills the spaces between cells in animals more complex than Hydra?
```
A. water
B. nothing but matrix fibers
C. cytoplasm
D. interstitial fluid
E. connective tissue
```
D. interstitial fluid
155
Which of the following is a way in which the freshwater animal Hydra differs from a trout?
```
A. Hydra has a gastrovascular cavity.
B. Hydra has a smaller surface-to-volume ratio.
C. Hydra has a larger brain.
D. Hydra has thinner blood.
E. Hydra has a smaller heart.
```
A. Hydra has a gastrovascular cavity.
156
Imagine an invertebrate that lives in an estuary where salinity varies cyclically with the tides. If this animal practices homeostasis with respect to the salt concentration of its body fluids, its salt concentration will show
A. a cyclic variation identical to that of the surrounding water.
B. a cyclic variation similar to that of the surrounding water but less intense.
C. slight, continuous fluctuations due to the "play" in the control mechanism.
D. slight variations, but only when the external salinity is changing rapidly.
E. no variations.
C. slight, continuous fluctuations due to the "play" in the control mechanism.
157
In complex animals, which of the following organ systems would you not expect to have a large epithelial surface area?
```
A. circulatory system
B. excretory system
C. digestive system
D. respiratory system
E. muscular system
```
E. muscular system
158
Homeostasis
A. is the maintenance of a dynamic equilibrium.
B. is a pathological condition.
C. only comes into play when you are ill.
D. is the maintenance of a constant external state.
E. is the way the internal environment influences the external environment.
A. is the maintenance of a dynamic equilibrium.
159
A mouse's cells are much more active metabolically than a frog's. Which of the following organs or systems would you expect to have a larger surface area in a mouse than in a same-sized frog?
```
A. None of the choices are correct.
B. All of the choices are correct.
C. lung
D. intestine
E. circulatory system
```
B. All of the choices are correct.
160
The vertebrate kidney helps to keep the acidity of the body fluids constant by varying the amount of hydrogen ions () it secretes into the urine. You can confidently predict that this aspect of kidney function will be controlled by
A. a hormone ultimately controlled by the brain.
B. a positive feedback mechanism.
C. a hormone produced in the kidney itself.
D. nerve impulses from the brain.
E. a negative feedback mechanism.
E. a negative feedback mechanism.
161
Which of the following is most likely to be responsible if, when your blood sugar level rose, the level went back down?
A. type II diabetes
B. diabetes insipidus
C. a homeostatic mechanism based on negative feedback
D. the use of the sugar for energy by your cells
E. a homeostatic mechanism based on positive feedback
C. a homeostatic mechanism based on negative feedback
162
Homeostasis depends on
A. positive and negative feedback control.
B. predictable environmental conditions.
C. predictable internal conditions.
D. negative feedback control.
E. positive feedback control.
D. negative feedback control.
163
When body temperature is too high, which of the following does not occur?
A. Blood vessels at the body surface fill with warm blood.
B. Evaporative cooling occurs.
C. The thermostatic control center of the brain is activated.
D. Blood vessels in the skin contract.
E. Heat radiates from the skin.
D. Blood vessels in the skin contract.
164
Biologists claim which is the foundation for the unity of life?
```
A. Enzymes
B. DNA
C. Protein
D. RNA
E. Lipid
```
B. DNA
165
In figure 1.6B in the text, the images are illustrating natural selection. Is the genetic diversity (gene pool) increasing or
decreasing?
(1st pic has 4 different colored bugs, 2nd pic has bird eating light colored bugs, 3rd pic has same amount of bugs but all are dark colored now)
decreasing
166
Life is organized in a hierarchical fashion. Which one of the following sequences illustrates that hierarchy as it increases in complexity?
A. molecule, cell, tissue, organ, organ system, organism, population, community, ecosystem
B. ecosystem, molecule, cell, tissue, organism, organ system, organ, community
C. organism, organ system, tissue, population, organ, community, cell, ecosystem, molecule
D. ecosystem, population, organ system, cell, community, molecule, organ, organism, tissue
E. cell, molecule, organ system, organ, population, tissue, organism, ecosystem, community
A. molecule, cell, tissue, organ, organ system, organism, population, community, ecosystem
167
The tree in your backyard is home to two cardinals, a colony of ants, wasps, two squirrels, and millions of bacteria. Together, all these organisms are
```
A. a species.
B. a community.
C. a population.
D. an ecosystem.
E. a community and a population.
```
B. a community.
168
A hypothesis
A. is a widely accepted theory that is broad in scope and supported by a large body of evidence.
B. is a widely accepted idea about a phenomenon.
C. is the same as a theory.
D. is an explanatory idea that is broad in scope and supported by a large body of evidence.
E. is a tentative explanation for a specific phenomenon.
E. is a tentative explanation for a specific phenomenon.
169
If a light switch is moved from the "off" to the "on" position, then the light will go on. This statement
```
A. is the result of deductive reasoning.
B. is a prediction.
C. can be tested.
D. can be falsified.
E. All of the choices are correct.
```
E. All of the choices are correct.
170
To be scientifically valid, a hypothesis must be
```
A. testable.
B. based on faith.
C. falsifiable.
D. testable and falsifiable.
E. phrased as a question.
```
D. testable and falsifiable.
171
A scientist performs a controlled experiment. This means that
A. the experiment proceeds at a slow pace to guarantee that the scientist can carefully observe all reactions and process all experimental data.
B. the experiment is repeated many times to ensure that the results are accurate.
C. two experiments are conducted, one differing from the other by two or more variables.
D. two experiments are conducted, one differing from the other by only a single variable.
E. one experiment is performed, but the scientist controls the variables.
D. two experiments are conducted, one differing from the other by only a single variable
172
In the potato lab experiment, the statement "The potato in Tube 1 will show no change" is an example of
```
A. a hypothesis.
B. the experimental question.
C. an expected result.
D. the experiment.
E. an observation.
```
A. a hypothesis.
173
Consider the following statement: "If all vertebrates have backbones, and turtles are vertebrates, then turtles have backbones." This statement is an example of
```
A. a hypothesis.
B. hypothetico-deductive reasoning.
C. an observation.
D. discovery science logic.
E. rationalization.
```
B. hypothetico-deductive reasoning.
174
The role of a control in an experiment is to
A. provide a basis of comparison to the experimental group.
B. prove that a hypothesis is correct.
C. ensure repeatability.
D. prove that a hypothesis is correct and ensure repeatability.
E. None of the choices are correct.
A. provide a basis of comparison to the experimental group.
175
Organisms that are not prokaryotes are in the Domain
```
A. Archaea.
B. Bacteria.
C. Fungi.
D. Eukarya.
E. Monera.
```
D. Eukarya.
176
Which one of the following is a kingdom within the Domain Eukarya?
```
A. Archaea
B. Monera
C. Fungi
D. Viruses
E. Protista
```
C. Fungi
177
Which one of the following statements is true of the Domain Bacteria?
A. All bacteria have a membrane-bound nucleus.
B. All bacteria are multi-cellular organisms.
C. All bacteria are "animal-like" in that they eat other organisms.
D. All bacteria lack a nucleus.
E. All bacteria are "animal-like" in that they eat other organisms and all bacteria have a membrane-bound nucleus.
D. All bacteria lack a nucleus.
178
A scientist examining a group of cells under the microscope notices the presence of nuclei within these cells. Chemical tests reveal that each cell is surrounded by a wall composed of cellulose. These cells must come from an organism that is a member of the Kingdom
```
A. Fungi.
B. Monera.
C. Protista.
D. Plantae.
E. Animalia.
```
D. Plantae.
179
Organisms belonging to the Kingdom Plantae
A. are photosynthetic.
B. contain cells that are surrounded by cell walls.
C. are unicellular.
D. are photosynthetic and contain cells that are surrounded by cell walls.
E. lack a nucleus.
D. are photosynthetic and contain cells that are surrounded by cell walls.
180
Members of the Kingdom Fungi
A. include the mushrooms and yeasts, and decompose the remains of dead organisms and absorb nutrients from the leftovers.
B. decompose the remains of dead organisms and absorb nutrients from the leftovers.
C. use photosynthesis to produce their own food.
D. include the mushrooms.
E. include the yeasts.
A. include the mushrooms and yeasts, and decompose the remains of dead organisms and absorb nutrients from the leftovers.
181
Members of the Kingdom Animalia
A. are composed of cells that are surrounded by a cell wall and that lack a cell membrane.
B. can obtain their food either by absorption or by photosynthesis.
C. are composed of cells that lack a cell membrane.
D. are composed of cells that are surrounded by a cell wall.
E. are composed of cells that lack a cell wall.
E. are composed of cells that lack a cell wall.
182
Which of the following is/are properties of life?
A. the ability to take in energy and use it
B. a complex organization
C. All of the choices are correct.
D. the ability to reproduce
E. the ability to respond to stimuli from the environment
C. All of the choices are correct.
183
Which one of the following statements is correct?
A. The DNA of humans is more similar to the DNA of birds than it is to that of apes.
B. Each organism has its own unique DNA code.
C. Genes are proteins that produce DNA.
D. Each DNA molecule is a single strand of nucleotides.
E. Differences among organisms reflect different nucleotide sequences in their DNA.
E. Differences among organisms reflect different nucleotide sequences in their DNA.
184
Which one of the following observations would provide the strongest evidence that the many different plants we call orchids are actually related to one another?
A. They all have the same common ancestor.
B. They all produce small seeds.
C. They all attract insect pollinators.
D. None of them can grow without the presence of a specific type of fungus.
E. The flowers have the same shape of petals.
A. They all have the same common ancestor.
185
An antibiotic kills 99.9% of a bacterial population. You would expect the next generation of bacteria
A. to die out due to the drastic decrease in population size.
B. to be just as susceptible to that antibiotic as was the previous generation.
C. to be more resistant to that antibiotic.
D. to be more contagious than the prior generation.
E. All of the choices are correct.
C. to be more resistant to that antibiotic
186
Which of the following is/are true about ecosystems?
A. All of the choices are true.
B. The bacteria and fungi are responsible for recycling the mineral nutrients within an ecosystem.
C. Plants, photosynthetic bacteria, and photosynthetic protists are the ultimate sources of food in ecosystems.
D. Nutrients are cycled through ecosystems.
E. The "web of relationships" within an ecosystem includes the nonliving components of the environment.
A. All of the choices are true
187
The ultimate source of energy flowing into nearly all ecosystems is
```
A. radioactivity.
B. electricity.
C. geothermal vents.
D. wind.
E. sunlight.
```
E. sunlight.
188
Ethanol boils at a lower temperature than water. Which has stronger hydrogen bonding based on this observation?
A. water
B. Ethanol
A. water
189
Before they attempt to understand the properties of molecules, scientists first try to understand the atoms found in the molecules. This illustrates
```
A. a reductionist approach to science.
B. a holistic approach to science.
C. the emergent properties of matter.
D. an existential approach to science.
E. that the whole is greater than the sum of its parts.
```
A. a reductionist approach to science.
190
Which one of the following is not a trace element in the human body?
```
A. fluorine
B. zinc
C. manganese
D. iodine
E. nitrogen
```
E. nitrogen
191
The five most common elements in living organisms are
```
A. C, N, O, Na, Cl.
B. C, H, O, N, Ca.
C. C, H, O, Na, Cl.
D. C, N, O, Ca, Fe.
E. C, H, O, Na, Ca.
```
B. C, H, O, N, Ca.
192
Matter
```
A. is what life is composed of.
B. occupies space.
C. has mass.
D. is composed of elements.
E. All of the choices are correct.
```
E. All of the choices are correct.
193
In the equation 2H2 + O2 = 2H2O
A. H2 , O2, and H2O are all molecules but only H2O is a compound.
B. only H2O is a compound.
C. H2 and O2 are elements.
D. H2, O2, and H2O are all molecules.
E. H2 , O2, and H2O are all compounds.
A. H2 , O2, and H2O are all molecules but only H2O is a compound
194
A compound
```
A. is a pure element.
B. is exemplified by sodium.
C. contains two or more elements in a fixed ratio.
D. is less common than a pure element.
E. is a solution.
```
C. contains two or more elements in a fixed ratio.
195
The nucleus of an atom contains
```
A. only protons.
B. only neutrons.
C. protons and neutrons.
D. only electrons.
E. protons and electrons.
```
C. protons and neutrons.
196
Electrons move about the nucleus of an atom in the same way that
A. insects fly around a bright lamp at night.
B. cars are parked along the sides of a street.
C. boats cross a lake.
D. people pass each other along a sidewalk.
E. birds migrate to a new winter home.
A. insects fly around a bright lamp at night.
197
The atom sodium contains 11 electrons, 11 protons, and 12 neutrons. What is the mass number of sodium?
A. 22
B. 34
C. 23
D. 11
C. 23
198
The atomic number of an atom is
A. the number of protons, electrons, and neutrons in the atom.
B. the number of protons in the atom.
C. the net electrical charge of the atom.
D. the number of neutrons in the atom.
E. the number of electrons in the atom.
B. the number of protons in the atom.
199
Typically, nitrogen atoms are composed of seven electrons, seven protons, and seven neutrons. An isotope of nitrogen could
A. have more than seven each of electrons, protons, and neutrons.
B. be negatively charged.
C. have more than seven neutrons.
D. be positively charged.
E. have more than seven electrons and more than seven protons.
C. have more than seven neutrons.
200
A radioactive isotope is one that
A. has more protons than the common variant of the element.
B. has more electrons than the common variant of the element.
C. is stable.
D. decays.
E. has the same atomic mass, but a different atomic number than the common variant of the element.
D. decays.
201
Which of the following statements about radioactive isotopes is/are true?
A. The nuclei of radioactive isotopes are unusually stable, but the atoms tend to lose electrons.
B. All of the choices are true.
C. The energy emitted by radioactive isotopes can break chemical bonds and cause molecular damage in cells.
D. The tracers typically used for diagnosing medical problems remain radioactive in the body for a number of years, but give off very low levels of radioactive energy.
E. When given a choice between radioactive and nonradioactive isotopes of the same atom, living cells are more likely to incorporate the radioactive isotopes into their structures.
C. The energy emitted by radioactive isotopes can break chemical bonds and cause molecular damage in cells.
202
Radioactive isotopes
A. can be used in conjunction with PET scans to diagnose a patient.
B. are never incorporated into organic compounds.
C. never occur naturally.
D. have no effect on living tissue.
E. have no medical usage.
A. can be used in conjunction with PET scans to diagnose a patient.
203
When full, the innermost electron shell of an atom contains __________ electrons, and the outermost shell contains __________ electrons.
```
A. 2 . . . 8
B. 4 . . . 8
C. 8 . . . 2
D. 8 . . . 8
E. 2 . . . 2
```
A. 2 . . . 8
204
The further an electron is from the nucleus, the
A. more likely it is to be radioactive.
B. more unstable the isotope.
C. greater its energy.
D. lower the atomic number.
E. more inert the atom.
C. greater its energy.
205
Table salt is formed when
A. sodium and chlorine share electrons to form a bond.
B. chlorine gives an electron to sodium.
C. a hydrogen bond forms between sodium and chlorine.
D. None of the statements are true.
E. sodium crystals combine with chlorine crystals.
D. None of the statements are true.
206
The body uses atoms in different ways to accomplish different tasks. For example, one portion of the body's calcium supply strengthens bones, whereas another portion combines with proteins to stimulate blood clotting after tissue injury. Which of the statements below provides the most logical chemical explanation of calcium's ability to perform such different functions?
A. The bone contains calcium salts, which are less reactive than the calcium ions found in the blood.
B. There are many different isotopes of calcium, and the most reactive isotope is found in the bone.
C. The calcium in blood has fewer protons, is a more reactive form of the atom, and has a lighter atomic mass than the calcium in bone.
D. The calcium in blood is a more reactive form of the atom and therefore has fewer protons than the calcium in bone.
E. The calcium in blood has a lighter atomic mass than the calcium in bone and is in a more reactive form.
A. The bone contains calcium salts, which are less reactive than the calcium ions found in the blood.
207
Medicines are often administered in pill form. In many cases, the active ingredient of the pill (the drug) is joined to another substance by __________. This forms a(n) __________, which is stable in the dry environment of a pill bottle but dissociates under the wet conditions of the digestive system to release the drug to the body.
A. polar covalent bonds . . . acid or base (depending on the drug)
B. ionic bonds . . . acid
C. ionic bonds . . . salt
D. covalent bonds . . . salt
E. hydrogen bonds . . . base
C. ionic bonds . . . salt
208
A(n) __________ forms when two atoms share electrons.
```
A. ionic bond
B. polar covalent bond
C. ion
D. polar covalent bond or covalent bond
E. covalent bond
```
D. polar covalent bond or covalent bond
209
What is the fundamental difference between covalent and ionic bonding?
