Chapter 4 Flashcards
(121 cards)
1
Q
All living organisms are made of one or more cells. This is one of the principles of:
a. genetic theory. [This is not a scientific theory.]]
b. prokaryotic theory.
c. evolutionary theory.
d. endosymbiotic theory.
e. cell theory.
A
cell theory.
2
Q
_____ are found in all metabolically active cells and are involved primarily in transporting materials within, into, and out of cells.
a. Mitochondria
b. Vacuoles
c. Lysosomes
d. Peroxisomes
e. Vesicles
A
Vesicles
3
Q
Mitochondria contain circular strands of _____, similar to that found in many prokaryotes.
a. DNA
b. carbon dioxide
c. cilia
d. flagella
e. hemoglobin
A
DNA
4
Q
Every cell on earth can be classified into one of which two categories?
a. prokaryotes and eukaryotes
b. bacteria and mammalian
c. unicellular and multicellular
d. reproductive and nonreproductive
e. archaea and prokaryotes
A
prokaryotes and eukaryotes
5
Q
The hydrophilic head of the cell membrane is composed of:
a. a glycerol linked to a phosphorus-containing molecule.
b. cellulose.
c. carbon-hydrogen chains.
d. enzymatic proteins.
e. cholesterol.
A
a glycerol linked to a phosphorus-containing molecule
6
Q
The most basic unit of any organism is the _____.
a. Cell
b. chromosome
c. nucleus
d. centriole
e. macromolecule
A
Cell
7
Q
The inner region of a plasma membrane’s phospholipid bilayer:
a. is void of water.
b. has a net negative charge.
c. has a high salt concentration.
d. stores hormones for future use.
e. contains the head regions of the phospholipid molecules.
A
is void of water
8
Q
The _____ membrane surrounds the nucleus and separates it from the cytoplasm.
a. cell
b. lipid
c. nuclear
d. cytosol
e. chromatin
A
nuclear
9
Q
Who coined the term “cell”?
a. Charles Darwin and Robert Hooke
b. Charles Darwin
c. Robert Hooke
d. Gregor Mendel
e. Gregor Mendel and Charles Darwin
A
Robert Hooke
10
Q
Drugs called beta-blockers do all of the following except:
a. reduce high blood pressure.
b. block signaling through adrenaline receptors.
c. reduce outward symptoms of anxiety.
d. prevent adrenaline from doing its job.
e. bind to the cytoplasmic (intracellular) side of a receptor protein.
A
bind to the cytoplasmic (intracellular) side of a receptor protein.
11
Q
Which statement properly describes the role of vacuoles?
a. Vacuoles are involved in nutrient storage as well as waste management for plants.
b. Vacuoles are empty sacs within a plant cell that simply provide structure.
c. Vacuoles help provide physical support to plants, allowing stems, flowers, and other plant parts to stand upright.
d. Vacuoles function to connect cells and enable communication and transport between them.
e. Vacuoles function as storage spaces and also play a role in plant nutrition, waste management, predator deterrence, reproduction, and physical support.
A
Vacuoles function as storage spaces and also play a role in plant nutrition, waste management, predator deterrence, reproduction, and physical support.
12
Q
Prokaryotes:
a. are multicellular.
b. are more complex than eukaryotes.
c. evolved after eukaryotes.
d. lack a plasma membrane.
e. lack a nucleus.
A
lack a nucleus
13
Q
Which cellular structure makes it possible for a cell to differ structurally and biochemically from its surroundings?
a. plasma membrane
b. cell wall
c. phospholipid
d. endoplasmic reticulum
e. nucleus
A
plasma membrane
14
Q
What are the three types of protein fibers that make up the cytoskeleton?
a. microtubules, intermediate filaments, and microfilaments
b. cilia, intermediate filaments, and microfilaments
c. large, intermediate, and small microfilaments
d. tubules, filaments, and flagella
e. There are actually four types of protein fibers that make up the cytoskeleton.
A
microtubules, intermediate filaments, and microfilaments
15
Q
Which statement about plasma membranes is true?
a. The molecules making up the plasma membrane are locked in place.
b. The molecules that make up the membrane are phospholipids.
c. The molecules that make up most of the plasma membrane are polar at their heads and tails.
d. It is composed of a single layer of phospholipids.
e. It is a rigid structure that protects the cell like a shell.
