Midterm 1 Review Flashcards
Cell Theory and Germ Theory are considered theories, rather than hypotheses, because:
a
Hypotheses offer an explanation of a phenomenon, whereas theories do not
b
Theories are well-supported by evidence
c
Hypotheses must be testable and falsifiable, whereas theories do not
d
Two of the above are true
e
All of the above are true
B: Theories are well-supported by evidence
Which of the following is true, concerning observational studies?
a
All other things being equal, observational studies tend to yield more trustworthy results than do experimental studies
b
One example of an observational study was the study described in lecture of scientists giving one group of people echinacea and giving another group of people a placebo pill, after both groups had been exposed to the cold virus. (The purpose of the study being to see if taking echinacea had an effect on cold symptoms)
c
It is easier to control for confounding variables in observational studies than in experimental studies
d
Observational studies tend to take longer and be more expensive than experimental studies
e
All of the above are false
e
All of the above are false
One of your friends, Krieger, is a scientist. He has noticed that people that have been infected with a specific virus, SMAM-1, tend to weigh more than people that have not been infected by this virus in the past. He hopes to support his hypothesis that SMAM-1 infection leads to obesity by doing an experimental study infecting mice with SMAM-1. He decides to inject the virus into 10 mice and to not inject it into another 10 mice. With each group, he will measure the weight of the mice over the course of each mouse’s lifetime to see if mice infected with SMAM-1 gain more weight than ones that were not infected.
All of the following are potential confounding variables that Krieger should try to control for in his experiment, except:
a
The amount of exercise that each group gets
b
The amount of food eaten by each group
c
The sex of the mice in each group
d
The mice in the second group are stuck with a needle while the mice in the first group are not
e
All of the above are potential confounding variables
e
All of the above are potential confounding variables
One of your friends, Krieger, is a scientist. He has noticed that people that have been infected with a specific virus, SMAM-1, tend to weigh more than people that have not been infected by this virus in the past. He hopes to support his hypothesis that SMAM-1 infection leads to obesity by doing an experimental study infecting mice with SMAM-1. He decides to inject the virus into 10 mice and to not inject it into another 10 mice. With each group, he will measure the weight of the mice over the course of each mouse’s lifetime to see if mice infected with SMAM-1 gain more weight than ones that were not infected.
Which of the following is not an example of how the study could be improved for more reliable results?
a
Adding a placebo injection instead of simply not injecting the control group
b
Making sure that the cages of each mouse are clearly labeled as “SMAM-infected” or “control,” so that Krieger know exactly which mouse is in each group at all times
c
Controlling for environmental variables, such as the amount of light each mouse is exposed to and the temperature of the room
d
Adding more mice to both the injected group and the group that are not injected. For example, having each group include 50 mice, instead of 10 mice.
e
All of the above would improve the reliability of Krieger’s results
b
Making sure that the cages of each mouse are clearly labeled as “SMAM-infected” or “control,” so that Krieger know exactly which mouse is in each group at all times
HDL and LDL are relatively large, combined clumps of both protein and lipid molecules that circulate in the blood of mammals. They act as suitcases to move cholesterol, fatty acid remnants, triglycerides, and phospholipids from one place to another through the bloodstream (LDL recirculates lipids throughout the body, whereas HDL takes lipids to the liver to excrete them in feces.) Given that lipids are non-polar and proteins are most often polar, which of the following statements is likely correct?