A. In a covalent bond, the partners have identical electronegativity; in an ionic bond, one of them is more electronegative.
B. In covalent bonding, both partners end up with filled outer electron shells; in ionic bonding, one partner does and the other does not.
C. In a covalent bond, the partners share a pair of electrons; in an ionic bond, one partner captures an electron from the other.
D. Covalent bonding involves only the outer electron shell; ionic bonding also involves the next inner electron shell.
E. Covalent bonds form between atoms of the same element; ionic bonds, between atoms of different elements.
C. In a covalent bond, the partners share a pair of electrons; in an ionic bond, one partner captures an electron from the other.
210
The oxygen atom of a water molecule
A. is electrically neutral.
B. is more electronegative than the hydrogen atoms.
C. is more positively charged than the hydrogen atoms.
D. is attracted to the negatively charged atoms of other molecules.
E. attracts electrons less strongly than the hydrogen atoms.
B. is more electronegative than the hydrogen atoms.
211
Many fabrics are coated with a "water-repellent" chemical that causes water to bead on the fabric instead of soaking in. This probably occurs because
A. the coating has positive charges that repel the positively charged ends of the water molecules.
B. the coating has negative charges that repel the negatively charged ends of the water molecules.
C. the coating is neutral and repels the positive and negative ends of the water molecules.
D. the coating has positive charges that repel the positively charged ends of the water molecules and also has negative charges that repel the negatively charged ends of the water molecules.
E. the coating is neutral, and therefore repels water, which is also neutral.
C. the coating is neutral and repels the positive and negative ends of the water molecules.
212
A water molecule (H-O-H) is held together by
```
A. an ionic bond.
B. hydrogen bonds.
C. a polar covalent bond.
D. a double covalent bond.
E. a single covalent bond.
```
C. a polar covalent bond.
213
The hydrogen atoms of a water molecule are bonded to the oxygen atom by __________ bonds, whereas neighboring water molecules are held together by __________ bonds.
```
A. hydrogen . . . polar covalent
B. ionic . . . covalent
C. hydrogen . . . ionic
D. polar covalent . . . ionic
E. polar covalent . . . hydrogen
```
E. polar covalent . . . hydrogen
214
__________ are weak bonds that are not strong enough to hold atoms together to form molecules but are strong enough to form bridges between molecules.
```
A. Hydrogen bonds
B. Ionic bonds
C. Polar covalent bonds
D. Anionic bonds
E. Covalent bonds
```
A. Hydrogen bonds
215
Water molecules stick to other water molecules because
A. the hydrogen atoms of adjacent water molecules are attracted to one another.
B. water molecules are neutral, and neutral molecules are attracted to each other.
C. the oxygen atoms of adjacent water molecules are attracted to one another.
D. covalent bonds form between the hydrogen atoms of one water molecule and the oxygen atoms of other water molecules.
E. hydrogen bonds form between the hydrogen atoms of one water molecule and the oxygen atoms of other water molecules.
E. hydrogen bonds form between the hydrogen atoms of one water molecule and the oxygen atoms of other water molecules.
216
The ability of water molecules to form hydrogen bonds with other water molecules is critical to
A. evaporative cooling of skin surfaces.
B. the movement of water from the roots of a tree to its leaves.
C. the milder temperatures of coastal regions when compared to inland areas.
D. the ability of certain insects to walk on the surface of water.
E. all of these factors.
E. all of these factors.
217
After turning the water off at the end of a shower, water still clings to your body because of
```
A. cohesion.
B. evaporative cooling.
C. All of the choices are correct.
D. adhesion.
E. water's versatility as a solvent.
```
D. adhesion.
218
As ice melts,
A. hydrogen bonds are broken.
B. water molecules become less tightly packed.
C. the water becomes less dense.
D. covalent bonds form.
E. All of the choices are true.
A. hydrogen bonds are broken.
219
The temperature of evaporation is much higher for water than for alcohol. Without knowing more about the chemistry of alcohol, which of the following is the most logical chemical explanation for this phenomenon?
A. Ionic bonds form between alcohol molecules. These are the weakest type of bond and are easier to break than the hydrogen bonds between water molecules.
B. Alcohol has a higher surface tension than water. This means that alcohol molecules can easily break away from other alcohol molecules and evaporate at a lower temperature.
C. Alcohol molecules are more cohesive than water molecules. This means that as alcohol molecules evaporate, they pull other alcohol molecules into the air along with them.
D. Fewer hydrogen bonds form between alcohol molecules. As a result, less heat is needed for alcohol molecules to break away from solution and enter the air.
E. None of the choices is a logical chemical explanation for this phenomenon.
D. Fewer hydrogen bonds form between alcohol molecules. As a result, less heat is needed for alcohol molecules to break away from solution and enter the air.
220
You've made a hot drink by dissolving a teaspoon of instant coffee and a teaspoon of sugar in a cup of hot water. Which of the following is/are true?
A. You've just prepared an aqueous solution.
B. The water is the solute portion of the drink.
C. The instant coffee and sugar are solvents.
D. The instant coffee and sugar dissolve because they have no electropositive or electronegative regions to repel the electropositive and electronegative regions of the water molecules.
E. All of the choices are true.
A. You've just prepared an aqueous solution.
221
Which of the following is not related to the ability of NaCl to dissolve in water?
A. Water is a polar compound.
B. Ionic bonds tend to dissociate in water.
C. Positively charged substances are attracted to negatively charged substances.
D. The atoms of this salt are held together by ionic bonds.
E. Hydrogen bonds between water molecules are weaker than the hydrogen bonds between sodium and water or between chloride and water.
E. Hydrogen bonds between water molecules are weaker than the hydrogen bonds between sodium and water or between chloride and water.
222
A solute is
A. the dissolving agent of a solution.
B. usually water in living cells.
C. the liquid portion of a solution.
D. the substance that is dissolved in solution.
E. the dissolving agent of a solution which is usually oxygen in living cells.
D. the substance that is dissolved in solution.
223
A pharmaceutical company hires a chemist to analyze the purity of the water being used in its drug preparations. If the water is pure, the chemist would expect to find
```
A. H2O molecules and OH-ions.
B. H2O molecules, H+ ions, and OH- ions.
C. only molecules of H2O.
D. only H+ ions and OH- ions.
E. H2O molecules and H+ ions.
```
B. H2O molecules, H+ ions, and OH- ions.
224
Bases
A. either accept H+ ions from solutions or donate OH- ions to solutions.
B. accept OH- ions from solutions.
C. donate H+ ions to solutions.
D. donate OH- ions to solutions.
E. accept H+ ions from solutions.
A. either accept H+ ions from solutions or donate OH- ions to solutions.
225
A solution with a pH of 7 is
```
A. neutral.
B. strongly basic.
C. strongly acidic.
D. weakly basic.
E. weakly acidic.
```
A. neutral.
226
A solution with a pH of 1 is
```
A. strongly basic.
B. strongly acidic.
C. weakly basic.
D. neutral.
E. weakly acidic.
```
B. strongly acidic.
227
Which of the following statements about pH is/are true?
A. None of the choices are true.
B. pH is a measure of oxygen ion concentration.
C. An increase in hydrogen ion concentration means a decrease in pH scale units.
D. A single unit change on the pH scale is equivalent to a 1% change in hydrogen ion concentration.
E. pH stands for percent hydrogen.
C. An increase in hydrogen ion concentration means a decrease in pH scale units.
228
Household ammonia has a pH of 12; household bleach has a pH of 13. Which of the following statements is true?
A. Both of these substances are strong acids.
B. A solution that could buffer the bleach and ammonia would remove excess OH- ions.
C. The ammonia has 10 times as many OH- ions as the bleach.
D. The ammonia has 10 times as many H+ ions as the bleach.
E. The ammonia has 10 times as many OH- ions as the bleach and a solution that could buffer the bleach and ammonia would remove excess OH- ions.
D. The ammonia has 10 times as many H+ ions as the bleach.
229
A buffer
A. is a base that is used to offset overly acidic conditions in the body.
B. donates OH- ions when conditions become too acidic and accepts ions when conditions become too basic.
C. donates OH- ions when conditions become too basic and accepts ions when conditions become too acidic.
D. donates H+ ions when conditions become too basic and accepts ions when conditions become too acidic.
E. is an acid that is used to offset overly basic conditions in the body.
D. donates H+ ions when conditions become too basic and accepts ions when conditions become too acidic.
230
What can each of us do to decrease the production of acid precipitation? We can
A. drive more fuel-efficient automobiles.
B. decrease our consumption of coal-generated electricity.
C. encourage the use of alternative energy resources such as solar, wind, and geothermal energy.
D. whenever possible, walk or ride a bicycle instead of driving a car.
E. All of the choices are ways to decrease the production of acid precipitation.
E. All of the choices are ways to decrease the production of acid precipitation.
231
In the equation 2H2 + O2 = 2H2O , the H2 molecules are __________ and the H2O molecules are __________.
```
A. reactants . . . reactants
B. products . . . reactants
C. products . . . products
D. reactants . . . products
E. None of the choices are correct.
```
D. reactants . . . products
232
Which of the following is not a characteristic of chemical reactions?
A. The atoms of the reactants are exactly the same as the atoms of the products.
B. Chemical reactions involve the making and breaking of chemical bonds.
C. The reactants contain the same number of atoms as the products.
D. Although the atoms of a reaction's reactants and products are identical to each other, their molecular formulae differ.
E. Some chemical reactions create electrons; others destroy them.
E. Some chemical reactions create electrons; others destroy them.
233
When beta-carotene (C40H56) combines with oxygen (O2) and four hydrogens (4 H), two molecules of vitamin A are formed. Which of the following statements is/are true?
A. Each of the vitamin A molecules contains 20 carbon atoms.
B. Each of the vitamin A molecules contains 2 oxygen atoms.
C. Beta-carotene is one of the products of the reaction.
D. The vitamin A molecules are the reactants.
E. All of the statements are true.
A. Each of the vitamin A molecules contains 20 carbon atoms.
234
A mature ovary, specialized as a vessel that houses and protects seeds, is a
```
A. fruit.
B. ovule.
C. cotyledon.
D. None of the choices are correct.
E. seed.
```
A. fruit
235
A plant stem modified for nutrient storage is called a
```
A. runner.
B. rhizome.
C. bulb.
D. tuber.
E. taproot.
```
D. tuber.
236
A seed is a mature
```
A. pollen grain.
B. ovule.
C. fruit.
D. embryo.
E. ovary.
```
B. ovule.
237
A vascular cambium cell divides to produce an inner and an outer daughter cell. Which of the following choices represents a possible fate for these cells?
A. Both cells differentiate, the inner into phloem and the outer into cork.
B. Both cells differentiate, the inner into phloem and the outer into xylem.
C. The inner cell divides again, and the outer cell differentiates into cork.
D. The inner cell differentiates into xylem, and the outer cell divides again.
E. The inner cell differentiates into phloem, and the outer cell divides again.
D. The inner cell differentiates into xylem, and the outer cell divides again.
238
A woody plant goes through 5 years of drought followed by 5 years of good growing conditions. The xylem cells formed during the 5 good years will
A. be living, whereas those formed during the drought years will be dead.
B. conduct a higher ratio of sugar to water than those formed during the drought years.
C. form heartwood, as compared to the sapwood formed during the drought years.
D. form smaller growth rings than were formed during the drought years.
E. be larger in diameter than those formed during the drought years.
E. be larger in diameter than those formed during the drought years.
239
An aggregate fruit develops from
A. a single ovary.
B. several different plants.
C. several ovules from the same ovary.
D. several ovaries from separate flowers.
E. several ovaries from a single flower.
E. several ovaries from a single flower.
240
Bark consists of
A. functioning xylem, secondary phloem, cork cambium, and cork.
B. cork cambium and cork.
C. vascular cambium, secondary phloem, cork cambium, and cork.
D. secondary phloem, cork cambium, and cork.
E. cork only.
D. secondary phloem, cork cambium, and cork.
241
Dicot floral parts usually occur in multiples of
```
A. four or five.
B. five.
C. two.
D. three.
E. four.
```
A. four or five.
242
Dr. Esau discovered that plant viruses and sugars can be transported through plant tissues via
```
A. cellulose.
B. plasmodesmata.
C. the endoplasmic reticulum.
D. cell walls.
E. roots.
```
B. plasmodesmata.
243
Flowers bear seeds in protective chambers called
```
A. antheridia.
B. stamens.
C. cones.
D. sepals.
E. ovaries.
```
E. ovaries.
244
How does the sperm of an angiosperm reach the egg?
A. via raindrops or a dew film, through which the sperm swims to the egg from the pollen grain deposited on the stigma
B. usually via an insect, which perforates the ovary wall while probing for nectar
C. via the pollen tube that grows through the female gametophyte from the pollen grain deposited at the mouth of the ovary
D. via the pollen tube that grows through the carpel tissues from the pollen grain deposited on the stigma
E. usually via an insect, which places it in the ovary while probing for nectar
D. via the pollen tube that grows through the carpel tissues from the pollen grain deposited on the stigma
245
How many chromosomes are there in a corn egg cell nucleus as compared to a corn pollen cell nucleus?
A. half as many
B. half as many or the same number, depending on whether the pollen cell has divided to produce sperm or not
C. twice as many
D. twice as many or the same number, depending on which of the egg nuclei is considered
E. the same number
E. the same number
246
How many chromosomes are there in a corn embryo cell nucleus as compared to a corn endosperm cell nucleus?
```
A. twice as many
B. the same number
C. half as many
D. a third again as many
E. two-thirds as many
```
E. two-thirds as many
247
How many layers of vascular cambium will there be in the trunk of a 10-year-old tree?
```
A. nine
B. ten
C. five
D. two
E. one
```
E. one
248
In a flowering plant, eggs are produced by meiosis in the
```
A. stamens.
B. sepals.
C. stigma.
D. carpels.
E. petals.
```
D. carpels.
249
In a typical flower such as a magnolia or rose, the flower parts that play the main role in attracting the notice of animal pollinators are the
```
A. stigmas.
B. fruits.
C. stamens.
D. petals.
E. sepals.
```
D. petals.
250
Photosynthesis occurs in
```
A. the epidermis.
B. collenchyma.
C. parenchyma.
D. sclerenchyma.
E. vascular cambium.
```
C. parenchyma.
251
The cells that store starch in dicot roots are located between the
```
A. epidermis and the root hairs.
B. xylem and the phloem.
C. epidermis and the cortex.
D. epidermis and the endodermis.
E. xylem rays within the vascular cylinder.
```
D. epidermis and the endodermis.
252
The chief function of root hairs is to
A. protect roots from freezing temperatures.
B. increase the surface area for absorption of water and minerals.
C. provide a direct passageway from the soil to the vascular cylinder.
D. decrease the anchoring power of roots.
E. harbor symbiotic bacteria.
B. increase the surface area for absorption of water and minerals.
253
The "halves" of an individual peanut, which represent its cotyledons, are composed of
```
A. diploid maternal sporophyte cells.
B. diploid gametophyte cells.
C. haploid endosperm cells.
D. triploid endosperm cells.
E. diploid embryo sporophyte cells.
```
E. diploid embryo sporophyte cells.
254
The increase in girth (width) of trees occurs as a consequence of
```
A. growth in apical meristems.
B. secondary growth.
C. increase in width of vessel elements.
D. sexual reproduction.
E. primary growth.
```
B. secondary growth.
255
The laboratory technique that fuses two plant cells from species unable to reproduce in nature is called
```
A. cloning.
B. protoplast fusion.
C. monoculture propagation.
D. None of the choices are correct.
E. genetic engineering.
```
B. protoplast fusion.
256
The male organ of a flower is the
```
A. stamen.
B. carpel.
C. stigma.
D. style.
E. sepal.
```
A. stamen.
257
The most important factor responsible for pushing a growing root through the soil is
A. cell division in the apical meristem.
B. cell elongation behind the apical meristem.
C. branch root formation.
D. differentiation of xylem cells in the apical meristem.
E. cell elongation from the tip of the root cap.
B. cell elongation behind the apical meristem.
258
The rapid new shoot growth on a tree during the spring arises mainly from
```
A. cotyledons.
B. vascular cambium.
C. apical meristems.
D. quiescent centers.
E. procambium.
```
C. apical meristems.
259
The type of plant vascular tissue specialized to conduct sugars and other metabolic products is called
```
A. phloem.
B. parenchyma.
C. sclerenchyma.
D. xylem.
E. collenchyma.
```
A. phloem.
260
The vast majority of living plant species are
```
A. monocots.
B. gymnosperms.
C. dicots.
D. mosses.
E. cycads.
```
C. dicots.
261
The vegetative (i.e., nonreproducing) structures of flowering plants include
```
A. stems, flowers, and leaves.
B. stems, leaves, and fruits.
C. roots, stems, and seeds.
D. All of the choices are correct.
E. stems, leaves, and roots.
```
E. stems, leaves, and roots.
262
Which of the following substances allows some of a plant's vascular tissue to play a role analogous to that of an animal's skeleton?