A
The molecules that make up the membrane are phospholipids.
16
Q
What allows the passage of small molecules between animal cells?
a. desmosomes
b. tight junctions
c. nucleoli
d. black holes
e. gap junctions
A
gap junctions
17
Q
Which statement is true about plant cell walls?
a. They are made largely from chitin.
b. They provide plant cells with incredible structural strength.
c. They serve to retain and degrade waste products.
d. They are the location of photosynthesis in plants.
e. They are filled with stroma.
A
They provide plant cells with incredible structural strength.
18
Q
List the molecules that perform important funtions within the plasma membrane
A
Receptor proteins, recognition protiens, transport proteins, membrane enzymes, cholesterol, carbohydrate (chains)
19
Q
Which of these is not considered a cell?
a. human egg
b. virus
c. bacteria
d. fish egg
e. squid neuron
A
Virus
20
Q
What is Tonicity
A
The level of solute concentration. Can be Isotonic, hypotonic, or hypertonic
21
Q
What is it called when solute concentrations are balanced
A
Isotonic
22
Q
Hypotonic
A
Less of the solute in the asked about area
23
Q
Hypertonic
A
More of the solute in the asked about area
24
Q
If the solution surrounding a cell contains the same amount of solute as the cytoplasm, the osmotic condition is said to be _____.
a. distilled
b. isotonic
c. concentrated
d. hypotonic
e. hypertonic
A
Isotonic
25
Prokaryotes can be sorted into two categories: bacteria and _____.
a. flagella
b. archaea
c. endosymbiont
d. eukaryotes
e. fungi
archaea
26
In passive transport:
a. ATP is required to move especially large molecules or ions across a cell membrane.
b. molecules move from an area of low concentration to an area of high concentration.
c. molecules move spontaneously from an area of high concentration to an area of low concentration.
d. a transport protein moves one molecule against the concentration gradient, while another molecule moves down its gradient.
e. ATP is required to move molecules against the concentration gradient.
molecules move spontaneously from an area of high concentration to an area of low concentration.
27
The tail portion of an individual phospholipid molecule:
a. is hydrophobic and polar.
b. is hydrophilic and nonpolar.
c. contains bonds with unequal sharing of electrons.
d. is hydrophobic and nonpolar.
e. is hydrophilic and polar.
is hydrophobic and nonpolar
28
What describes receptor-mediated endocytosis?
a. the ends of neural cells releasing neurotransmitters
b. sodium and potassium ions being pumped across a cell membrane
c. a liver cell recognizing and engulfing an LDL molecule
d. white blood cells engulfing an invading bacterium
e. chloride entering a trachea cell via a transport protein
a liver cell recognizing and engulfing an LDL molecule
29
Nearly all cell types contain:
a. bacteria.
b. eukaryotes.
c. cell walls.
d. genetic information.
e. chloroplasts.
genetic information.
30
What are the three types of endocytosis?
a. plasmocytosis, pinocytosis, and exocytosis
b. phagocytosis, pinocytosis, and receptor-mediated endocytosis
c. vesicles, LDL particles, and receptors
d. phagocytosis, pinocytosis, and exocytosis
e. vesicles, LDL particles, and HDL particles
phagocytosis, pinocytosis, and receptor-mediated endocytosis
31
Polar molecules and many charged molecules like water, ions, amino acids, and sugars pass across the membrane via:
a. facilitated diffusion.
b. exocytosis.
c. membrane transport.
d. endocytosis.
e. protein-mediated exchange.
facilitated diffusion.
32
What is the main difference between flagella and pili?
a. Pili are found in eukaryotes, whereas flagella are unique to prokaryotes.
b. A pilus is an appendage that is used for prokaryotic attachment to surfaces, whereas a flagellum helps the prokaryote move.
c. A pilus is used to help prokaryotes and eukaryotes move; a flagellum only helps prokaryotes move.
d. Both pili and flagella are the same thing, and the terms can be used interchangeably.
e. A flagellum is considered an appendage; a pilus is not.
A pilus is an appendage that is used for prokaryotic attachment to surfaces, whereas a flagellum helps the prokaryote move.