a
The lipid portion of LDL does not dissolve in the bloodstream, while the lipid portion of HDL does dissolve
b
The protein portions of both LDL and HDL can interact with water molecules in the bloodstream
c
Neither the protein nor the lipid portions of LDL molecules likely interact with the water molecules in the bloodstream
d
Both the protein and lipid portions of HDL molecules likely interact with the water molecules in the bloodstream
b
The protein portions of both LDL and HDL can interact with water molecules in the bloodstream
Which of the following is true of carbon?(select all that apply)
a
It almost always forms a total of four covalent bonds
b
It can form polar or nonpolar bonds
c
It can only form single bonds with other atoms, not double or triple bonds
d
When carbon forms bonds with oxygen, those bonds tend to store less energy than bonds that carbon forms with hydrogen
e
All of the above are true
a
It almost always forms a total of four covalent bonds
b
It can form polar or nonpolar bonds
d
When carbon forms bonds with oxygen, those bonds tend to store less energy than bonds that carbon forms with hydrogen
Water has a high capacity to resist changes in temperature because of the:
a
ionic bonds formed between the hydrogens of water molecules and the oxygens of nearby water molecules
b
hydrogen bonds formed between the hydrogens of water molecules and the oxygens of nearby water molecules
c
nonpolar covalent bond formed between the oxygen and a hydrogen of a single water molecule
d
covalent bonds formed between the hydrogens of water molecules and the oxygens of nearby water molecules
e
Van der Waals interactions between adjacent water molecules
b
hydrogen bonds formed between the hydrogens of water molecules and the oxygens of nearby water molecules
You are about to embark on a long day of hiking and you want to eat something that will give you a long, sustained release of energy throughout the day, instead of something that will only give a short burst of energy. Thinking specifically about carbohydrates, which of the following foods would be the best for you to eat for this purpose?
a
Food with a lot of disaccharides - such as candy (lots of sucrose)
b
Food with a lot of monosaccharides - such as orange juice (lots of fructose)
c
Food with a lot of starch - such as oatmeal
d
Food with a lot of cellulose - such as lettuce
c
Food with a lot of starch - such as oatmeal
Which of the following statements about cellulose is false?
a
Cellulose and starch are both made of many glucose molecules bonded together with glycosidic linkages
b
Cellulose has a different three-dimensional structure from starch, making it so that an enzyme that can break down starch cannot also break down cellulose
c
Cellulose is used as a structural component in plant cells
d
Cellulose is labeled as “dietary fiber” on nutrition labels
e
All of the above statements about cellulose are true
e
All of the above statements about cellulose are true
Which of the following are polysaccharides?
a
cellulose
b
lactose
c
glycogen
d
starch
e
peptidoglycan
c
glycogen
d
starch
e
peptidoglycan
a
cellulose
Which of the following is not a polysaccharide?
a
cellulose
b
lactose
c
glycogen
d
starch
e
peptidoglycan
b
lactose
Where would amino acids with nonpolar R-groups most likely be found within the overall structure of a folded protein, such as this chymotrypsin enzyme?
a
Nonpolar and polar groups cannot coexist in the same protein structure.
b
Amino acids with nonpolar R groups would be found in the interior of chymotrypsin.
c
Amino acids with nonpolar R groups would be found on the exterior of chymotrypsin
d
Nonpolar and polar groups would be equally distributed among the series of amino acids in chymotrypsin.
e
There is no way to predict where a nonpolar group or a polar group would be in any protein structure
b
Amino acids with nonpolar R groups would be found in the interior of chymotrypsin.
You disrupt all hydrogen bonds in a protein. What level of structure will still be preserved?
a
Tertiary
b
Primary
c
Quaternary
d
Secondary
e
None - every level of protein structure involves hydrogen bonds
b
Primary
Which of the following is false of proteins?
a
The shape of a protein is largely dependent on the sequence of amino acids in that protein
b
The peptide bonds that bind amino acids together are weak and flexible in comparison with most other covalent bonds in the protein’s structure
c
Proteins have many functions in the body, including transportation of molecules across membranes and contraction of muscles
d
A person who does not consume essential amino acids will not be able to build all of the proteins that they normally would be able to
e
One of the primary dangers of fevers is that the increase in temperature may cause the denaturation of proteins, which usually leads to the loss of function of those proteins
b
The peptide bonds that bind amino acids together are weak and flexible in comparison with most other covalent bonds in the protein’s structure
What would happen to DNA molecules treated with enzymes that break hydrogen bonds?
a
The two strands of the double helix would separate
b
The phosphodiester linkages between the nucleotides of the backbone would be broken
c
Both A and B would occur
d
Neither A nor B would occur
e
A would happen, but B is incorrect because nucleotides are held together by glycosidic linkages, not by phosphodiester bonds
a
The two strands of the double helix would separate