```
A. lignin
B. sucrose
C. chlorophyll
D. starch
E. glucose
```
A. lignin
263
Which of the following types of plant cells functions in large part to limit a plant's loss of water vapor?
```
A. xylem
B. endodermal cells
C. guard cells
D. companion cells
E. root hairs
```
C. guard cells
264
Which of the following flower parts produces male gametophytes?
```
A. petals
B. stigmas
C. sepals
D. carpels
E. anthers
```
E. anthers
265
Which of the following structures is the first to emerge from a germinating dicot seed?
```
A. root
B. shoot hook
C. shoot sheath
D. cotyledons
E. root hair
```
A. root
266
Which of the following is a disadvantage of cloning as a propagation technique?
A. Cloning produces monocultures that can potentially be desolated by a single disease.
B. Cloning is time-consuming, with slow results.
C. It requires more space to clone plants than to use traditional seed propagation.
D. It is difficult to produce true-breeding crops by cloning.
E. Cloning is more expensive than growing from seeds.
A. Cloning produces monocultures that can potentially be desolated by a single disease.
267
Which one of the following is not a plant product for human use?
```
A. lumber
B. All of the choices are plant products for human use.
C. food
D. paper
E. some industrial chemicals
```
B. All of the choices are plant products for human use.
268
Which one of the following is a characteristic of monocots?
A. a fibrous root system
B. vascular bundles of nonwoody stems arranged in a ring
C. netlike venation
D. secondary growth
E. a flower with four or five petals
A. a fibrous root system
269
Which one of the following statements is not true?
A. Roots depend upon sugars produced in leaves.
B. The terminal bud in many plants produces hormones that inhibit growth in the axillary buds.
C. Stems and leaves depend on the water and minerals absorbed by the roots.
D. The part of the stem where a leaf attaches is called the internode.
E. The shoot system of a plant consists of the stems, leaves, and adaptations for reproduction.
D. The part of the stem where a leaf attaches is called the internode.
270
Which one of the following statements about germination is not true?
A. A germinating seed is fragile.
B. A hydrated seed expands, rupturing its seed coat.
C. In a germinating seed, the embryonic root extends deeper into the soil.
D. Germination usually begins when a seed takes up water.
E. The germination of a seed represents the beginning of life.
E. The germination of a seed represents the beginning of life.
271
Which type of vascular tissue cell in a plant is dead at maturity?
```
A. sclereids
B. sieve-tube cells
C. vessel elements
D. parenchyma cells
E. companion cells
```
C. vessel elements
272
While cleaning out the attic, you find a packet of seeds that your grandmother gathered from her garden. You plant them, and some come up. What was the condition of these germinating seeds while they were in the attic?
A. They were dormant.
B. They were in suspended animation.
C. They were turgid.
D. The endosperm cells were dead; the embryo cells were alive but inactive.
E. They were dead, but the embryo cells revived in response to water.
A. They were dormant.
273
Wholesale commercial production of many horticultural crops makes use of cloning techniques. Which of the following is an advantage of cloning over sexual propagation?
A. Plants produced by cloning grow more uniformly.
B. Cloned plants are healthier and less susceptible to disease.
C. Cloned plants are slower growing but have stronger stems.
D. Cloning is a simpler procedure and requires no special training.
E. Cloning provides more variation in flower color and size.
A. Plants produced by cloning grow more uniformly.
274
"Year after year, men cruising timber or hunting deer in the Blue Mountains of eastern Oregon had come back with the same story. Near the little hamlet of Kamela, they had often heard a faraway tinkling, a ghostly bell ringing . . . . Last week, slashing a right-of-way for a power line from Bonneville Dam, lumberjacks brought down a ponderosa pine and tied by a shriveled leather thong, high in the treetop was the answer to the mystery of Kamela: a bronze cattle bell, inscribed with the date 1878 . . . . The people of Kamela guessed that a pioneer had tied it to a sapling that grew into a towering pine." (Time) Which of the following is the best appraisal of the concluding sentence in this report?
A. logical, because a tree elongates from the ground up
B. logical, because this particular tree could have attained great height since 1878
C. There is no basis for appraising the concluding sentence of the report.
D. illogical, because elongation occurs only in the regions of meristematic cells
E. illogical, because no one knows with certainty when the bell was tied to the sapling
D. illogical, because elongation occurs only in the regions of meristematic cells
275
Many of the enzymes that control a firefly's ability to produce light energy from chemical energy are located
```
A. in membranes.
B. within mitochondria.
C. in the nucleus.
D. within chloroplasts.
E. outside of cells.
```
A. in membranes.
276
Kinetic energy differs from chemical energy in that
A. kinetic energy can be converted into various forms of energy, whereas chemical energy can only be converted into heat.
B. kinetic energy depends on the movement of atoms, whereas chemical energy depends on the movement of molecules.
C. kinetic energy is stored energy that has the potential to do work, and chemical energy is the energy of movement.
D. chemical energy is a particular form of kinetic energy.
E. kinetic energy is the energy of a moving object, whereas chemical energy is the potential energy of molecules.
E. kinetic energy is the energy of a moving object, whereas chemical energy is the potential energy of molecules.
277
Glucose molecules provide energy to power the swimming motion of sperm. In this example, the sperm are changing
A. chemical energy into kinetic energy.
B. kinetic energy into chemical energy.
C. None of the choices are correct.
D. chemical energy into potential energy.
E. kinetic energy into potential energy.
A. chemical energy into kinetic energy
278
Which one of the following is not true?
A. The collection of matter under study is called the system.
B. An open system exchanges both energy and matter with its surroundings.
C. Thermodynamics is the study of energy transformations that occur in a collection of matter.
D. An automobile engine is an example of a closed system.
E. A single cell or the planet Earth could be a thermodynamic system.
D. An automobile engine is an example of a closed system.
279
According to __________, energy cannot be created or destroyed.
```
A. the second law of thermodynamics
B. the first law of thermodynamics
C. the third law of thermodynamics
D. Einstein's law of relativity
E. Aristotle's first principle
```
B. the first law of thermodynamics
280
A steer must eat at least 100 pounds of grain to gain less than 10 pounds of muscle tissue. This illustrates
A. that some energy is destroyed in every energy conversion.
B. the first law of thermodynamics.
C. None of the choices are correct.
D. the second law of thermodynamics.
E. that energy transformations are typically 100% efficient.
D. the second law of thermodynamics.
281
Which of the following energy transfers is/are possible in living systems?
```
A. potential energy to kinetic energy
B. chemical energy to kinetic energy
C. light energy to chemical energy
D. light energy to potential energy
E. All of the choices are correct.
```
E. All of the choices are correct.
282
Living systems
A. decrease their entropy while increasing the entropy of the universe.
B. violate the first law of thermodynamics.
C. None of the choices are correct.
D. violate the second law of thermodynamics.
E. are examples of a closed system.
A. decrease their entropy while increasing the entropy of the universe.
283
Which one of the following processes is endergonic?
A. the synthesis of glucose from carbon dioxide and water
B. the release of heat from the breakdown of glucose
C. the breakdown of glucose to power ATP formation
D. the burning of wood
E. cellular respiration
A. the synthesis of glucose from carbon dioxide and water
284
What is the basic difference between exergonic and endergonic reactions?
A. Exergonic reactions involve ionic bonds; endergonic reactions involve covalent bonds.
B. Exergonic reactions release energy; endergonic reactions absorb it.
C. Exergonic reactions involve the formation of bonds; endergonic reactions involve the breaking of bonds.
D. Exergonic reactions involve the breaking of bonds; endergonic reactions involve the formation of bonds.
E. In exergonic reactions, the reactants have less chemical energy than the products; in endergonic reactions, the opposite is true.
B. Exergonic reactions release energy; endergonic reactions absorb it.
285
Which one of the following statements concerning energy is not true?
A. A gasoline engine converts chemical energy into kinetic energy.
B. Energy transformations in cells are accompanied by the release of heat energy.
C. During photosynthesis, plants convert kinetic energy into chemical energy.
D. Fireflies are able to take potential energy in the form of food and convert that energy into kinetic energy in the form of heat and light.
E. Living systems convert heat energy into chemical energy to reduce entropy.
E. Living systems convert heat energy into chemical energy to reduce entropy.
286
The transfer of a phosphate group to a molecule or compound is called
```
A. hydrogenation.
B. carboxylation.
C. phosphorylation.
D. hydrogen bonding.
E. ionization.
```
C. phosphorylation
287
Anything that prevents ATP formation will most likely
A. result in the conversion of kinetic energy to potential energy.
B. have no effect on the cell.
C. force the cell to rely on lipids for energy.
D. result in cell death.
E. force the cell to rely on ADP for energy.
D. result in cell death.
288
When a cell uses chemical energy to perform work, it couples a(n) __________ reaction with a(n) __________ reaction.
```
A. endergonic . . . exergonic
B. exergonic . . . spontaneous
C. exergonic . . . endergonic
D. endergonic . . . spontaneous
E. spontaneous . . . exergonic
```
C. exergonic . . . endergonic
289
Which one of the following is true about the ATP molecule?
A. None of the choices are correct.
B. It contains the six-carbon sugar hexose.
C. It contains two phosphate groups.
D. It contains a nitrogenous base molecule called adenine.
E. Extremely stable bonds link the second and third phosphate groups.
D. It contains a nitrogenous base molecule called adenine.
290
ATP can be used as the cell's energy currency because
A. endergonic reactions can be fueled by coupling them with the hydrolysis of high-energy phosphate bonds in ATP.
B. ATP is the most energy-rich small molecule in the cell.
C. the regeneration of ATP from ADP can be fueled by coupling it with endergonic reactions.
D. None of the choices are correct.
E. endergonic reactions can be fueled by coupling them with the formation of ATP from ADP.
A. endergonic reactions can be fueled by coupling them with the hydrolysis of high-energy phosphate bonds in ATP.
291
An energy barrier
A. is the amount of energy that must be produced by the reactants to start a chemical reaction.
B. is lower than the energy of activation of a reaction.
C. prevents the spontaneous decomposition of ATP in the cell.
D. None of the choices are correct.
E. is higher than the energy of activation of a reaction.
C. prevents the spontaneous decomposition of ATP in the cell
292
Most of a cell's enzymes are
```
A. proteins.
B. carbohydrates.
C. nucleic acids.
D. lipids.
E. amino acids.
```
A. proteins.
293
When an enzyme catalyzes a reaction
A. it raises the activation energy of the reaction.
B. None of the choices are correct.
C. it acts as a reactant.
D. it lowers the activation energy of the reaction.
E. it becomes a product.
D. it lowers the activation energy of the reaction.
294
The active site of an enzyme is
A. None of the choices are correct.
B. the region of a product that detaches from the enzyme.
C. the region of a substrate that is
changed by an enzyme.
D. the region of an enzyme that attaches to a substrate.
E. the highly changeable portion of an enzyme that adapts to fit the substrates of various reactions.
D. the region of an enzyme that attaches to a substrate.
295
Which one of the following is not true?
A. Enzymes are used up in chemical reactions.
B. An enzyme binds to its substrate at the enzyme's active site.
C. An enzyme's function depends on its three-dimensional shape.
D. Enzymes emerge unchanged from the reactions they catalyze.
E. Enzymes are very specific for certain substrates.
A. Enzymes are used up in chemical reactions.
296
Which one of the following is true?
A. Enzymes are inorganic.
B. Enzymes are the reactants in a chemical reaction.
C. An enzyme's function is unaffected by changes in pH.
D. Enzymes catalyze specific reactions.
E. An enzyme's function is dependent on the presence of protein helpers known as cofactors.
D. Enzymes catalyze specific reactions.
297
Which of the following substances could be a cofactor?
```
A. a ribosome
B. a protein
C. None of the choices are correct.
D. a zinc atom
E. a polypeptide
```
D. a zinc atom
298
A child is brought to the hospital with a fever of 107F. Doctors immediately order an ice bath to lower the child's temperature. Which explanation offers the most logical reason for this action?
A. Elevated body temperatures cause molecules to vibrate more quickly and prevent enzymes from easily attaching to reactants. This would slow vital body reactions.
B. Elevated body temperatures easily break the covalent bonds linking biologically important molecules. This will cause a general breakdown of cell structures.
C. Elevated body temperature will increase reaction rates in the child's cells and overload the limited number of enzymes found in the cell.
D. Elevated body temperatures will increase the energy of activation needed to start various chemical reactions in the body. This will interfere with the ability of enzymes to catalyze vital chemical reactions.
E. Elevated body temperatures may denature enzymes. This would interfere with the cell's abilities to catalyze various reactions.
E. Elevated body temperatures may denature enzymes. This would interfere with the cell's abilities to catalyze various reactions.
299
Heating inactivates enzymes by
A. None of the choices are correct.
B. removing phosphate groups from the enzyme.
C. causing enzyme molecules to stick together.
D. breaking the covalent bonds that hold the molecule together.
E. changing the enzyme's three-dimensional shape.
E. changing the enzyme's three-dimensional shape.
300
Which of the following is a coenzyme?
```
A. hydrogen ions
B. zinc
C. iodine
D. iron
E. vitamin B6
```
E. vitamin B6
301
Which of the following can affect the rate of an enzyme-catalyzed reaction?
```
A. noncompetitive inhibitors
B. temperature
C. pH
D. All of the choices are correct.
E. competitive inhibitors
```
D. All of the choices are correct.
302
Inhibition of an enzyme is irreversible when
A. a noncompetitive inhibitor is involved.
B. covalent bonds form between inhibitor and enzyme.
C. the shape of the enzyme is changed.
D. None of the choices are correct.
E. a competitive inhibitor is involved.
B. covalent bonds form between inhibitor and enzyme.
303
How does inhibition of an enzyme-catalyzed reaction by a competitive inhibitor differ from inhibition by a noncompetitive inhibitor?
A. Competitive inhibitors change the enzyme's tertiary structure; noncompetitive inhibitors cause polypeptide subunits to dissociate.
B. Competitive inhibitors are inorganic substances such as metal ions; noncompetitive inhibitors are vitamins or vitamin derivatives.
C. Competitive inhibitors bind to the active site of the enzyme; noncompetitive inhibitors bind to a different site.
D. Competitive inhibitors bind to the enzyme reversibly; noncompetitive inhibitors bind to it irreversibly.
E. Competitive inhibitors interfere with the enzyme; noncompetitive inhibitors interfere with the reactants.
C. Competitive inhibitors bind to the active site of the enzyme; noncompetitive inhibitors bind to a different site.
304
Bacterial production of the enzymes needed for the synthesis of the amino acid tryptophan declines with increasing levels of tryptophan and increases as tryptophan levels decline. This is an example of
```
A. negative feedback.
B. noncompetitive inhibition.
C. irreversible inhibition.
D. competitive inhibition.
E. positive feedback.
```
A. negative feedback.
305
A medical research team is concerned about the outbreak of a new disease in humans. The bacteria that cause the disease resemble bacteria that cause a similar disease in cattle. The bovine disease is treated with a drug that inhibits a bacterial enzyme crucial to bacterial cell division. As the researchers prepare to test the drug in humans, they will
A. be concerned about its safety; since all living cells contain the same enzymes, the drug is likely to cause cell damage; the question is whether the damage is too large to be tolerated.
B. be fairly confident about its safety; bacterial enzymes are all very different from human enzymes, so the drug should only affect the bacteria.
C. be uncertain about its safety; human cells contain some enzymes that are very similar to those found in bacterial cells; the drug may inhibit these enzymes and damage the human cells.
D. be fairly confident about its safety; although bacteria produce all of the same enzymes as human cells, the small size of bacteria make them more susceptible to damage.
E. None of the choices are correct.
C. be uncertain about its safety; human cells contain some enzymes that are very similar to those found in bacterial cells; the drug may inhibit these enzymes and damage the human cells.
306
Malathion and tetracycline are both enzyme inhibitors. Malathion is used to kill insects; tetracycline to kill bacteria. Malathion is more toxic to human cells than is tetracycline. Which of the following explanations for the difference in toxicity to human cells would be reasonable?
A. Malathion binds to its enzyme reversibly; tetracycline binds to its enzyme irreversibly.
B. None of the choices are correct.
C. Malathion is a competitive inhibitor; tetracycline is a noncompetitive inhibitor.
D. Human cells contain the enzymes inhibited by both compounds, but the enzyme inhibited by malathion is not metabolically crucial.