33
The transport of water across a membrane from a solution of lower solute concentration to a solution of higher solute concentration is best described as:
a. receptor-mediated transport.
b. facilitated diffusion.
c. osmosis.
d. active transport.
e. secondary active transport.
osmosis.
34
Which organelle contains a small circular loop of DNA?
a. nucleus
b. mitochondria
c. lysosomes
d. Golgi apparatus
e. smooth endoplasmic reticulum
mitochondria
35
What is not part of the endomembrane system?
a. the smooth endoplasmic reticulum
b. the rough endoplasmic reticulum
c. the cytoskeleton
d. the Golgi apparatus
e. ribosomes.
the cytoskeleton
36
Which structure is not found in a prokaryotic cell?
a. Lysosome
b. ribosome
c. cell wall
d. flagellum
e. cytosol
Lysosome
37
Which characteristic is unique to eukaryotic cells?
a. presence of a plasma membrane
b. presence of a cell wall
c. presence of membrane-bound organelles
d. presence of ribosomes
e. presence of DNA
presence of membrane-bound organelles
38
Mitochondria need large amounts of oxygen to produce energy for our cells. In humans, mitochondria consume roughly _____ of the oxygen we breathe.
a. 45%
b. 55%
c. 100%
d. 80%
e. 70%
80%
39
What is found in both prokaryotic and eukaryotic cells?
a. peroxisome
b. lysosome
c. nucleolus
d. centriole
e. ribosome
ribosome
40
Which characteristics support the theory that mitochondria and chloroplasts were once independent prokaryotic cells?
a. Mitochondria and chloroplasts are membrane-bound organelles.
b. Mitochondria and chloroplasts store proteins.
c. Mitochondria and chloroplasts both have small, circular pieces of DNA.
d. Mitochondria and chloroplasts are both found in plant cells.
e. Mitochondria and chloroplasts both produce energy for the cell.
Mitochondria and chloroplasts both have small, circular pieces of DNA.
41
Which statement about chloroplasts is true?
a. Chloroplasts are found in eukaryotic cells, therefore they contain linear DNA.
b. The stacks of interconnected sacs within the chloroplast are known as thylakoids; the light-collecting for photosynthesis occurs here.
c. The chloroplast has one single membrane layer due to its small size.
d. The DNA of the chloroplast is found within the thylakoid sacs.
e. The stacks of interconnected sacs within the chloroplast are known as stroma; this is where the light-collecting for photosynthesis occurs.
The stacks of interconnected sacs within the chloroplast are known as thylakoids; the light-collecting for photosynthesis occurs here.
42
How long ago did eukaryotic cells evolve?
a. 3.5 billion years ago
b. 4.5 billion years ago
c. 2 billion years ago
d. 2 million years ago
e. 6,000 years ago
2 billion years ago
43
The cytoskeleton:
a. gives plant cells shape and support.
b. produces no force and is unrelated to cell movement.
c. controls the extracellular traffic flow.
d. gives animal cells shape and support.
e. only exists within prokaryotes, not eukaryotes.
gives animal cells shape and support.
44
Which statement about the nucleus is false?
a. The nucleus consists of two bilayers, layered one on top of the other.
b. The nucleus contains pores that only open in response to DNA entering or exiting the cell.
c. The nucleus contains three important structural components: the nuclear membrane, chromatin, and the nucleolus.
d. The nucleus acts as the genetic control center of the cell, directs all cellular activity, and stores hereditary information.
e. Ribosomes are assembled inside of the nucleus.
The nucleus contains pores that only open in response to DNA entering or exiting the cell.
45
Within the nucleus, an organism's genetic information can be found organized into a bundle of DNA fibers and proteins called the _____.
a. nucleolus
b. ribosomes
c. nuclear envelope
d. cytosol
e. chromatin
chromatin
46
Cilia:
a. are microfilament-based structures.
b. play a major role in cell division.
c. are long projections.
d. when they are present, occur in small numbers on a single cell.
e. help the cell move through its environment.
help the cell move through its environment.
47
Which statement is true?
a. Cell theory only applies to prokaryotic cells.
b. Only prokaryotic cells arose from preexisting cells.
c. Cell theory only applies to eukaryotic cells.
d. Both prokaryotic and eukaryotic cells arose from preexisting living cells.
e. Only eukaryotic cells arose from preexisting living cells.