E. Human cells do not contain the enzymes inhibited by malathion or tetracycline.
D. Human cells contain the enzymes inhibited by both compounds, but the enzyme inhibited by malathion is not metabolically crucial.
307
Where are eukaryotic cell enzymes typically located?
A. inside organelles
B. in cell membranes and inside organelles
C. outside of the cell
D. within the cytoskeleton
E. in cell membranes
B. in cell membranes and inside organelles
308
Plasma membranes are selectively permeable. This means that
A. cholesterol cannot enter the cell.
B. glucose cannot enter the cell.
C. plasma membranes must be very thick.
D. anything can pass into or out of a cell.
E. the plasma membrane regulates the passage of material into and out of the cell.
E. the plasma membrane regulates the passage of material into and out of the cell
309
Which one of the following is not a function of the plasma membrane? The plasma membrane
A. forms a selective barrier around the cell.
B. plays a role in signal transduction.
C. is the control center of the cell.
D. is involved in self-recognition.
E. has receptors for chemical messages.
C. is the control center of the cell.
310
Small, nonpolar, hydrophobic molecules such as fatty acids
A. very slowly diffuse through a membrane's lipid bilayer.
B. easily pass through a membrane's lipid bilayer.
C. require transport proteins to pass through a membrane's lipid bilayer.
D. usually enter the cell via endocytosis.
E. are actively transported across cell membranes.
B. easily pass through a membrane's lipid bilayer.
311
Membrane phospholipids
A. often have "kinks" in their tails caused by the presence of a single rather than a double bond between carbons.
B. have hydrophilic tails that face outward and are exposed to water.
C. None of the choices are correct.
D. remain fluid because they are tightly packed against one another.
E. have hydrophobic heads that face the center of the membrane and are shielded from water.
C. None of the choices are correct.
312
Which one of the following substances would have the most trouble crossing a biological membrane by diffusing through the lipid bilayer?
A. O2
B. H2O
C. CO2
D. Na+
D. Na+
313
The fluid mosaic model describes the plasma membrane as consisting of
A. carbohydrates, proteins, and phospholipids that can drift in the membrane.
B. individual proteins and phospholipids that can drift in a phospholipid bilayer.
C. two layers of phospholipids with protein sandwiched between them.
D. a protein bilayer with embedded phospholipids.
E. a phospholipid bilayer with embedded carbohydrates
B. individual proteins and phospholipids that can drift in a phospholipid bilayer.
314
The cholesterol associated with cell membranes
A. is attached to membrane proteins and extends into the watery environment surrounding the cell.
B. helps to stabilize the cell membrane at body temperature.
C. makes the cell membrane fluid at room temperature.
D. is an abnormality resulting from a diet high in cholesterol.
E. None of the choices are correct.
B. helps to stabilize the cell membrane at body temperature.
315
A major function of glycoproteins and glycolipids in the cell membrane is to
A. glue cells together to form tissues.
B. help the cell retain its shape.
C. attach the cell membrane to the cytoskeleton.
D. allow the cells of an embryo to sort themselves into tissues and organs.
E. help the cell resist swelling.
D. allow the cells of an embryo to sort themselves into tissues and organs.
316
When physicians perform an organ transplant, they choose a donor whose tissues match those of the recipient as closely as possible. Which of the following cell components are being matched?
```
A. plasma membrane cholesterols
B. cell-surface carbohydrates
C. plasma membrane proteins
D. cytoskeletal elements
E. plasma membrane phospholipids
```
B. cell-surface carbohydrates
317
Most of the functions of a cell membrane are performed by
```
A. proteins.
B. glycolipids.
C. cholesterol.
D. phospholipids.
E. nucleotides.
```
A. proteins.
318
Which one of the following is not a function of membrane proteins? Membrane proteins
A. form junctions between cells.
B. serve as enzymes.
C. attach the membrane to the cytoskeleton.
D. provide cellular identification tags.
E. All of the choices are membrane protein functions.
E. All of the choices are membrane protein functions.
319
Relaying a message from a membrane receptor to a molecule that performs a specific function within a cell is called
```
A. inhibition.
B. selective permeability.
C. signal transduction.
D. self-recognition.
E. competition.
```
C. signal transduction.
320
Which of the following is not a true statement about diffusion? Diffusion
A. is a result of the kinetic energy of atoms and molecules.
B. requires no input of energy into the system.
C. is driven by entropy.
D. proceeds until equilibrium is reached.
E. occurs when particles spread from areas where they are less concentrated to areas where they are more concentrated.
E. occurs when particles spread from areas where they are less concentrated to areas where they are more concentrated.
321
Diffusion does not require the cell to expend ATP. Therefore, diffusion is considered a type of
```
A. endocytosis.
B. passive transport.
C. phagocytosis.
D. exocytosis.
E. active transport.
```
B. passive transport.
322
When two aqueous solutions that differ in solute concentration are placed on either side of a semipermeable membrane, and osmosis is allowed to take place, the water will
A. exhibit a net movement to the side with lower water concentration.
B. exhibit an equal movement in both directions across the membrane.
C. exhibit a net movement to the side with higher water concentration.
D. not cross the membrane.
E. exhibit a net movement to the side with lower solute concentration.
A. exhibit a net movement to the side with lower water concentration.
323
In lab, you use a special balloon that is permeable to water but not sucrose to make an "artificial cell." The balloon is filled with a solution of 20% sucrose and 80% water and is immersed in a beaker containing a solution of 40% sucrose and 60% water. Which of the following will occur?
```
A. Sucrose will enter the balloon.
B. Sucrose will leave the balloon.
C. Water will leave the balloon.
D. None of the choices will occur.
E. Water will enter the balloon.
```
C. Water will leave the balloon.
324
In lab, you use a special balloon that is permeable to water but not sucrose to make an "artificial cell." The balloon is filled with a solution of 20% sucrose and 80% water and is immersed in a beaker containing a solution of 40% sucrose and 60% water. The solution in the balloon is __________ relative to the solution in the beaker.
```
A. hydrophilic
B. hypotonic
C. hypertonic
D. isotonic
E. hydrophobic
```
B. hypotonic
325
A cell that neither gains nor loses water when it is immersed in a solution is
```
A. metabolically inactive.
B. hypertonic to its environment.
C. hypotonic to its environment.
D. isotonic to its environment.
E. dead.
```
D. isotonic to its environment.
326
Some protozoans have special organelles called contractile vacuoles that continually eliminate excess water from the cell. The presence of these organelles tells you that the environment
```
A. is hypotonic to the protozoan.
B. is hypertonic to the protozoan.
C. None of the choices are correct.
D. contains a higher concentration of solutes than the protozoan.
E. is isotonic to the protozoan.
```
A. is hypotonic to the protozoan
327
Osmosis can be defined as
```
A. the diffusion of a solute.
B. the diffusion of nonpolar molecules.
C. the diffusion of water.
D. active transport.
E. endocytosis.
```
C. the diffusion of water.
328
If placed in tap water, an animal cell will undergo lysis, whereas a plant cell will not. What accounts for this difference?
A. the relative impermeability of the plant cell membrane to water
B. the relative impermeability of the plant cell wall to water
C. the relative inelasticity and strength of the plant cell wall
D. expulsion of water by the plant cell's central vacuole
E. the fact that plant cells are isotonic to tap water
C. the relative inelasticity and strength of the plant cell wall
329
A plant cell in a hypotonic solution
```
A. is flaccid.
B. is turgid.
C. wilts.
D. shrivels.
E. lyses.
```
B. is turgid.
330
You are adrift in the Atlantic Ocean, and, being thirsty, drink the surrounding seawater. As a result,
A. your cells lyse, due to the excessive intake of salt.
B. your cells become turgid.
C. None of the choices are correct.
D. you quench your thirst.
E. you dehydrate yourself.
E. you dehydrate yourself.
331
The organ that plays a major role in osmoregulation in humans is the
```
A. pancreas.
B. gallbladder.
C. spleen.
D. heart.
E. kidney.
```
E. kidney.
332
Facilitated diffusion across a biological membrane requires __________ and moves a substance __________ its concentration gradient.
A. energy . . . down
B. energy and transport proteins . . . against
C. energy and transport proteins . . . down
D. transport proteins . . . against
E. transport proteins . . . down
E. transport proteins . . . down
333
The molecules responsible for membrane transport are
```
A. proteins.
B. carbohydrates.
C. steroids.
D. ATP.
E. phospholipids.
```
A. proteins.
334
Which one of the following processes could result in the net movement of a substance into a cell, if the substance is more concentrated in the cell than in the surroundings?
```
A. facilitated diffusion
B. osmosis
C. active transport
D. diffusion
E. None of the choices are correct.
```
C. active transport
335
Which one of the following is a typical feature of an ATP-driven active transport mechanism?
A. The transport protein must cross to the correct side of the membrane before the solute can bind to it.
B. None of the choices are correct.
C. The transport protein catalyzes the conversion of ADP to ATP.
D. The solute must be phosphorylated before it can bind to the transport protein.
E. The transport protein is irreversibly phosphorylated as transport takes place.
B. None of the choices are correct.
336
Active transport
A. can move solutes up a concentration gradient.
B. uses ATP as an energy source.
C. requires the cell to expend energy.
D. can involve the coupled passage of solutes.
E. All of the choices are correct.
E. All of the choices are correct.
337
Certain cells that line the stomach synthesize a digestive enzyme and secrete it into the stomach. This enzyme is a protein. Which of the following processes could be responsible for its secretion?
```
A. passive transport
B. exocytosis
C. pinocytosis
D. endocytosis
E. diffusion
```
B. exocytosis
338
Which of the following pieces of evidence would prove that a substance enters a cell by active rather than passive transport?
A. The substance enters the cell when its concentration is higher outside the cell than inside.
B. None of the choices are correct.
C. The breakdown of ATP is needed for transport to occur.
D. All of the choices are correct.
E. The substance is moved across the cell membrane by a carrier protein.
C. The breakdown of ATP is needed for transport to occur.
339
The act of a white blood cell engulfing a bacterium is
```
A. receptor-mediated endocytosis.
B. osmosis.
C. pinocytosis.
D. phagocytosis.
E. diffusion.
```
D. phagocytosis.
340
Phagocytosis is to eating as pinocytosis is to
```
A. lysis.
B. chewing.
C. osmosis.
D. hydrolysis.
E. drinking.
```
E. drinking.
341
Cells acquire LDLs by
```
A. diffusion.
B. receptor-mediated endocytosis.
C. phagocytosis.
D. pinocytosis.
E. osmosis.
```
B. receptor-mediated endocytosis.
342
An inherited lack (or shortage) of functional LDL receptors causes
```
A. cystic fibrosis.
B. hypercholesterolemia.
C. hyperbilirubinemia.
D. type I diabetes.
E. Marfan's syndrome.
```
B. hypercholesterolemia.
343
The ultimate source of nearly all energy available to life on Earth is
```
A. electricity.
B. photosynthesis.
C. cellular respiration.
D. wind.
E. sunlight.
```
E. sunlight.
344
Ultimately, nearly all animals are dependent on __________ as their source of energy.
```
A. heat
B. electricity
C. wind
D. photosynthesis
E. cellular respiration
```
D. photosynthesis
345
Compared to slow-twitch fibers, fast-twitch muscle fibers
```
A. don't require as much oxygen.
B. have fewer mitochondria.
C. are thicker.
D. All of the above are correct.
E. have less myoglobin.
```
D. All of the above are correct.
346
Which one of the following statements is not true?
A. The proportion of fast- and slow-twitch fibers is genetically determined.
B. Training usually converts one type of muscle fiber into another.
C. Fast-twitch fibers rely upon ATP produced anaerobically.
D. The percentage of each fiber type varies from person to person.
E. All human muscles contain fast- and slow-twitch muscle fibers.
B. Training usually converts one type of muscle fiber into another.
347
The term anaerobic means
```
A. without ATP.
B. without CO2.
C. without bacteria.
D. without O2.
E. with O2.
```
D. without O2.
348
Respiration __________, and cellular respiration __________.
A. uses glucose . . . produces glucose
B. is gas exchange . . . produces ATP
C. produces ATP . . . is gas exchange
D. produces glucose . . . is gas exchange
E. produces glucose . . . produces oxygen
B. is gas exchange . . . produces ATP
349
Which of the following are products of cellular respiration?
```
A. energy and carbon dioxide
B. glucose and carbon dioxide
C. oxygen and carbon dioxide
D. oxygen and energy
E. oxygen and glucose
```
A. energy and carbon dioxide
350
Which of the following statements is/are true about the energy yields from cellular respiration?
A. The heat produced during cellular respiration is only a tiny fraction of the chemical energy available in a glucose molecule.
B. Cellular respiration converts the kinetic energy of glucose into chemical energy.
C. All of the choices are true.
D. Cellular respiration converts all of the energy in glucose into high-energy ATP bonds.
E. Cellular respiration is more efficient at harnessing energy from glucose than car engines are at harnessing energy from gasoline.
E. Cellular respiration is more efficient at harnessing energy from glucose than car engines are at harnessing energy from gasoline.
351
Which one of the following statements is not true? Aerobic cellular respiration
A. results in an increase in the entropy of the universe.
B. is less efficient than an automobile engine.
C. can "burn" many organic molecules other than glucose.
D. is consistent with the second law of thermodynamics.
E. is consistent with the first law of thermodynamics.
B. is less efficient than an automobile engine.
352
Humans use the calories they obtain from __________ as their source of energy.
```
A. minerals
B. sunlight
C. food
D. carbon dioxide
E. water
```
C. food
353
Humans use about __________ of their daily calories for involuntary life-sustaining activities such as digestion, circulation, and breathing.
```
A. 90%
B. 50%
C. 75%
D. 10%
E. 25%
```
C. 75%
354
The overall equation for the cellular respiration of glucose is
A. C5H12O6 + 6 O2 ? 5 CO2 + 6 H2O + energy.
B. 5 CO2 + 6 H2O ? C5H12O6 + 6 O2 + energy.
C. None of the choices are correct.
D. C6H12O12 + 3 O2 ? 6 CO2 + 6 H2O + energy.
E. C6H12O6 + 6 O2 ? 6 CO2 + 6 H2O + energy.
E. C6H12O6 + 6 O2 ? 6 CO2 + 6 H2O + energy.
355
During cellular respiration, the energy in glucose
```
A. is released by endergonic reactions.
B. is released all at once.
C. is carried by electrons.
D. None of the choices are correct.
E. is used to manufacture glucose by exergonic reactions.
```
C. is carried by electrons.
356
During redox reactions
A. protons from one molecule replace the electrons lost from another molecule.
B. None of the choices are correct.
C. a substance that gains electrons is said to be oxidized.
D. electrons are lost from one substance and added to another substance.
E. the loss of electrons from one substance is called reduction.
D. electrons are lost from one substance and added to another substance.
357
Oxidation is the __________, and reduction is the __________.
A. gain of electrons . . . loss of electrons
B. loss of electrons . . . gain of electrons
C. gain of oxygen . . . loss of oxygen
D. loss of oxygen . . . gain of oxygen
E. gain of protons . . . loss of protons
B. loss of electrons . . . gain of electrons
358
A redox reaction is an example of
```
A. hydrolysis.
B. condensation.
C. peptide bond formation.
D. a coupled reaction.
E. dehydration synthesis.
```
D. a coupled reaction.
359
In biological systems, important enzymes involved in the regulation of redox reactions are
```
A. NAD+s.
B. NADHs.
C. dehydrogenases.
D. ATPs.
E. H+s.
```
C. dehydrogenases.
360
During cellular respiration, NADH
A. is reduced to form NAD+.
B. None of the choices are correct.
C. is converted directly into ATP.
D. is converted to NAD+ by an enzyme called a dehydrogenase.
E. is involved in an exergonic reaction when it gives up electrons to other molecules.
E. is involved in an exergonic reaction when it gives up electrons to other molecules.
361
During cellular respiration, electrons move through a series of electron-carrier molecules. Which of the following is a true statement about this process?
A. The electrons release large amounts of energy each time they are transferred from one carrier to another.
B. The electrons move from carriers that have more affinity for them to carriers that have less affinity for them.
C. Molecular oxygen is eventually oxidized by the electrons to form water.
D. The carrier molecules are found in the cytoplasm of eukaryotic and prokaryotic cells.
E. None of the statements are true.
E. None of the statements are true.
362
The functioning of an electron transport chain is analogous to
A. a person climbing a flight of stairs one step at a time.
B. a person leaping from the top to the bottom of a flight of stairs in one jump.
C. a Slinky toy going down a flight of stairs.
D. playing Ping-Pong.
E. a canoe going over a waterfall.
C. a Slinky toy going down a flight of stairs.
363
Unlike those of eukaryotes, the electron transport chains of prokaryotes are located in the
```
A. plasma membrane.
B. central vacuole.
C. ER.
D. Golgi apparatus.
E. nuclear membrane.
```
A. plasma membrane.
364
Which of the following statements differentiates substrate-level phosphorylation from chemiosmotic phosphorylation?
A. Substrate-level phosphorylation is independent of the electron transport chain.
B. In substrate-level phosphorylation, a phosphate group is transferred directly from a metabolic intermediate to ADP.
C. Substrate-level phosphorylation can occur outside the mitochondrion.
D. Substrate-level phosphorylation can occur in the absence of oxygen.
E. All of the statements are correct.
A. Substrate-level phosphorylation is independent of the electron transport chain
365
Which one of the following is the correct sequence of stages in cellular respiration?
A. electron transport chain and chemiosmosis, glycolysis, Krebs cycle
B. Krebs cycle, glycolysis, electron transport chain and chemiosmosis
C. glycolysis, Krebs cycle, electron transport chain and chemiosmosis
D. electron transport chain and chemiosmosis, Krebs cycle, glycolysis
E. Krebs cycle, electron transport chain and chemiosmosis, glycolysis
C. glycolysis, Krebs cycle, electron transport chain and chemiosmosis
366
A drug is tested in the laboratory and is found to create holes in both mitochondrial membranes. Scientists suspect that the drug will be harmful to human cells because it will inhibit
```
A. the formation of alcohol.
B. the Krebs cycle.
C. glycolysis.
D. the Krebs cycle and chemiosmosis.
E. chemiosmosis.
```
D. the Krebs cycle and chemiosmosis.
367
During which of the following phases of cellular respiration does substrate-level phosphorylation take place?
```
A. glycolysis and the Krebs cycle
B. chemiosmosis
C. the Krebs cycle
D. "grooming" of pyruvic acid
E. glycolysis
```
A. glycolysis and the Krebs cycle
368
Which of the following metabolic pathways is common to both aerobic and anaerobic processes of sugar breakdown?
A. conversion of pyruvic acid to lactic acid
B. Krebs cycle
C. conversion of pyruvic acid to acetyl CoA
D. electron transport chain
E. None of the choices are correct.
E. None of the choices are correct.
369
Which of the following is a result of glycolysis?
A. production of CO2
B. conversion of glucose to two three-carbon compounds
C. reduction of FAD to FADH2
D. a net loss of two ATPs per glucose molecule
E. conversion of NADH to NAD+
B. conversion of glucose to two three-carbon compounds
370
A culture of bacteria growing aerobically is fed glucose containing radioactive carbon and is then examined. As the bacteria metabolize the glucose, radioactivity will appear first in
```
A. glucose 6-phosphate.
B. pyruvic acid.
C. NADH.
D. carbon dioxide.
E. ATP.
```
A. glucose 6-phosphate.
371
The end products of glycolysis include
```
A. FADH.
B. NADH.
C. O2.
D. citric acid.
E. acetyl CoA.
```
B. NADH
372
Glycolysis
```
A. does not occur in bacterial cells.
B. does not occur in animal cells.
C. does not occur in plant cells.
D. does not occur in yeast cells.
E. takes place in virtually all cells.
```
E. takes place in virtually all cells.
373
Pyruvic acid is considered a(n) __________ aerobic cellular respiration.
```
A. end product of
B. enzyme in
C. cofactor in
D. intermediate in
E. source of O2 for
```
D. intermediate in
374
During cellular respiration, glucose is converted into two pyruvic acid molecules. These molecules
A. together contain less chemical energy than was found in the original glucose molecule.
B. are oxidized.
C. each lose a carbon atom, which is released as CO2.
D. are each converted into a two-carbon molecule joined to a coenzyme A molecule.
E. All of the choices are correct.
E. All of the choices are correct.
375
The bridge between glycolysis and the Krebs cycle is
A. the oxidation of FADH2.
B. the production of alcohol.
C. the conversion of pyruvic acid to acetyl CoA.
D. the oxidation of NADH.
E. the conversion of ADP to ATP.
C. the conversion of pyruvic acid to acetyl CoA
376
The enzymes of the Krebs cycle are located in the
```
A. inner mitochondrial membrane.
B. mitochondrial matrix.
C. cytoplasm.
D. outer mitochondrial membrane.
E. intermembrane space of the mitochondrion.
```
B. mitochondrial matrix
377
The end products of the Krebs cycle include all of the following except
```
A. NADH.
B. FADH2.
C. pyruvic acid.
D. ATP.
E. CO2.
```
C. pyruvic acid.
378
A culture of bacteria growing aerobically is fed glucose containing radioactive carbon and is then examined. During the Krebs cycle, radioactivity would first appear in
```
A. NADH.
B. FADH2.
C. oxaloacetic acid.
D. CoA.
E. citric acid.
```
E. citric acid.
379
At the end of the Krebs cycle, most of the energy remaining from the original glucose is stored in
```
A. pyruvic acid.
B. ATP.
C. NADH.
D. FADH2.
E. CO2.
```
C. NADH
380
During chemiosmosis
A. ATP is synthesized when H+ ions move through a protein port provided by ATP synthase.
B. energy is generated because H+ ions move freely across mitochondrial membranes.
C. energy is generated by coupling exergonic reactions with other exergonic reactions.
D. H+ ions serve as the final electron acceptor.
E. a concentration gradient is generated when large numbers of H+ ions are passively transported from the matrix of the mitochondrion to the mitochondrion's intermembrane space.
A. ATP is synthesized when H+ ions move through a protein port provided by ATP synthase.
381
A mutant protist is found in which some mitochondria lack an inner mitochondrial membrane. Which of the following pathways would be completely disrupted in these mitochondria?
```
A. chemiosmosis
B. the Krebs cycle
C. alcoholic fermentation
D. the Krebs cycle and glycolysis
E. glycolysis
```
A. chemiosmosis
382
In the respiratory electron transport chain, electrons are passed from one electron transport molecule to another and are finally accepted by
```
A. a molecule of carbon dioxide.
B. ADP.
C. an oxygen atom.
D. a molecule of water.
E. ATP.
```
C. an oxygen atom.
383
A child is born with a rare disease in which mitochondria are missing from skeletal muscle cells. Physicians find that the muscles function. Not surprisingly, they also find that
A. the muscles contain large amounts of carbon dioxide following even mild physical exercise.
B. the muscle cells cannot split glucose to pyruvic acid.
C. the muscles require extremely high levels of oxygen to function.
D. the muscles require extremely large amounts of carbon dioxide to function.
E. the muscles contain large amounts of lactic acid following even mild physical exercise.
E. the muscles contain large amounts of lactic acid following even mild physical exercise.
384
Which of the following is not true of the inner mitochondrial membrane?
A. Electron carriers are associated with it.
B. An H+ gradient exists across it.
C. It plays a role in the production of pyruvic acid.
D. It is involved in chemiosmosis.
E. ATP synthase is associated with it.
C. It plays a role in the production of pyruvic acid.
385
The mitochondrial cristae are an adaptation that
A. permits the expansion of mitochondria as oxygen accumulates in the mitochondrial matrix.
B. helps mitochondria divide during times of greatest cellular respiration.
C. None of the choices are correct.
D. carefully encloses the DNA housed within the mitochondrial matrix.
E. increases the space for many copies of the electron transport chain and main ATP synthase complexes.
E. increases the space for many copies of the electron transport chain and main ATP synthase complexes.
386
Rotenone is a poison commonly added to insecticides. This molecule binds to the first electron carrier molecule in the electron transport system. Which of the following statements best describes the effect that it has on an insect? The insect will die because
A. None of the choices are correct.
B. anaerobic respiration can't occur.
C. H2O will not be produced and dehydration will occur.
D. high levels of fermentation products will build up.
E. of inadequate ATP production.
E. of inadequate ATP production
387
Cyanide differs from dinitrophenol because cyanide
A. is an electron transport blocker and dinitrophenol is a reaction uncoupler.
B. inhibits the production of ATP by inhibiting ATP synthase; dinitrophenol causes mitochondrial membranes to become less permeable to H+ ions.
C. None of the choices are correct.
D. is highly toxic to human cells and dinitrophenol is nontoxic.
E. makes the membrane of mitochondria leaky to H+ ions and prevents a concentration gradient from building up; dinitrophenol blocks the passage of electrons through electron carriers.
A. is an electron transport blocker and dinitrophenol is a reaction uncoupler.
388
Which of the following statements about the energy yield of aerobic respiration is not true?
A. Most of the ATP derived during aerobic respiration results from chemiosmosis.
B. Each pair of electrons fed into the electron transport chain by an FADH2 or NADH molecule can result in the synthesis of more than one ATP.
C. Less than 50% of the chemical energy available in glucose is converted to ATP energy.
D. ATP may be consumed when transporting the NADH molecules made in glycolysis to the electron transport chain.
E. Glycolysis and the "grooming" of pyruvate together produce more NADH per glucose molecule than does the Krebs cycle.
E. Glycolysis and the "grooming" of pyruvate together produce more NADH per glucose molecule than does the Krebs cycle.
389
Each FADH2 yields a maximum of __________ ATP and each NADH yields a maximum of __________ ATP as a result of transferring pairs of electrons to the electron transport chain.
```
A. 3 . . . 1
B. 2 . . . 3
C. 3 . . . 2
D. 3 . . . 3
E. 1 . . . 3
```
B. 2 . . . 3
390
Both glycolysis and the Krebs cycle must occur __________ time(s) per glucose molecule.
```
A. 5
B. 1
C. 4
D. 2
E. 3
```
D. 2
391
The energy yield from the complete aerobic breakdown of a single glucose
A. can vary with the mechanism used to shuttle NADH electrons into the mitochondrion.
B. increases as the supply of oxygen increases.
C. is always 38 ATP.
D. is less than the yield from anaerobic respiration.
E. is equivalent to the yield from alcoholic fermentation.
A. can vary with the mechanism used to shuttle NADH electrons into the mitochondrion.
392
When an organism such as a yeast lives by fermentation, it converts the pyruvic acid from glycolysis into a different compound, such as alcohol. Why doesn't it secrete the pyruvic acid directly?
A. A buildup of pyruvic acid in the surrounding environment would be too toxic.
B. The conversion yields one ATP per pyruvic acid molecule.
C. The conversion yields one FADH2 per pyruvic acid molecule.
D. The conversion is needed to regenerate the NAD+ consumed during glycolysis.
E. The conversion yields one NADH per pyruvic acid molecule.
D. The conversion is needed to regenerate the NAD+ consumed during glycolysis.
393
Which of the following processes produces the most ATP per molecule of glucose oxidized?
```
A. anaerobic respiration
B. aerobic respiration
C. alcoholic fermentation
D. All produce approximately the same amount of ATP per molecule of glucose.
E. lactic acid fermentation
```
B. aerobic respiration
394
Bacteria that are unable to survive in the presence of oxygen are called
```
A. chemosynthetic bacteria.
B. facultative anaerobes.
C. strict anaerobes.
D. aerobes.
E. microaerophiles.
```
C. strict anaerobes
395
Some friends are trying to make wine in their basement. They've added yeast to a sweet grape juice mixture and have allowed the yeast to grow. After several days they find that sugar levels in the grape juice have dropped, but there's no alcohol in the mixture. The most likely explanation is that:
A. the mixture needs less sugar. High sugar concentrations stimulate cellular respiration, and alcohol is not a by-product of cellular respiration.
B. the mixture needs more oxygen. Yeast need oxygen to break down sugar and get enough energy to produce alcohol.
C. the mixture needs more sugar. Yeast need a lot of energy before they can begin to produce alcohol.
D. None of the choices are correct.
E. the mixture needs less oxygen. Yeast only produce alcohol in the absence of oxygen.
E. the mixture needs less oxygen. Yeast only produce alcohol in the absence of oxygen.
396
Muscle soreness associated with strenuous exercise is at least partly due to
A. the presence of lactic acid produced during fermentation in muscle cells.
B. the accumulation of alcohol from anaerobic respiration.
C. None of the choices are correct.
D. an excess of ATP that builds up during vigorous exercise.
E. the large amount of carbon dioxide that builds up in the muscle.
A. the presence of lactic acid produced during fermentation in muscle cells.
397
In yeast cells,
A. alcohol is produced during the Krebs cycle.
B. lactic acid is produced during glycolysis.
C. alcohol is produced after glycolysis.
D. lactic acid is produced during anaerobic respiration.
E. glucose is produced during photosynthesis.
C. alcohol is produced after glycolysis
398
Yeasts can produce ATP by either fermentation or chemiosmosis; thus they are
```
A. facultative aerobes.
B. strict anaerobes.
C. strict aerobes.
D. facultative an-aerobes.
E. producers of lactic acid.
```
D. facultative an-aerobes.
399
To obtain energy from starch and glycogen, the body must begin by
A. hydrolyzing both starch and glycogen to glucose.
B. None of the choices are correct.
C. hydrolyzing the starch to glucose and the glycogen to amino acids.
D. converting both starch and glycogen to fatty acids.
E. removing nitrogen atoms from both molecules.
A. hydrolyzing both starch and glycogen to glucose.
400
When proteins are used as a source of energy for the body, the proteins
A. are hydrolyzed to their constituent amino acids; electrons are stripped from the amino acids and passed to the electron transport chain.
B. are hydrolyzed to glycerols and then converted to glyceraldehyde 3-phosphate, which is fed into glycolysis.
C. are hydrolyzed to fatty acids and converted to acetyl CoA, which enters the Krebs cycle.
D. are converted into glucose molecules, which are fed into glycolysis.
E. are converted mainly into pyruvic acid, acetyl CoA, or a Krebs cycle intermediate and then processed by the Krebs cycle and chemiosmosis.
E. are converted mainly into pyruvic acid, acetyl CoA, or a Krebs cycle intermediate and then processed by the Krebs cycle and chemiosmosis.
401
When a fatty acid is used for aerobic respiration, it is converted into __________, which is fed into __________.
A. glucose . . . glycolysis
B. glyceraldehyde 3-phosphate . . . glycolysis (partway through)
C. acetyl CoA . . . the Krebs cycle
D. citric acid . . . the Krebs cycle
E. pyruvic acid . . . the pyruvic acid "grooming" step
C. acetyl CoA . . . the Krebs cycle
402
If you consume one gram of each of the following, which will yield the most ATP?
```
A. starch
B. sucrose
C. glucose
D. protein
E. fat
```
E. fat
403
Which one of the following statements is not true? Food provides the raw materials for biosynthetic pathways. These pathways
A. consume ATP.
B. make molecules for cellular repair and growth.
C. can produce sugar by a process that is the exact opposite of glycolysis.
D. can use "intermediate" compounds from glycolysis and the Krebs cycle to make food.
E. can produce molecules that are not actually present in the original food.
C. can produce sugar by a process that is the exact opposite of glycolysis.
404
The conversion of CO2 and H2O into organic compounds using energy from light is called
```
A. glycolysis.
B. fermentation.
C. photosynthesis.
D. photorespiration.
E. cellular respiration.
```
C. photosynthesis
405
The overall equation for photosynthesis is
```
A. C5.H12.O6 + 6 O2 ? 5 CO2 + 6 H2O.
B. 6 CO2 + 6 H2O ? C6H12O6 + 6 O2.
C. C6.H12.O6 + 6 O2 ? 6 CO2 + 6 H2O.
D. None of the choices are correct.
E. the same as the equation for glycolysis written in reverse.
```
B. 6 CO2 + 6 H2O ? C6.H12.O6 + 6 O2
406
Which one of the following statements is not true?
A. Plants that get adequate amounts of light are often tall and spindly, with pale green leaves that are small and spread far apart.
B. Light influences the germination of seeds and the production of flowers.
C. Plants require carbon dioxide, water, and sunlight to make glucose.
D. Photosynthesis is the most important chemical process on Earth.
E. Too much sunlight can be detrimental to a plant.
A. Plants that get adequate amounts of light are often tall and spindly, with pale green leaves that are small and spread far apart.
407
Autotrophs
A. None of the choices are correct.
B. include only the green plants.
C. make organic food molecules from inorganic raw materials.
D. make sugar by using organic raw materials.
E. eat other organisms that use light energy to make food molecules.
C. make organic food molecules from inorganic raw materials.
408
Which of the following is not an example of a photosynthetic autotroph?