Both prokaryotic and eukaryotic cells arose from preexisting living cells.
48
Which statement about the endoplasmic reticulum and the Golgi apparatus is true?
a. The Golgi apparatus is connected to the endoplasmic reticulum via tight junctions.
b. The Golgi apparatus is a site of processing and packaging only; the endoplasmic reticulum is responsible for synthesizing compounds such as carbohydrates.
c. Both the Golgi apparatus and the endoplasmic reticulum work together to form the endocytotic and exocytotic cycles of the cell.
d. Not all eukaryotic cells contain an endomembrane system; only those involved in transporting materials possess this system.
e. Both the Golgi apparatus and the endoplasmic reticulum work together to form the endomembrane system.
Both the Golgi apparatus and the endoplasmic reticulum work together to form the endomembrane system.
49
The most basic unit of any organism is the cell. What is meant by this phrase?
a. All organisms are made of many cells that perform their own unique functions.
b. All cells are invisible to the naked eye.
c. Every cell contains a unique set of genetic material that distinguishes it from other cells in the organism.
d. A cell cannot be divided any further without losing its properties as an element.
e. The cell is the smallest unit of any organism that can perform all of the necessary functions of life.
The cell is the smallest unit of any organism that can perform all of the necessary functions of life.
50
Which statement about eukaryotes is false?
a. Eukaryotes contain a membrane-bound nucleus.
b. Both eukaryotes and prokaryotes contain ribosomes.
c. Both eukaryotes and prokaryotes contain DNA.
d. Plant cells contain both mitochondria and chloroplasts.
e. All eukaryotes are multicellular.
All eukaryotes are multicellular.
51
What feature of chloroplasts suggests that they are derived from photosynthetic bacteria?
a. They are filled with stroma.
b. They have a nucleus.
c. They contain circular DNA.
d. They contain a central vacuole.
e. They contain thylakoids.
They contain circular DNA.
52
Which part of the endomembrane system is incorrectly matched with its function?
a. smooth ER; detoxifying waste products
b. rough ER; folding and packaging proteins
c. rough ER; delivering molecules from the golgi apparatus to the plasma membrane
d. smooth ER; synthesis of lipids
e. golgi apparatus; processing and packaging molecules to leave the cell
rough ER; delivering molecules from the golgi apparatus to the plasma membrane
53
What major advantage does the presence of organelles offer eukaryotic cells?
a. They make eukaryotic cells stronger.
b. They separate chemicals into different compartments, concentrating them for certain reactions.
c. They help make eukaryotic cells larger.
d. They greatly simplify eukaryotic cells, making them less complex.
e. They help to blend together the chemicals throughout the cell.
They separate chemicals into different compartments, concentrating them for certain reactions.
54
How long ago did prokaryotic cells evolve?
a. 3.5 billion years ago
b. 4.5 billion years ago
c. 2 billion years ago
d. 2 million years ago
e. 6,000 years ago
3.5 billion years ago
55
What is the difference between endosymbiosis and invagination?
a. Endosymbiosis involves the plasma membrane folding in on itself, whereas invagination refers to engulfment of another cell.
b. Endosymbiosis is the best current theory for the origin of ribosomes.
c. Endosymbiosis pertains to compatible organisms, whereas invagination refers to a relationship among completely different organisms.
d. Endosymbiosis refers to the engulfment of a prokaryotic cell that developed into an organelle, whereas invagination refers to the membrane folding in on itself and forming membranous organelles.
e. Endosymbiosis pertains to organelle evolution, whereas invagination refers to a mechanism by which organisms obtain food from their surroundings.
Endosymbiosis refers to the engulfment of a prokaryotic cell that developed into an organelle, whereas invagination refers to the membrane folding in on itself and forming membranous organelles.
56
The cell organelles most analogous (comparable) to mitochondria are:
a. lysosomes.
b. peroxisomes.
c. the Golgi apparatus.
d. chloroplasts.
e. ribosomes.
chloroplasts.
57
Proliferation of the smooth ER is likely in an individual who:
a. is addicted to prescription painkillers.
b. works outdoors in a cold temperatures.
c. lacks rough ER in their cells.
d. has just started lifting weights.
e. is training to run a marathon.
is addicted to prescription painkillers.