A. kelp in an underwater forest
B. fungi
C. purple bacteria often found in tidal mudflats
D. algae
E. herbs like thyme and basil
B. fungi
409
Autotrophs that utilize light as their energy source are
```
A. chemosynthetic autotrophs.
B. heterotrophs.
C. consumers.
D. photosynthetic autotrophs.
E. fungi.
```
D. photosynthetic autotrophs.
410
Producers
A. are autotrophs.
B. All of the choices are correct.
C. manufacture the biosphere's food supply.
D. sustain themselves without eating.
E. make organic food molecules from simple raw materials.
B. All of the choices are correct.
411
In most green plants, chloroplasts are
A. None of the choices are correct.
B. concentrated in a zone of leaf tissue called the mesophyll.
C. concentrated in a portion of the leaf called the stroma.
D. found throughout the leaf tissue.
E. concentrated in the stomata.
B. concentrated in a zone of leaf tissue called the mesophyll.
412
Chloroplasts contain disklike membranous sacs arranged in stacks called
```
A. vacuoles.
B. thylakoids.
C. grana.
D. cristae.
E. stroma.
```
C. grana.
413
In the chloroplast, sugars are made in a compartment that is filled with a thick fluid called the
```
A. stroma.
B. matrix.
C. mesophyll.
D. thylakoid.
E. stomata.
```
A. stroma.
414
Where is chlorophyll found in a plant cell?
```
A. cristae
B. stroma
C. matrix
D. cytoplasm
E. thylakoid membranes
```
E. thylakoid membranes
415
CO2 enters and O2 escapes from a leaf via
```
A. central vacuoles.
B. thylakoids.
C. stroma.
D. grana.
E. stomata.
```
E. stomata.
416
The oxygen released into the air as a product of photosynthesis comes from
```
A. None of these.
B. water.
C. chlorophyll.
D. glucose.
E. carbon dioxide.
```
B. water.
417
Which one of the following molecules is both a reactant and a product of photosynthesis?
```
A. glucose
B. CO2
C. chlorophyll
D. H2O
E. O2
```
D. H2O
418
If you expose a photosynthesizing plant to water that contains both radioactive H and radioactive O, in which of the products of photosynthesis will the radioactive H and O show up?
A. H and O both in glucose
B. H in water; O in glucose
C. H in glucose; O in water
D. H in glucose and water; O in water and O2
E. H in glucose and water; O in O2
E. H in glucose and water; O in O2
419
Which of the following is true concerning the role of redox reactions in photosynthesis and cellular respiration?
A. None of the choices are true.
B. In photosynthesis, carbon dioxide is reduced to form sugar while in respiration, sugar is oxidized to form carbon dioxide.
C. Photosynthesis involves only reductions while respiration involves only oxidations.
D. Photosynthesis involves only oxidations while respiration involves only reductions.
E. In photosynthesis, carbon dioxide is oxidized to form sugar while in respiration, sugar is reduced to form carbon dioxide.
B. In photosynthesis, carbon dioxide is reduced to form sugar while in respiration, sugar is oxidized to form carbon dioxide.
420
Which one of the following statements is not true?
A. Photosynthesis consumes CO2; respiration consumes O2.
B. ATP is only produced during respiration. ATP is not produced during photosynthesis.
C. Photosynthesis is ultimately powered by light energy; respiration, by the chemical energy of fuel molecules.
D. Photosynthesis produces O2; respiration produces CO2.
E. The principal electron carrier in photosynthesis is NADPH; the principal electron carrier in respiration is NADH.
B. ATP is only produced during respiration. ATP is not produced during photosynthesis.
421
The light reactions occur in the __________ while the Calvin cycle occurs in the __________.
```
A. stroma . . . nucleus
B. cytoplasm . . . stroma
C. cytoplasm . . . thylakoid membrane
D. stroma . . . thylakoid membranes
E. thylakoid membranes . . . stroma
```
E. thylakoid membranes . . . stroma
422
Which of the following are produced during the light reactions of photosynthesis?
```
A. glucose, ADP, NADP+
B. ATP, NADPH, O2
C. glucose, ADP, NADP+, CO2
D. ADP, NADP+, O2
E. ATP, NADPH, CO2
```
B. ATP, NADPH, O2
423
Which of the following are produced during the Calvin cycle?
```
A. glucose, ADP, NADP+, CO2
B. ATP, NADPH, CO2
C. glucose, ADP, NADP+
D. ATP, NADPH, O2
E. ADP, NADP+, O2
```
C. glucose, ADP, NADP+
424
Carbon fixation
A. provides the cell with a supply of NADPH molecules.
B. uses noncyclic electron flow to capture energy in glucose.
C. occurs when carbon and oxygen from CO2 are incorporated into an organic molecule.
D. occurs during the light reactions.
E. powers the process of glucose synthesis by supplying the cell with ATP.
C. occurs when carbon and oxygen from CO2 are incorporated into an organic molecule.
425
The Calvin cycle involves all of the following except:
A. reduction of carbon.
B. carbon fixation.
C. formation of waste products in the form of CO2.
D. regeneration of NADP+.
E. addition of electrons and protons to carbon.
C. formation of waste products in the form of CO2.
426
Sunlight is a type of __________ energy.
```
A. kinetic
B. electromagnetic and kinetic
C. electromagnetic
D. potential
E. stored
```
B. electromagnetic and kinetic
427
Why are (most) plants green?
A. Chlorophyll reflects green light.
B. Chlorophyll absorbs green light.
C. Green is the best color of light for plant growth.
D. Carotenoids reflect green light.
E. Chlorophyll primarily uses green light as the source of energy for photosynthesis.
A. Chlorophyll reflects green light.
428
Of the following wavelengths of light, which would you expect to be least absorbed by chlorophyll a?
```
A. blue
B. red
C. yellow
D. orange
E. green
```
E. green
429
Chlorophyll b
A. catalyzes the incorporation of carbon atoms into RuBP.
B. is located on the inner membrane of the chloroplast.
C. passes absorbed energy to chlorophyll a.
D. is found at the reaction center.
E. is best at absorbing the energy of green light.
C. passes absorbed energy to chlorophyll a.
430
During the fall many trees break down the chlorophyll in their leaves. The color of these leaves during the fall is attributable to
```
A. P680.
B. carotenoids.
C. melanin.
D. photosystems.
E. P700.
```
B. carotenoids.
431
Which one of the following photosynthetic pigments can be found at the photosystem reaction center?
```
A. chlorophyll b
B. phycocyanin
C. a carotenoid
D. None of the choices are correct.
E. chlorophyll a
```
E. chlorophyll a
432
Which one of the following is a normal process of photosynthesis that would be unable to occur if all reaction centers were inactivated by a toxin?
A. donation of excited electrons by chlorophyll b to a primary electron acceptor
B. None of the choices are correct.
C. donation of excited electrons by chlorophyll a to a primary electron acceptor
D. reduction of chlorophyll b by a primary electron acceptor
E. absorption of photons by chlorophyll b
C. donation of excited electrons by chlorophyll a to a primary electron acceptor
433
How do the reaction centers of photosystem I and II differ?
A. None of the choices are correct.
B. Chlorophyll a is found in photosystem I, and chlorophyll b in photosystem II.
C. Only photosystem I is found in the thylakoid membranes.
D. One is located in the thylakoid membrane, and the other in the stroma.
E. They preferentially absorb slightly different wavelengths of light.
E. They preferentially absorb slightly different wavelengths of light.
434
A packet of light energy is called a
```
A. wavelength.
B. phaser.
C. photon.
D. pigment.
E. quantum.
```
C. photon.
435
When a pigment molecule absorbs a photon, one of its electrons
```
A. gains energy.
B. becomes excited.
C. is raised from the ground state.
D. is put into an unstable state.
E. All of the choices are correct.
```
E. All of the choices are correct.
436
Energy can be released from a pigment with an excited electron
A. by emitting photons, as in fluorescence.
B. by oxidation.
C. as light.
D. as heat.
E. All of the choices are correct.
E. All of the choices are correct.
437
Antenna molecules
```
A. pass energy to the reaction center.
B. absorb electrons.
C. are found in the roots of plants.
D. break down H2O
E. do not absorb photons.
```
A. pass energy to the reaction center.
438
The energy that excites P680 and P700 is supplied by
A. electrons passing down the electron transport chain.
B. ATP.
C. NADPH.
D. photons.
E. the breaking of glucose bonds.
D. photons.
439
The electron transport chains of the light reactions
A. are located in the stroma.
B. provide energy for the Krebs cycle.
C. are found on the inner membrane of chloroplasts.
D. shuttle electrons along in a series of redox reactions.
E. are not similar to those of cellular respiration.
D. shuttle electrons along in a series of redox reactions.
440
As a result of the cascade of electrons down the electron transport chains of the light reactions,
```
A. NADPH is reduced to NADP+.
B. water is formed.
C. NADP+ is oxidized to NADPH.
D. NADP+ is reduced to NADPH.
E. NADPH is oxidized to NADP+.
```
D. NADP+ is reduced to NADPH.
441
The electrons lost from the reaction center of photosystem I are replaced by electrons from
```
A. ATP.
B. photosystem II.
C. NADPH.
D. H2O
E. CO2.
```
B. photosystem II.
442
The electrons lost from the reaction center of photosystem II are replaced by electrons from
```
A. photosystem I.
B. H2O.
C. NADPH.
D. ATP.
E. CO2.
```
B. H2O.
443
Photosystem II
```
A. is reduced by NADPH.
B. All of the choices are correct.
C. does not have a reaction center.
D. has P700 at its reaction center.
E. passes electrons to photosystem I.
```
E. passes electrons to photosystem I.
444
Photosynthetic chemiosmosis differs from respiratory chemiosmosis in that
A. energy is stored in the form of a proton concentration difference.
B. its enzymes are membrane bound.
C. it involves an electron transport chain.
D. regeneration of ATP is driven by a flow of protons through an ATP synthase.
E. the final electron acceptor is NADP+.
E. the final electron acceptor is NADP+.
445
In chemiosmosis, energy from electron flow is used to transport __________ from the __________ to the thylakoid compartment, generating a concentration gradient of __________.
```
A. H+. . . stroma . . . ATP
B. electrons . . . grana . . . H+
C. H+. . . grana . . . electrons
D. H+. . . stroma . . . H+
E. electrons . . . stroma . . . H+
```
D. H+. . . stroma . . . H+
446
Which one of the following is not a characteristic of the chloroplast ATP synthase?
A. It transports H+S from the thylakoid compartment to the stroma.
B. It is a protein complex.
C. The ATP it produces is formed in the thylakoid compartment.
D. It is embedded in the thylakoid membrane.
E. It uses the energy from active transport of H+ into the stroma to phosphorylate ADP to ATP.
A. It transports H+S from the thylakoid compartment to the stroma.
447
In photosynthesis, the chemiosmotic production of ATP
A. All of the choices are correct.
B. is done by the Calvin cycle.
C. is analogous to the production of ATP in mitochondria.
D. requires oxygen.
E. requires the input of NADPH.
C. is analogous to the production of ATP in mitochondria.
448
Photosynthetic organisms derive their carbon from
```
A. carbon monoxide.
B. carbon dioxide.
C. hydrocarbons.
D. methane.
E. All of the choices depend on environmental conditions.
```
B. carbon dioxide.
449
To produce one glucose, the Calvin cycle needs to be run through __________ time(s).
```
A. one
B. two
C. four
D. six
E. eight
```
D. six
450
ATP and NADPH
A. production is associated with events taking place on the inner mitochondrial membrane.
B. play a role in glucose synthesis by plants.
C. All of the choices are correct.
D. are inputs to the photosystems.
E. are products of the Calvin cycle.
B. play a role in glucose synthesis by plants
451
The Calvin cycle constructs __________, an energy-rich molecule that a plant cell can then use to make glucose or other organic molecules.
```
A. ATP
B. carbon dioxide
C. NADPH
D. NADH
E. G3P
```
E. G3P
452
What is photorespiration?
A. the opening and closing of stomata in response to changes in light intensity
B. light-driven cleavage of glucose to yield three two-carbon compounds, which are broken down to CO2 and H2O without producing ATP
C. the incorporation of O2 instead of CO2 by rubisco, yielding a two-carbon compound that is broken down to CO2 and H2O
D. ATP synthesis driven by light energy
E. the increase in the rate of mitochondrial respiration that takes place when a leaf is exposed to light and photosynthesis produces glucose
C. the incorporation of O2 instead of CO2 by rubisco, yielding a two-carbon compound that is broken down to CO2 and H2O
453
What is the main advantage of the C4 and CAM photosynthesis strategies over the C3 strategy?
A. They allow the plant to fix carbon more efficiently under conditions of low atmospheric CO2.
B. They make it possible for the plant to use the Calvin cycle at night as well as during the day.
C. They help the plant both conserve water and synthesize glucose efficiently under hot, dry conditions.
D. They allow the plant to avoid photorespiration by producing a four-carbon sugar in place of glucose.
E. They allow the plant to fix carbon more efficiently in dim or cool conditions.
C. They help the plant both conserve water and synthesize glucose efficiently under hot, dry conditions.
454
Do photosynthesizing plants have mitochondria?
A. Yes, but only in CAM plants, in which carbon is fixed at night.
B. Yes, to convert glucose into starch.
C. No, chloroplasts produce ATP as well as glucose.
D. Yes, but they are used mainly to produce certain Krebs cycle intermediates, which are needed for the synthesis of compounds such as amino acids.
E. Yes, to supply the plant with the ATP needed to power various cell activities.
E. Yes, to supply the plant with the ATP needed to power various cell activities.
455
Which of the following choices incorrectly pairs a crop plant with the photosynthetic strategy it uses?
```
A. pineapple, CAM
B. sugarcane, C4
C. soybean, C3
D. corn, C3
E. wheat, C3
```
D. corn, C3
456
Photorespiration
A. is detrimental to the plant since it breaks down rubisco.
B. is of benefit to the plant since it breaks down rubisco.
C. produces ATP.
D. is attributable to high CO2 levels.
E. produces glucose.
A. is detrimental to the plant since it breaks down rubisco.
457
The greenhouse effect is
A. improved by the addition of carbon dioxide to the atmosphere, since carbon dioxide removes excess heat from the Earth's surface and reflects it back into space.
B. improved by the burning of wood, because this adds carbon dioxide to the atmosphere.
C. made worse by photosynthesis, which adds carbon dioxide to the atmosphere.
D. counteracted by the burning of fossil fuels, which removes oxygen from the atmosphere.
E. counteracted by photosynthesis, which removes carbon dioxide from the atmosphere.
E. counteracted by photosynthesis, which removes carbon dioxide from the atmosphere.
458
The greenhouse effect
A. is enhanced by the use of fossil fuels.
B. will increase the average temperature of the planet.
C. All of the choices are correct.
D. is enhanced by deforestation.
E. is enhanced by increasing levels of atmospheric CO2.
C. All of the choices are correct.
459
It has been argued that cutting old-growth forests and replacing them with plantations of young trees would help to alleviate the threat of global greenhouse warming. What important fact does this argument ignore?
A. Most of the young trees would die within a few years.
B. Young trees fix carbon at a lower rate per unit mass than old trees.
C. Young trees emit ozone-destroying gases at a higher rate than old trees, and thus would worsen the ozone-hole problem while alleviating global warming.
D. Forests play too minor a role in global CO2 dynamics. (The major role is played by marine algae.)
E. Most of the biomass of the cut trees would be added to the atmosphere as CO2 within a few years.
E. Most of the biomass of the cut trees would be added to the atmosphere as CO2 within a few years.
460
Ozone consists of __________ oxygen atom(s).
```
A. zero
B. four
C. one
D. two
E. three
```
E. three
461
Ozone
A. protects Earth from UV radiation.
B. formation is promoted by CFCs.
C. is a source of oxygen for cellular respiration.
D. is broken down by carbon dioxide.
E. levels in the atmosphere continue to increase.
A. protects Earth from UV radiation.
462
A small oak seedling weighing less than 6 ounces is planted in a pot that contains 150 pounds of soil. Approximately 1 pound of nitrogen and phosphorus fertilizer is added to the soil. For 2 years, the plant is given plenty of water and light. At the end of the experiment, the plant weighs nearly 25 pounds. You would expect
A. the soil to have gained weight, since the plant has been releasing waste products into it.
B. a significant loss in the amount of nitrogen and phosphorus in the soil.
C. the soil to weigh approximately 25 pounds less than when you started the experiment.
D. None of the choices are correct.
E. considerable changes in soil weight.
B. a significant loss in the amount of nitrogen and phosphorus in the soil.
463
The creation of offspring carrying genetic information by just a single parent is called
```
A. regeneration.
B. sexual reproduction.
C. None of the choices are correct.
D. asexual reproduction.
E. a life cycle.
```
D. asexual reproduction.
464
Which one of the following is a difference between sexual and asexual reproduction?
A. Sexual reproduction produces more offspring.
B. Asexual reproduction always increases the number of sets of chromosomes in the offspring; sexual reproduction decreases the number of sets of chromosomes in the offspring.
C. Sexual reproduction includes the development of unfertilized eggs.
D. Regeneration is exclusive to sexual reproduction.
E. Sexual reproduction is more likely to increase genetic variation than is asexual reproduction.
E. Sexual reproduction is more likely to increase genetic variation than is asexual reproduction.
465
Strictly speaking, the phrase "like begets like" refers to
```
A. None of the choices are correct.
B. sexual reproduction only.
C. all forms of reproduction.
D. asexual reproduction only.
E. production of gametes from a premeiotic cell.
```
D. asexual reproduction only.
466
With the exception of identical twins, siblings who have the same two biological parents are likely to look similar, but not identical, to each other because they have
A. no gene variants in common.
B. only a 50% chance of being the same sex.
C. some gene variants in common.
D. some gene variants in common and some variants not found in the other.
E. gene variants not found in the other.
D. some gene variants in common and some variants not found in the other.
467
Virchow's simple and profound principle, stated formally in 1858, was that
```
A. animals must develop.
B. all cells come from cells.
C. all life evolves.
D. photosynthesis is the center of all life.
E. animals must always reproduce
```
B. all cells come from cells.
468
Which one of the following is not true? Cell division
A. is common in eukaryotes but rare in prokaryotes.
B. ensures the continuity of life from generation to generation.
C. is necessary for development to occur.
D. is the basis of both sexual and asexual reproduction.
E. is commonly referred to as cell reproduction.
A. is common in eukaryotes but rare in prokaryotes.
469
Which one of the following is not true?
A. Daughter prokaryotic chromosomes are separated by some sort of active movement away from each other and the growth of new plasma membrane between them.
B. In prokaryotes, most genes are carried on a circular DNA molecule.
C. Prokaryotic cells are generally smaller and simpler than eukaryotic cells.
D. Prokaryotic chromosomes are more complex than those of eukaryotes.
E. Most prokaryotic organisms reproduce mainly by the process of binary fission.
D. Prokaryotic chromosomes are more complex than those of eukaryotes.
470
Sister chromatids are
A. formed when chromatids separate during cell division.
B. made only of DNA.
C. tightly linked together at the centromere.
D. found only when a cell is not actively dividing.
E. unique to prokaryotes.
C. tightly linked together at the centromere.
471
Compared to prokaryotic chromosomes, eukaryotic chromosomes
A. include fewer proteins.
B. are circular in structure.
C. are not copied prior to cell division.
D. are housed in a membrane-enclosed nucleus.
E. are simpler.
D. are housed in a membrane-enclosed nucleus.
472
Prior to mitosis, each chromosome of a eukaryotic cell consists of a pair of identical structures called
```
A. DNA transcripts.
B. chromatin.
C. nucleoli.
D. sister chromosomes.
E. sister chromatids.
```
E. sister chromatids.
473
Eukaryotic cells spend most of their cell cycle in which phase?
```
A. prophase
B. anaphase
C. telophase
D. interphase
E. metaphase
```
D. interphase
474
The process by which the cytoplasm of a eukaryotic cell divides to produce two cells is called
```
A. binary fission.
B. cytokinesis.
C. telophase.
D. mitosis.
E. spindle formation.
```
B. cytokinesis
475
If the S phase was eliminated from the cell cycle, the daughter cells would
A. None of the choices are correct.
B. have half the genetic material found in the parental cell.
C. be genetically identical.
D. synthesize the missing genetic material on their own.
E. be genetically identical to the parental cell.
B. have half the genetic material found in the parental cell.
476
Which of the following occurs during interphase?
```
A. cell growth
B. growth of the aster
C. cell growth and duplication of the chromosomes
D. duplication of the chromosomes
E. None of the choices are correct.
```
C. cell growth and duplication of the chromosomes
477
The phase of mitosis during which the nuclear envelope fragments and the nucleoli disappear is called
```
A. metaphase.
B. interphase.
C. telophase.
D. prophase.
E. anaphase.
```
D. prophase.
478
During which phase of mitosis do the chromosomes line up on a plane located equidistant from the two spindle poles?
```
A. anaphase
B. interphase
C. metaphase
D. telophase
E. prophase
```
C. metaphase
479
Which one of the following does not occur during mitotic anaphase?
A. Daughter chromosomes begin to move toward opposite poles of the cell.
B. All of the choices occur during mitotic anaphase.
C. The chromatid DNA replicates.
D. The centromeres of each chromosome divide.
E. Sister chromatids separate.
C. The chromatid DNA replicates.
480
During which phase of mitosis does the nuclear envelope re-form and the nucleoli reappear?
```
A. prophase
B. anaphase
C. interphase
D. metaphase
E. telophase
```
E. telophase
481
Which of the following is a feature of plant cell division that distinguishes it from animal cell division?
A. The nucleolus disappears and then reappears.
B. A cell plate forms.
C. Cytokinesis does not occur.
D. Four new cells (rather than two) are produced per mitotic division.
E. A cleavage furrow forms.
B. A cell plate forms.
482
Which of the following is likely to account for the difference between plant and animal cell cytokinesis?
A. Animal cells lack chloroplasts.
B. Plant cells have two sets of chromosomes; animal cells have one set of chromosomes.
C. Plant and animal cells do not have a common ancestor.
D. Plant cells lack the microfilaments required for forming a cleavage furrow.
E. Plant cell division must maintain the integrity of the cell wall.
E. Plant cell division must maintain the integrity of the cell wall.
483
Which of the following must occur for a plant or animal to grow and develop normally?
A. Sufficient light must be available to stimulate cell division.
B. None of the choices are correct.
C. It must be able to control the timing and rate of cell division in different parts of its body.
D. Sufficient oxygen must be available to stimulate cell division.
E. The organism must receive a supply of the appropriate hormones from its parents.
C. It must be able to control the timing and rate of cell division in different parts of its body.
484
When animal cells are grown in a petri dish, they typically stop dividing once they have formed a single, unbroken layer on the bottom of the dish. This arrest of division is an example of
```
A. cell division repression.
B. cancer.
C. cell constraint.
D. growth factor desensitization.
E. density-dependent inhibition.
```
E. density-dependent inhibition.
485
Which of the following is probably the main factor responsible for the phenomenon of density-dependent inhibition?
A. a local deficiency of nutrients
B. the absence of growth factors
C. a local accumulation of growth-inhibiting factors
D. None of the choices are correct.
E. cells' innate "sense" of knowing when the organ of which they are a part has no need for additional cells
B. the absence of growth factors
486
Tissue-cultured skin cells will stop dividing when which of the following occurs?
A. The cells run out of growth factors due to the crowding of neighboring cells.
B. A clearing occurs that inhibits all cells in the culture.
C. The toxic waste products from other cells in the culture cause significant changes in the pH.
D. The cells reach the end of their reproductive life.
E. Neighboring cells release cell division repressor factors.
A. The cells run out of growth factors due to the crowding of neighboring cells.
487
Mature human nerve cells and muscle cells
A. cease dividing after a predetermined number of cell generations.
B. remain undifferentiated unless an injury occurs.
C. continue to divide throughout their lifetime.
D. become cancerous more easily than other cell types.
E. are permanently in a state of nondivision.
E. are permanently in a state of nondivision.
488
The cell-cycle control system
A. is influenced by growth factors that bind to cell receptors.
B. All of the choices are correct.
C. receives messages from outside of the cell that influence cell division.
D. triggers and controls major events in the cell cycle.
E. includes three key checkpoints to complete a cell cycle.
B. All of the choices are correct.
489
You are asked to culture an unidentified sample of animal tissue. You notice that the cells seem not to exhibit density-dependent inhibition. Which of the following choices would be the most likely source for this tissue sample?
```
A. a cancer
B. the fetal liver
C. the sperm-producing tissue of the testis
D. the skin
E. a scar
```
A. a cancer
490
A benign tumor differs from a malignant tumor in that a benign tumor
A. is cancerous.
B. never causes health problems.
C. can only arise in the brain, whereas a malignant tumor can arise anywhere in the body.
D. spreads from the original site.
E. does not metastasize.
E. does not metastasize.
491
You are the director of research for a drug company. The following list of candidate drugs is brought to you. Which is the most likely to be worth developing as a cancer chemotherapy agent? A drug that
A. prevents tetrad formation.
B. causes cells to divide at a right angle from their usual orientation.
C. interferes with cellular respiration.
D. prevents sister chromatids from separating at anaphase.
E. prevents crossing over.
D. prevents sister chromatids from separating at anaphase.
492
Which one of the following is not a function of mitosis? Mitosis helps organisms
```
A. All of the choices are correct.
B. repair tissues.
C. reproduce asexually.
D. regenerate lost parts.
E. grow.
```
A. All of the choices are correct.
493
Two chromosomes in a nucleus that carry loci for the same traits in the same positions on the chromosome but specify different versions of some traits constitute a pair of
```
A. homologous chromosomes.
B. complementary chromosomes.
C. None of the choices are correct.
D. heterologous chromosomes.
E. polyploid chromosomes.
```
A. homologous chromosomes.
494
Which one of the following statements is not true?
A. Somatic cells are diploid.
B. A zygote is a fertilized egg.
C. Gametes are made by mitosis.
D. Gametes are haploid cells.
E. A typical body cell is called a somatic cell.
C. Gametes are made by mitosis.
495
Which of the following is a consequence of a reproduction system that is based on the union of haploid gametes?
A. offspring that have enhanced genetic diversity and a diploid chromosome complement that is the same size as their parents'
B. offspring that have enhanced genetic diversity and a diploid chromosome complement that is twice the size of their parents'
C. a reduction in the number of offspring with undesirable traits
D. the prevention of sexual reproduction
E. offspring with enhanced homozygosity
A. offspring that have enhanced genetic diversity and a diploid chromosome complement that is the same size as their parents'
496
During which stage of meiosis do synapsis and the formation of tetrads occur?
```
A. interphase I
B. prophase I
C. interphase II
D. None of the choices are correct.
E. prophase II
```
B. prophase I
497
Which one of the following choices best describes the behavior of a tetrad during anaphase I of meiosis?
A. It splits into two pairs of homologous, nonsister chromatids, and one pair goes to each pole of the dividing cell.
B. It goes intact to one pole of the dividing cell.
C. It splits into four chromosomes, which distribute in sister-chromosome pairs to the two poles of the dividing cell.
D. It splits into four chromosomes, which distribute in random pairs to the two poles of the dividing cell.
E. It splits into two pairs of sister chromatids, and one pair goes to each pole of the dividing cell.
E. It splits into two pairs of sister chromatids, and one pair goes to each pole of the dividing cell.
498
Which of the following is a difference between mitosis and meiosis?
A. Cells produced by mitosis are diploid; cells produced by meiosis are haploid.
B. In meiosis four daughter cells are produced, whereas in mitosis two daughter cells are produced.
C. In mitosis cytokinesis occurs once, whereas in meiosis cytokinesis occurs twice.
D. All of the choices are correct.
D. All of the choices are correct.
499
Which of the following aspects of reproduction enhances genetic diversity?
A. random fertilization
B. independent orientation of chromosomes
C. mitosis
D. random fertilization and mitosis
E. random fertilization and independent orientation of chromosomes
E. random fertilization and independent orientation of chromosomes
500
Independent orientation results in an increase in the number of
```
A. homologous chromosomes.
B. points of crossing over.
C. gametes.
D. possible combinations of characteristics.
E. sex chromosomes.
```
D. possible combinations of characteristics.
501
Karyotyping
A. can reveal alterations in chromosome number.
B. reveals the presence of cancerous genes.
C. reveals the results of independent orientation of chromosomes during meiosis I.
D. examines points of crossing over.
E. shows chromosomes as they appear in metaphase of meiosis II.
A. can reveal alterations in chromosome number.
502
Which one of the following is not true?
A. Trisomy 21 usually leads to Down syndrome.
B. Down syndrome is the most common serious birth defect in the United States.
C. People with Down syndrome usually have a life span much shorter than normal.
D. Women with Down syndrome can not reproduce.
E. A human embryo with an abnormal number of chromosomes is usually spontaneously aborted.
D. Women with Down syndrome can not reproduce.
503
Nondisjunction occurs when
A. a portion of a chromosome breaks off and is lost.
B. two chromosomes fuse into one.
C. an entire pair of chromosomes is lost during meiosis I.
D. members of a chromosome pair fail to separate.
E. chromosomes replicate too many times.
D. members of a chromosome pair fail to separate.
504
Which one of the following is not true?
A. In mammals, extra copies of the Y chromosome are typically inactivated.
B. The absence of a Y chromosome results in "femaleness."
C. Women with a single X chromosome have Turner syndrome and are sterile.
D. In general, a single Y chromosome is enough to produce "maleness."
E. Nondisjunction in meiosis can affect autosomes and sex chromosomes.
A. In mammals, extra copies of the Y chromosome are typically inactivated.
505
If a chromosome fragment breaks off and then reattaches to the original chromosome but in the reverse direction, the resulting chromosomal abnormality is called a(n)
```
A. deletion.
B. translocation.
C. nondisjunction.
D. inversion.
E. reciprocal translocation.
```
D. inversion.
506
Examine the following sentence. "Where is the cat?" Which one of the following variations of this sentence is most like a chromosomal deletion?
```
A. Where the is cat?
B. Where is cat?
C. Where is cat the the cat?
D. Where is the the cat?
E. Where is is is is the cat?
```
B. Where is cat?
507
Cancer is not usually inherited because
A. the causes of cancer are not usually genetic.
B. the chromosomal changes in cancer are usually confined to somatic cells.
C. people with cancer usually die before reproducing.
D. the cancerous cells usually interfere with the ability to produce gametes.
E. cancer typically causes disruptions of meiosis.
B. the chromosomal changes in cancer are usually confined to somatic cells.
508
The student must save each answer of the quiz/test and click "Finish" at the bottom to properly submit the quiz/test.
A. True
B. False
B. False
509
Which one of the following statements is not true?
A. About 60% of the genetic disorders in dogs are similar to human genetic diseases.
B. A dog's behavioral characteristics are influenced by its genetics and its environment.
C. A human's behavioral characteristics are influenced by its genetics and its environment.
D. Dogs of different breeds have different temperaments.
E. It is more difficult to trace patterns of inheritance in purebred dogs .
E. It is more difficult to trace patterns of inheritance in purebred dogs
510
Which one of the following statements best represents the theory of pangenesis developed by Hippocrates?
A. Particles called pangenes originating in each part of an organism's body collect in the sperm and eggs and are passed on to the next generation.
B. Fertilization of plants is dependent on an animal.
C. Pregnancy is a spontaneous event, and the characteristics of the offspring are determined by the gods.
D. Offspring inherit the traits of either the mother or the father but not both.
E. None of the choices are correct.
A. Particles called pangenes originating in each part of an organism's body collect in the sperm and eggs and are passed on to the next generation.
511
Which one of the following statements is not true?
A. Pangenesis is incorrect in part because changes in somatic cells do not influence eggs or sperm.
B. The blending hypothesis suggested that all of the traits of the offspring come from either the mother or the father.
C. Pangenesis is incorrect in part because reproductive cells are not composed of particles from somatic cells.
D. Aristotle suggested that inheritance is the potential to produce body features.
E. The blending hypothesis does not explain how traits that disappear in one generation can reappear in later generations.
B. The blending hypothesis suggested that all of the traits of the offspring come from either the mother or the father.
512
Which one of the following is not true?
A. The parental plants of a cross are the P generation.
B. The offspring of two different varieties are called hybrids.
C. The hybrid offspring of a cross are the P1 generation.
D. The cross-fertilization or hybridization is also called a cross.
E. The hybrid offspring of an F1 cross are the F2 generation.
C. The hybrid offspring of a cross are the P1 generation.
513
Varieties of plants in which self-fertilization produces offspring that are identical to the parents are referred to as
```
A. true-breeding.
B. independent crosses.
C. the F2 generation.
D. monohybrid crosses.
E. hybrids.
```
A. true-breeding.
514
A monohybrid cross is
A. the second generation of a self-fertilized plant.
B. None of the choices are correct.
C. a triploid plant that results from breeding two very different plants.
D. a breeding experiment in which the parental varieties differ in only one trait.
E. a breeding experiment in which the parental varieties have only one trait in common.
D. a breeding experiment in which the parental varieties differ in only one trait.
515
Research since Mendel's time has established that the principle of the segregation of genes during gamete formation
A. applies to all asexually reproducing organisms.
B. applies only to unicellular organisms.
C. applies to all sexually reproducing organisms.
D. applies to all forms of life.
E. is invalid.
C. applies to all sexually reproducing organisms.
516
Which one of the following is not true?