58
Plants wilt due to a lack of water because the shrinkage of their _____ results in a loss of turgor pressure.
a. lysosomes
b. cell walls
c. chloroplasts
d. vesicles
e. vacuoles
vacuoles
59
You are given two microscope slides, one containing a section of animal tissue and the other containing a section of plant tissue. Which structure could you look for to tell them apart?
a. the presence or absence of a plasma membrane
b. the presence or absence of a cell wall
c. the presence or absence of a nucleus
d. the presence or absence of smooth endoplasmic reticulum
e. the presence or absence of mitochondria
the presence or absence of a cell wall
60
The transport of large molecules out of the cell, across the membrane, is accomplished via:
a. active transport.
b. endocytosis.
c. passive transport.
d. facilitated diffusion.
e. exocytosis.
exocytosis.
61
Which is not one of the primary functions of the cytoskeleton?
a. initiating the process of cell division
b. controlling intercellular traffic
c. giving cells their shape
d. giving cells support
e. allowing cells to move
initiating the process of cell division
62
Under endosymbiotic theory, both mitochondria and chloroplasts are thought to have been independent _____.
a. Prokaryotes
b. proteins
c. nuclei
d. eukaryotes
e. ribosomes
Prokaryotes
63
Which function would be performed by a transport protein in the cell membrane?
a. moving testosterone produced within a testicular cell into the bloodstream
b. initiation of an immune system response upon identifying a foreign cell
c. recognizing and ingesting a cold virus
d. binding to adrenaline on heart cells, thereby increasing the heart's rate of contraction
e. maintaining the flexibility of the cell membrane
moving testosterone produced within a testicular cell into the bloodstream
64
Which statement about chloroplasts and mitochondria is false?
a. Mitochondria break down food energy to make ATP.
b. Chloroplasts produce food from sunlight energy.
c. Both mitochondria and chloroplasts are involved with energy transformation.
d. Animal cells do not contain chloroplasts.
e. Plants have chloroplasts instead of mitochondria.
Plants have chloroplasts instead of mitochondria.
65
Invagination is a theory that helps to explain:
a. how prokaryotes evolved a cell membrane.
b. where mitochondria came from.
c. where chloroplasts came from.
d. how some membrane-bound organelles formed in eukaryotes.
e. how DNA is replicated.
how some membrane-bound organelles formed in eukaryotes.
66
_________ helps the plasma membrane maintain it’s flexibility, preventing the membrane from becoming too fluid or floppy at moderate temperatures or rigid at freezing temperatures.
a. Polarity
b. The bilayer
c. Cholesterol
d. Plasma
Cholesterol
67
Membrane enzymes
a. Bind to chemicals in the cell’s external environment and helps communicate information from the outside to the inside of the cell
b. Accelerate chemical reactions on the plasma membrane’s surface
c. Serve as part of the membrane’s fingerprint and helps cells bind to other cells or molecules
d. Assist polar or charged substances pass through the plasma membrane
Accelerate chemical reactions on the plasma membrane’s surface
68
Membrane enzymes
a. Are surface proteins
b. Are transmembrane proteins
c. Are either surface membrane or transmembrane proteins
Are either surface membrane or transmembrane proteins
69
Transport proteins
a. Assist polar or charged substances pass through the plasma membrane
b. Accelerate chemical reactions on the plasma membrane’s surface
c. Serve as part of the membrane’s fingerprint and helps cells bind to other cells or molecules
d. Bind to chemicals in the cell’s external environment and helps communicate information from the outside to the inside of the cell
Assist polar or charged substances pass through the plasma membrane
70
Transport proteins
a. Are surface proteins
b. Are transmembrane proteins
c. Are either surface membrane or transmembrane proteins
Are transmembrane proteins
71
Recognition proteins
a. Bind to chemicals in the cell’s external environment and helps communicate information from the outside to the inside of the cell
b. Serve as part of the membrane’s fingerprint and helps cells bind to other cells or molecules
c. Assist polar or charged substances pass through the plasma membrane
d. Accelerate chemical reactions on the plasma membrane’s surface
Serve as part of the membrane’s fingerprint and helps cells bind to other cells or molecules
72
Recognition proteins
a. Are surface proteins
b. Are transmembrane proteins
c. Are either surface membrane or transmembrane proteins
Are either surface membrane or transmembrane proteins
73
Receptor proteins
a. Accelerate chemical reactions on the plasma membrane’s surface
b. Bind to chemicals in the cell’s external environment and helps communicate information from the outside to the inside of the cell
c. Assist polar or charged substances pass through the plasma membrane
d. Serve as part of the membrane’s fingerprint and helps cells bind to other cells or molecules
Bind to chemicals in the cell’s external environment and helps communicate information from the outside to the inside of the cell
74
Receptor proteins
a. Are surface proteins
b. Are transmembrane proteins
c. Are either surface membrane or transmembrane proteins
Are either surface membrane or transmembrane proteins
75
What is the plasma membrane made of?