A. An organism with two different alleles for a single trait is said to be heterozygous.
B. An allele that is fully expressed is referred to as recessive.
C. Alleles are alternate forms of a gene.
D. The expressed physical traits of an organism are called its phenotype.
E. The genetic makeup of an organism constitutes its genotype.
B. An allele that is fully expressed is referred to as recessive.
517
Alleles of a gene are found at __________ chromosomes.
```
A. the same locus on homologous
B. the same locus on homologous mitochondrial
C. different loci on homologous
D. the same locus on heterologous
E. different loci on heterologous
```
A. the same locus on homologous
518
Mendel's principle of independent assortment states that
A. each pair of alleles segregates independently during gamete formation.
B. independent sorting of genes produces polyploid plants under some circumstances.
C. None of the choices are correct.
D. chromosomes sort independently of each other during mitosis and meiosis.
E. genes sort independently of each other in animals but not in plants.
A. each pair of alleles segregates independently during gamete formation
519
Imagine that we mate two black Labrador dogs with normal vision and find that 3 of the puppies are like the parents, but one puppy is chocolate with normal vision, and another is black with PRA (progressive retinal atrophy, a serious disease of vision). We can conclude that
A. the alleles for color and vision segregate independently during gamete formation.
B. the same alleles that control coat color can also cause PRA.
C. both of the parents are homozygous for both traits.
D. one of the parents is homozygous for both traits.
E. the alleles for color and vision segregate dependently during gamete formation.
A. the alleles for color and vision segregate independently during gamete formation.
520
What is a testcross?
A. None of the choices are correct.
B. a mating between two individuals heterozygous for the trait of interest
C. a mating between an individual of unknown genotype and an individual homozygous dominant for the trait of interest
D. a mating between an individual of unknown genotype and an individual homozygous recessive for the trait of interest
E. a mating between an individual of unknown genotype and an individual heterozygous for the trait of interest
D. a mating between an individual of unknown genotype and an individual homozygous recessive for the trait of interest
521
Using a six-sided die, what is the probability of rolling either a 5 or a 6?
```
A. 1/6 + 1/6 = 1/3
B. 1/6 x 1/6 = 1/3
C. 1/6
D. 1/6 x 1/6 = 1/36
E. 1/6 + 1/6 = 1/12
```
A. 1/6 + 1/6 = 1/3
522
Assuming that the probability of having a female child is 50% and the probability of having a male child is also 50%, what is the probability that a couple's first-born child is female and second-born child is male?
```
A. 75%
B. None of the choices are correct.
C. 25%
D. 100%
E. 50%
```
C. 25%
523
A carrier of a genetic disorder who does not show symptoms is most likely to be __________ to transmit it to offspring.
```
A. heterozygous for the trait and unable
B. homozygous for the trait and able
C. heterozygous for the trait and able
D. None of the choices are correct.
E. homozygous for the trait and unable
```
C. heterozygous for the trait and able
524
Dr. Smith's parents have normal hearing. However, Dr. Smith has an inherited form of deafness. Deafness is a recessive trait that is associated with the abnormal allele d. The normal allele at this locus, associated with normal hearing, is D. Dr. Smith's parents could have which of the following genotypes?
```
A. Dd and Dd
B. None of the choices are correct.
C. DD and dd
D. DD and DD
E. dd and dd
```
A. Dd and Dd
525
Many genetic disorders of humans are caused by
```
A. dominant alleles.
B. None of the choices are correct.
C. drinking during pregnancy.
D. recessive alleles.
E. a mutation that occurs in the egg, sperm, or zygote that gives rise to the affected individual.
```
D. recessive alleles.
526
The vast majority of people afflicted with recessive disorders are born to parents who were
A. subjected to some environmental toxin that caused the disease in their children.
B. None of the choices are correct.
C. both affected by the disease.
D. not affected at all by the disease.
E. slightly affected by the disease, showing some but not all of the symptoms.
D. not affected at all by the disease.
527
Which of the following best explains why dominant alleles that cause lethal disorders are less common than recessive alleles that cause lethal disorders?
A. Lethal disorders caused by dominant alleles are usually more severe than lethal disorders caused by recessive alleles.
B. The presence of a lethal dominant allele causes sterility.
C. Unlike lethal disorders caused by recessive alleles, lethal disorders caused by dominant alleles usually cause death of the embryo.
D. Many lethal recessive alleles cause enhanced disease resistance when they are present in the heterozygous state, and carriers of these alleles have more children, on average, than other people.
E. Most individuals carrying a lethal dominant allele have the disorder and die before they reproduce, whereas individuals carrying a lethal recessive allele are more likely to be healthy and reproduce.
E. Most individuals carrying a lethal dominant allele have the disorder and die before they reproduce, whereas individuals carrying a lethal recessive allele are more likely to be healthy and reproduce.
528
Both amniocentesis and chorionic villus sampling allow for __________ and __________ of the fetus so that it can be tested for abnormalities.
A. sexing . . . imaging
B. karyotyping . . . biochemical testing
C. imaging . . . biochemical testing
D. imaging . . . karyotyping
E. direct observation . . . biochemical testing
B. karyotyping . . . biochemical testing
529
Which one of the following is not true?
A. Chorionic villus sampling and amniocentesis are usually reserved for pregnancies with higher than usual risks of complications.
B. Ultrasound imaging has no known risk.
C. Results from chorionic villus sampling come faster than from amniocentesis.
D. Chorionic villus sampling is typically performed later in the pregnancy than amniocentesis.
E. The complication rate for chorionic villus sampling is about 2% and for amniocentesis is about 1%.
D. Chorionic villus sampling is typically performed later in the pregnancy than amniocentesis.
530
Which one of the following is not true?
A. Incomplete dominance supports the blending hypothesis.
B. The impact of a single gene on more than one characteristic is called pleiotropy.
C. ABO blood groups can provide evidence of paternity.
D. The four blood types result from various combinations of the three different ABO alleles.
E. Heterozygotes for hypercholesterolemia have blood cholesterols about twice normal.
A. Incomplete dominance supports the blending hypothesis.
531
Which one of the following is an example of incomplete dominance in humans?
```
A. ABO blood groups
B. sickle-cell disease
C. pink coloration in snapdragons
D. hypercholesterolemia
E. None of the choices are correct.
```
D. hypercholesterolemia
532
Imagine that beak color in a finch species is controlled by a single gene. You mate a finch homozygous for orange (pigmented) beak with a finch homozygous for ivory (unpigmented) beak and get numerous offspring, all of which have a pale, ivory-orange beak. This pattern of color expression is most likely to be an example of
```
A. polygenic inheritance.
B. pleiotropy.
C. crossing over.
D. incomplete dominance.
E. codominance.
```
D. incomplete dominance.
533
The expression of both alleles for a trait in a heterozygous individual is
```
A. blending inheritance.
B. pleiotropy.
C. codominance.
D. polygenic inheritance.
E. incomplete dominance.
```
C. codominance.
534
Which one of the following is not true?
A. Persons who are heterozygous for sickle-cell disease are also resistant to malaria.
B. White blood cells are sickle shaped in sickle-cell disease.
C. All of the symptoms of sickle-cell disease result from the actions of just one allele.
D. Sickle-cell disease is common in tropical Africa.
E. About one in 10 African Americans is a carrier of sickle-cell disease.
B. White blood cells are sickle shaped in sickle-cell disease.
535
Which of the following terms refers to the situation where a single phenotypic characteristic is determined by the additive effects of two or more genes?
```
A. codominance
B. blending inheritance
C. incomplete dominance
D. pleiotropy
E. polygenic inheritance
```
E. polygenic inheritance
536
The chromosome theory of inheritance states that
A. humans have 46 chromosomes.
B. None of the choices are correct.
C. chromosomes that exhibit mutations are the source of genetic variation.
D. the behavior of chromosomes during mitosis accounts for inheritance patterns.
E. the behavior of chromosomes during meiosis and fertilization accounts for patterns of inheritance.
E. the behavior of chromosomes during meiosis and fertilization accounts for patterns of inheritance.
537
Genes located close together on the same chromosomes are referred to as __________ genes and generally __________.
A. linked . . . sort independently during meiosis
B. associated . . . sort independently during meiosis
C. homologous . . . are inherited together
D. linked . . . do not sort independently during meiosis
E. codependent . . . do not sort independently during meiosis
D. linked . . . do not sort independently during meiosis
538
Crossing over __________ genes into assortments of __________ not found in the parents.
```
A. recombines unlinked . . . chromosomes
B. combines linked . . . genes
C. recombines unlinked . . . genes
D. recombines linked . . . alleles
E. combines unlinked . . . alleles
```
D. recombines linked . . . alleles
539
Which of the following kinds of data could be used to map the relative position of three genes on a chromosome?
A. the frequencies with which the genes are inherited from the mother and from the father
B. the frequencies with which the genes exhibit incomplete dominance over each other
C. the frequencies of mutations in the genes
D. the frequencies with which the genes are heterozygous
E. the frequencies with which the corresponding traits occur together in offspring
E. the frequencies with which the corresponding traits occur together in offspring
540
What is the normal complement of sex chromosomes in a human male?
A. one X chromosome and one Y chromosome
B. two X chromosomes and one Y chromosome
C. two X chromosomes
D. two Y chromosomes
E. one Y chromosome
A. one X chromosome and one Y chromosome
541
How many sex chromosomes are in a human gamete?
```
A. two
B. three
C. four
D. five
E. one
```
E. one
542
A plant species in which individual plants produce both sperm and eggs is called
```
A. polyploid.
B. dioecious.
C. monoecious.
D. hermaphroditic.
E. pleiotropic.
```
C. monoecious.
543
An animal species in which an individual produces both eggs and sperm is called
```
A. pleiotropic.
B. polyploid.
C. monoecious.
D. dioecious.
E. hermaphroditic.
```
E. hermaphroditic.
544
How is sex determined in most ants and bees? Sex is determined by the
```
A. Z-W system.
B. X-Y system.
C. number of chromosome sets.
D. X-O system.
E. size of the sex chromosome.
```
C. number of chromosome sets.
545
What is meant by the statement that "male bees are fatherless"?
A. Male bees are produced by budding.
B. Male bees develop from fertilized eggs.
C. The queen bee's mate dies before the male eggs hatch.
D. Male bees develop from unfertilized eggs.
E. Male bees don't play a role in the rearing of bee young.
D. Male bees develop from unfertilized eggs
546
Any gene located on a sex chromosome
```
A. is called a recessive gene.
B. is called a dominant allele.
C. will exhibit codominance.
D. will exhibit pleiotropy.
E. is called a sex-linked gene.
```
E. is called a sex-linked gene.
547
Recessive sex-linked human conditions include which of the following?
```
A. muscular dystrophy
B. hemophilia
C. red-green color blindness
D. albinism
E. red-green color blindness, muscular dystrophy, and hemophilia
```
E. red-green color blindness, muscular dystrophy, and hemophilia
548
Why are sex-linked conditions more common in men than in women?
A. None of the choices are correct.
B. The sex chromosomes are more active in men than in women.
C. Men acquire two copies of the defective gene during fertilization.
D. Women simply do not develop the disease regardless of their genetic composition.
E. Men need inherit only one copy of the recessive allele for the condition to be fully expressed.
E. Men need inherit only one copy of the recessive allele for the condition to be fully expressed.
549
Who discovered the transforming factor (transformation)?
```
A. Griffith
B. Hershey-Chase
C. Beadle and Tatum
D. Watson and Crick
E. Chargaff
```
A. Griffith
550
Who proposed one gene- one protein?
```
A. Chargaff
B. Griffith
C. Beadle and Tatum
D. Hershey-Chase
E. Watson and Crick
```
C. Beadle and Tatum
551
Who discovered that the amount of A = T and C = G in any given sample of DNA?
```
A. Griffith
B. Watson and Crick
C. Chargaff
D. Beadle and Tatum
E. Hershey-Chase
```
C. Chargaff
552
The transfer of genetic information from DNA to RNA is called
```
A. translation.
B. initiation.
C. transcription.
D. elongation.
E. promotion.
```
C. transcription
553
Where do transcription and translation occur in prokaryotic cells?
```
A. in the nucleus
B. in the cell wall
C. in chromatophores
D. in the cytoplasm
E. on the plasma membrane
```
D. in the cytoplasm
554
Who gained credit for discovering the structure of DNA?
```
A. Hershey-Chase
B. Chargaff
C. Griffith
D. Watson and Crick
E. Beadle and Tatum
```
D. Watson and Crick
555
Who showed DNA was the genetic material and not protein?
```
A. Beadle and Tatum
B. Watson and Crick
C. Chargaff
D. Hershey-Chase
E. Griffith
```
D. Hershey-Chase
556
In replication of DNA, are the two new molecules identical (excluding mutations)?
A. No
B. Yes
B. Yes
557
What results from replication?
A. DNA
B. RNA
C. polypeptide
A. DNA
558
What results from translation?
A. RNA
B. polypeptide
C. DNA
B. polypeptide
559
The number of different amino acids found in protein.
A. 20
B. 50
C. 10
D. 5
A. 20
560
What base is found in DNA but not in RNA?
```
A. U
B. G
C. A
D. C
E. T
```
E. T
561
Which of the RNA molecules carries information as it is needed for the construction of a protein?
A. tRNA
B. rRNA
C. mRNA
D. primary RNA
C. mRNA
562
Which of the RNA molecules carries an amino acid to the ribosome?
A. tRNA
B. primary RNA
C. rRNA
D. mRNA
A. tRNA
563
Which of the RNA molecules with protein makes up the ribosome?
A. rRNA
B. mRNA
C. primary RNA
D. tRNA
A. rRNA
564
What part of the nucleotide differs from other nucleotides in a DNA strand?
A. Nitrogenous base
B. phosphate
C. every nucleotide is exactly the same
D. sugar
A. Nitrogenous base
565
What bases always pair with each other?
A. T-U, C-A
B. A-T, C -G
C. A- G, C- T
D. A-C, T- G
B. A-T, C -G
566
What base is found in RNA but not in DNA?
```
A. U
B. G
C. A
D. T
E. C
```
A. U
567
What molecules make up the backbone of the DNA?
A. sulfur and phosphate
B. nitrogenous base and phosphate
C. ribose and deoxyribose
D. deoxyribose and phosphate
D. deoxyribose and phosphate
568
How many bases are in a codon?
```
A. 1
B. 4
C. 5
D. 3
E. 2
```
D. 3
569
How many bases in an anticodon?
```
A. 5
B. 1
C. 3
D. 2
E. 4
```
C. 3
570
The codon is found on which RNA?
A. mRNA
B. primary RNA
C. rRNA
D. tRNA
A. mRNA
571
The anticodon is found on which RNA?
A. tRNA
B. rRNA
C. mRNA
D. primary RNA
A. tRNA
572
A single codon codes for how many amino acids?
```
A. 3
B. 2
C. 5
D. 4
E. 1
```
E. 1
573
What sugar is found in DNA?
A. ribose
B. deoxyribose
C. sucrose
D. glucose
B. deoxyribose
574
What subunits make up DNA and RNA?
A. sugar
B. phosphate
C. nitrogenous base
D. sugar, phosphate, and nitrogenous base
D. sugar, phosphate, and nitrogenous base
575
Which is larger?
A. RNA
B. DNA
C. both are the same size
B. DNA
576
This is the largest listed chemical and holds many types of information.
A. chromosome
B. RNA
C. polypeptide
D. gene
A. chromosome
577
This type of mutation has a greater potential to change more amino acids in the polypeptide chain
A. point mutations(base substitution)
B. frame shift mutation (base deletion)
B. frame shift mutation (base deletion)
578
What year did Meselson and Stahl publish their work?
A. 1950
B. 1953
C. 1957
D. 1962
C. 1957
579
What radioisotope did they use?
A. C14
B. C12
C. N14
D. N15
D. N15
580
15N is heavy or light?
A. heavy
B. light
A. heavy
581
The process of producing two daughter molecules of intermediate density that are half new (light) and half old (heavy) is …
A. semiconservative replication
B. conservative replication
C. dispersive replication
A. semiconservative replication
582
What percentage of molecules are intermediate after the first replication (first generation)?
```
A. 25%
B. 50%
C. 75%
D. 100%
E. 0%
```
D. 100%
583
What year did Meselson and Stahl publish their work?
A. 1950
B. 1953
C. 1957
D. 1962
C. 1957
584
What radioisotope did they use?
A. C14
B. C12
C. N14
D. N15
D. N15
585
15N is heavy or light?
A. heavy
B. light
A. heavy
586
The process of producing two daughter molecules of intermediate density that are half new (light) and half old (heavy) is …
A. semiconservative replication
B. conservative replication
C. dispersive replication
A. semiconservative replication
587
What percentage of molecules are intermediate after the first replication (first generation)?
```
A. 25%
B. 50%
C. 75%
D. 100%
E. 0%
```
D. 100%