Phospholipids
76
Thin, flexible, two-layered membrane that holds the contents of a cell in place and regulates what enters and leaves the cell
plasma membrane
77
What three parts does the nucleus consist of?
Nuclear membrane, chromatin, and the nucleolus
78
Cystic fibrosis is a disease that affects the transmembrane protein that controls the flow of ____ into and out of the cells found primarily in the ____.
a. Water; sinuses and salivary glands
b. Hydrogen ions; blood vessels and arteries
c. Chloride ions; lungs and digestive tract
d. Cholesterol; liver and kidneys
Chloride ions; lungs and digestive tract
79
Which CD marker does HIV target?
a. CD1
b. CD2
c. CD3
d. CD4
CD4
80
Where are CD4 markers located?
a. in all areas of the body
b. deep within the body
c. on the surface of the body
deep within the body
81
What are the three primary connections between animal cells?
a. Tight junctions, desmosomes, and gap junctions
b. Microtubules, intermediate filaments, and microfilaments
c. Large, intermediate, and small microfilaments
d. Cilia, flagella, and pili
Tight junctions, desmosomes, and gap junctions
82
Tight junctions
a. Form water tight seals and anchor cells in place.
b. Are pores surrounded by special proteins the form open channels between two cells
c. Act like Velcro to fasten cells together in long sheets
Form water tight seals and anchor cells in place.
83
Gap junctions
a. Form water tight seals and anchor cells in place.
b. Are pores surrounded by special proteins the form open channels between two cells
c. Act like Velcro to fasten cells together in long sheets
Are pores surrounded by special proteins the form open channels between two cells
84
Desmosomes
a. Form water tight seals and anchor cells in place.
b. Are pores surrounded by special proteins the form open channels between two cells
c. Act like Velcro to fasten cells together in long sheets
Act like Velcro to fasten cells together in long sheets
85
When the molecular movement occurs spontaneously, without the input of energy, the process is called _________.
a. Intercellular trasnport
b. Active transport
c. Passive transport
d. Extracellular transport
Passive transport
86
A difference in the concentration of solutes in two areas is called a(n)
a. Imbalance
b. Solvent
c. Concentration gradient
d. Active transport
concentration gradient
87
In cells, molecules that are ________ and carry ________ can pass directly through the phospholipid bilayer of the membrane
a. Large; no charge
b. Small; positive charges
c. Large; negative charges
d. Small; no charge
Small; no charge
88
____ into and out of cells may be necessary if molecules or ions are very large or are being moved against their concentration gradient.
Active transport
89
The type of active transport that occurs when energy from ATP is used to fuel the transport of molecules
primary active transport
90
Digestion is an example of
primary active transport
91
The transport protein simultaneously moves one molecule against its concentration gradient while letting a second type of molecule flow down its concentration gradient
secondary active transport
92
Many substances are just too big to get into or out of a cell by passive or active transport. To absorb large particles, such as bacterial invaders, cells engulf them with their plasma membrane in a process called ____ .
endocytosis
93
To export large particles, such as digestive enzymes manufactured for use elsewhere in the body, cells often use the process of____.
exocytosis
94
During endocytosis the ____ oozes around an object outside the cell, surrounding it, and forms a pocket-like sac called a ____.
plasma membrane; vesicle
95
Phagocytosis means ____. The vesicle is ____ than that of a pinocytosis vesicle.
eat; larger
96
Pinocytosis means ____. The vesicle is ____ than that of a phagocytosis vesicle.
drink; smaller
97
In ____, receptor molecules on the surface of a cell recognize and bind one specific type of molecule. When the appropriate molecule binds to each of the receptor proteins, the membrane begins to fold inward, first forming a little pit and then eventually completely engulfing the molecules, which are still attached to their receptors.
receptor-mediated endocytosis
98
Molecules can be moved out of a cell by ____, in which a vesicle inside the cell fuses with the plasma membrane and dumps its contents outside the cell.
exocytosis
99
All of these are true about the cytoskeleton except
a. The intracellular traffic is controlled by the cytoskeleton
b. The cytoskeleton gives the cell shape and support
c. The cytoskeleton is only present in animal cells
d. Cells are given some ability to control their movement due to the force generated by the cytoskeleton
The cytoskeleton is only present in animal cells
100
____ are durable, rope-like systems of numerous different overlapping proteins.
Intermediate filaments
101
____ linear fibers made from repeating units of protein and look like rigid, hollow tubes.
Microtubules
102
____ are long, solid, rod-like fibers help generate forces, including those important in cell contraction and cell division.
Microfilaments
103
In Tay-Sachs disease, a genetic mutation causes a malfunction in a certain organelle that leads to a backup of molecules and proteins, ultimately interfering with the entire functioning of the cell. Which organelle is primarily affected by this disease?
a. endoplasmic reticulum
b. peroxisomes
c. Golgi apparatus
d. lysosomes
e. nucleus
lysosomes
104
Which is not considered to be a prokaryote?
a. an E. coli cell
b. an archaean
c. a bacterium
d. a virus
e. an S. pyogenes cell
a virus
105
Which statement in regard to lysosomes is false?
a. Many immune cells have large numbers of lysosomes because they have to dispose of by-products of disease-causing organisms.
b. Individuals with Tay-Sachs disease lack a key enzyme that makes it impossible for lysosomes to carry out their primary function.
c. In addition to animal cells, lysosomes exist in plant cells.
d. After lysosomes break down wastes into their component parts, those materials are released back into the cell's cytoplasm, where they can be reused.
e. Lysosomes are membrane-enclosed vesicles that contain super-basic fluid and digestive enzymes.
Lysosomes are membrane-enclosed vesicles that contain super-basic fluid and digestive enzymes.
106
Suppose the Golgi apparatus were destroyed in a plant cell but all other functions remained. What would be immediately true of this cell?
a. It no longer could make sugar from carbon dioxide, water, and sunlight.
b. It no longer could synthesize proteins.
c. It no longer could produce lipids
d. It no longer could modify and package proteins for delivery.
e. It no longer could retain its shape, and would collapse on itself
It no longer could modify and package proteins for delivery.
107
Diffusion across the cell's outer membrane:
a. is also called dynamic equilibrium.
b. never occurs; all molecules cross the membrane within protein carriers.
c. occurs without the input of energy.
d. requires ATP.
e. always results in the movement of molecules from areas of low concentration to areas of high concentration.
occurs without the input of energy.
108
Cystic fibrosis is the result of which type of faulty plasma membrane molecule?
a. recognition proteins
b. cholesterol
c. ion channel
d. receptor protein
e. membrane enzymes
ion channel
109
According to the endosymbiotic theory, which inference can be made?
a. Ancestrally, human cells are likely evolved from prokaryotes which engulfed other, smaller prokaryotes.
b. An ancestral prokaryote engulfed a eukaryote, therefore eukaryotes and prokaryotes are not as different as they seem.
c. The simplicity of prokaryotes is in part due to eukaryotic engulfment.
d. The plasma membrane is capable of folding on itself.
e. Chloroplasts and mitochondria are originally eukaryotes but prokaryotic engulfment caused them to convert to prokaryotes.
Ancestrally, human cells are likely evolved from prokaryotes which engulfed other, smaller prokaryotes.
110
A deer is grazing on some hillside shrubs. It bites into the leaves of one plant and immediately spits it out because it tastes bad. Which cellular component saved the plant from being eaten down to its roots by the deer?
a. the smooth endoplasmic reticulum, which manufactures strongly acidic lipids like fatty acids
b. the lysosome, which contains corrosive enzymes that would irritate the deer's mouth and tongue
c. the central vacuole, which stores nasty-tasting materials
d. the mitochondria, which manufacture highly alkaline ATP
e. the chloroplast, which can quickly produce fermented sugars that are extremely sour
the central vacuole, which stores nasty-tasting materials
111
Invagination is a theory that helps to explain:
a. how prokaryotes evolved a cell membrane.
b. how DNA is replicated.
c. how some membrane-bound organelles formed in eukaryotes.
d. where chloroplasts came from.
e. where mitochondria came from.
how some membrane-bound organelles formed in eukaryotes.
112
Which statement about passive transport across the cell membrane is incorrect?
a. Diffusion along a concentration gradient is one form of passive transport.
b. Facilitated diffusion by transport proteins is one form of passive transport.
c. Osmosis is one form of passive transport.
d. Passive transport may involve chemical energy in the form of ATP.
e. Osmosis that occurs through aquaporins is not considered passive transport.
Passive transport may involve chemical energy in the form of ATP.
113
Which statement is true?
a. Animal cells contain ribosomes, but like prokaryotic cells, plant cells do not.
b. The most recent common ancestor of animal cells and plant cells was prokaryotic.
c. Centrioles are generally not found in plant cells, and chloroplasts, cell walls, and vacuoles are not found in animal cells.
d. Animal cells and plant cells are entirely different types of cells, not even sharing a common ancestor.
e. Centrioles are structures always found in plant and animal cells.
Centrioles are generally not found in plant cells, and chloroplasts, cell walls, and vacuoles are not found in animal cells.
114
Plants wilt due to a lack of water because the shrinkage of their _____ results in a loss of turgor pressure.
a. chloroplasts
b. vesicles
c. vacuoles
d. cell walls
e. lysosomes
vacuoles
115
Which statement about cellular "fingerprints" is false?
a. Cellular fingerprints are identical among parents, children, and siblings.
b. It is difficult to transplant an organ from one individual to another because of cellular fingerprints.
c. Cellular fingerprints are how the immune system recognizes and attacks foreign invaders.
d. Cellular fingerprints explain why a person can't catch HIV from shaking hands.
e. HIV uses cellular fingerprints to target and infect a person's cells.
Cellular fingerprints are identical among parents, children, and siblings.
116
Are vacuoles found in plant cells or animal cells?
Plant cells
117
Which membrane molecule is correctly matched to its function?
a. receptor protein: helps the plasma membrane retain flexibility
b. recognition protein: provides a passageway that allows polar or charged substances to pass through the plasma membrane
c. cholesterol: binds to external chemicals in order to regulate processes within the cell
d. carbohydrate chains: provide a "fingerprint" for the cell so it can be identified by other cells
e. transport proteins: catalyze intra- and extracellular reactions on the plasma membrane
carbohydrate chains: provide a "fingerprint" for the cell so it can be identified by other cells
118
In an experiment, you measure the concentration of a polar molecule inside and outside a cell. You find that the concentration is high and gradually increasing inside the cell. You also measure the ATP concentration inside the cell and find that it is dropping. What is your best hypothesis for the process you are observing?
a. passive transport
b. facilitated diffusion
c. exocytosis
d. simple diffusion
e. active transport
active transport
119
Modern airplanes are built with waterproof seals around the windows and rivets are used to hold the metal sheets to the frame, forming the fuselage. The waterproof seals are to rivets as _____ are to _______.
a. plasmodesmata; gap junctions
b. tight junctions; desmosomes
c. desmosomes; plasmodesmata
d. gap junctions; tight junctions
e. desmosomes; tight junctions
tight junctions; desmosomes
120
You are studying a single-celled organism under a microscope. It does not have a cell wall or chloroplasts. After staining the cell, you can clearly see that its genetic material is contained within an internal membrane, suspended in the cytoplasm. You can identify a flagella. What type of cell is this most likely to be?
a. a protist, because it has a nucleus and is unicellular
b. an animal cell, because it has a nucleus and is unicellular
c. a prokaryote, because it is unicellular
d. a plant cell, because it lacks a cell wall
e. a prokaryote, because of its flagella
a protist, because it has a nucleus and is unicellular
121
Which cell connection is incorrectly matched with its location in living organisms?
a. desmosomes: body cavity lining
b. tight junctions: small intestines
c. lysosomes: nerve cells
d. gap junctions: cardiac tissue
e. desmosomes: muscle tissue
lysosomes: nerve cells
