WorksheetsBio Units 1-8 College Board
Total questions: 204
Worksheet time: 2hrs 42mins
Name
Class
Date
1.
Which feature of model 1 best illustrates how biological information is coded in a DNA molecule?
a)
The 5' and 3' labels at the ends of each strand
b)
The labeling of the hydrogen bonds between base pairs
c)
The lines connecting sugars and phosphate groups that represent covalent bonds
d)
The linear sequence of the base pairs
2.
Figure 1 represents a segment of DNA . Radiation can damage the nucleotides in a DNA molecule. To repair some types of damage, a single nucleotide can be removed from a DNA molecule and replaced with an undamaged nucleotide. Which of the four labeled bonds in Figure 1 could be broken to remove and replace the cytosine nucleotide without affecting the biological information coded in the DNA molecule?
a)
Bond X only
b)
Bond W only
c)
Bonds Y and Z at the same time
d)
Bonds W and Z at the same time
3.
A student wants to modify model 1 so that it represents an RNA double helix instead of a DNA double helix. Of the following possible changes, which would be most effective in making model 1 look more like RNA than DNA?
a)
Changing the sequence of the base pairs
b)
Changing the deoxyriboses to riboses by adding -OH groups
c)
Changing the shapes of the nitrogenous bases to match those shown in model 2
d)
Changing the sugar-phosphate backbone to a ribbon, as shown in model 3
4.
Based on Figure 1, which of the following best compares the atomic structures of starch and cellulose?
a)
Starch is composed of carbon, hydrogen, and oxygen, while cellulose also contains nitrogen.
b)
Starch and cellulose are composed of repeating glucose monomers; however, in cellulose every other glucose monomer is rotated 180 degrees.
c)
Starch is composed of monomers that each have a CH2OH group, while cellulose only has a CH2OH group on every other monomer.
d)
Starch and cellulose are composed of identical monomers and therefore have identical structures.
5.
Which of the following statements best describes the different functions of starch and cellulose in plants?
a)
The differences in the assembly and organization of the monomers of these two polymers result in different chemical properties.
b)
Since starch and cellulose are composed of identical monomers, the cellular environment where they are located controls their function.
c)
The monomers of cellulose are connected by covalent bonds, making it idea for structural support.
d)
The monomers of starch are connected by ionic bonds, making it ideal for energy storage for plants.
6.
Which of the following best describes the process that adds a monosaccharide to an existing polysaccharide?
a)
The monosaccharide is completely broken down by a specific enzyme and then the atoms are reorganized and made into a polysaccharide.
b)
Ionic bonds are formed between adjacent carbon atoms of the monosaccharide and the polysaccharide by adding water (H2O) and a specific enzyme.
c)
A specific enzyme removes the hydrogen (H) from the monosaccharide and the hydroxide (OH) from the polysaccharide, creating a bond between the two and creating a water (H2O) molecule
d)
A specific enzyme removes two hydroxides (OH) , one from the monosaccharide, and one from the polysaccharide, creating a bond between the two monosaccharides and creating a hydrogen peroxide (H2O2) ) molecule.
7.
Which of the following would most likely occur if cattle lost the ability to maintain a colony of microorganisms in their digestive tract?
a)
Cattle would no longer be able to synthesize cellulose.
b)
Cattle would have to convert cellulose to starch before digesting it.
c)
Cattle would have to start producing enzyme B without the help of the bacteria.
d)
Cattle would no longer be able to use cellulose as a primary source of glucose.
8.
As shown in the diagram, when environmental temperatures drop below freezing, a layer of ice typically forms on the surface of bodies of freshwater such as lakes and rivers.
Which of the following best describes how the structure of ice benefits the organisms that live in the water below?
a)
The water molecules in ice are closer together than those in liquid water, so the ice prevents the passage of air to the water, maintaining a constant gas mixture in the water.
b)
The water molecules in ice are closer together than those in liquid water, so the ice forms a barrier that protects the organisms in the water from the freezing air temperatures.
c)
The water molecules in ice are farther apart than those in liquid water, so the ice floats, maintaining the warmer, denser water at the lake bottom.
d)
The water molecules in ice are farther apart than those in liquid water, so the ice floats, preventing the escape of gases from the liquid water.
9.
Water molecules are polar covalent molecules. There is a partial negative charge near the oxygen atom and partial positive charges near the hydrogen atoms due to the uneven distribution of electrons between the atoms, which results in the formation of hydrogen bonds between water molecules. The polarity of water molecules contributes to many properties of water that are important for biological processes.
Which of the following models best demonstrates the arrangement of hydrogen bonds between adjacent water molecules?
a)
A
b)
B
c)
C
d)
D
10.
Which statement describes how water is pulled up through the xylem to the leaves of the plant?
a)
As water exits the leaf, hydrogen bonding between water molecules pulls more water up from below.
b)
As water exits the leaf, signals are sent to the roots to pump more water up to the leaves through the xylem by adhesion.
c)
Evaporation from the leaf decreases the hydrogen bonds that form between the water molecules in the xylem, which helps the water molecules to be pulled up the xylem.
d)
Evaporation of water from the leaf increases the hydrogen bonds that form between water molecules in the air, providing the energy for transport.
11.
Based on the figure, which statement best describes the observed relationship between atmospheric CO2 enrichment and plant growth under ideal and stressed conditions?
a)
The increase in atmospheric CO2 had no observable effect on plant growth under either ideal or stressed conditions.
b)
The increase in atmospheric CO2 resulted in a greater increase in plant growth under ideal conditions than under stressed conditions.
c)
The increase in atmospheric CO2 resulted in a greater increase in plant growth under stressed conditions than under ideal conditions.
d)
The increase in atmospheric CO2 resulted in an inhibition of plant growth under both ideal and stressed conditions.
12.
Which of the following is the most likely reason for the difference in leaf growth?
a)
The phosphorus-starved plant was unable to synthesize both the required proteins and lipids, limiting growth.
b)
The phosphorus-starved plant was unable to synthesize both the required proteins and carbohydrates, limiting growth.
c)
The phosphorus-starved plant was unable to synthesize both the required nucleic acids and lipids, limiting growth.
d)
The phosphorus-starved plant was unable to synthesize both the required carbohydrates and nucleic acids, limiting growth.
13.
As shown in Figure 1, an amino acid must have which of the following properties in order to be incorporated into a polypeptide?
a)
The ability to remain stable in the presence of water molecules
b)
An R-group that is compatible with the R-group of the last amino acid incorporated
c)
A central carbon atom that reacts with a nitrogen atom to form the peptide bond
d)
The ability to form a covalent bond with both its NH2 group and its COOH group
14.
Which of the following is common feature of the illustrated reactions showing the linking of monomers to form macromolecules?
a)
Two identical monomers are joined by a covalent bond.
b)
Two different monomers are joined by a covalent bond.
c)
Monomers are joined by a covalent bond, and a water molecule is produced.
d)
Monomers are joined by ionic bonds, and a water molecule is produced.
15.
Which of the following describes a key difference among the 20 amino acids that are used to make proteins?
a)
Only some amino acids have an R-group
b)
Only some amino acids have a carboxyl group (COOH)
c)
Some amino acids are hydrophobic.
d)
Some amino acids contain the element phosphorus.
16.
How might this change affect the structure and function of the protein?
a)
The R-group of the new amino acid, valine, has different chemical properties than the R-group of cysteine. This will cause the protein to misfold and not function properly in the cell.
b)
The new amino acid, valine, has replaced cysteine in the new protein. Since the number of amino acids has remained the same, there will be no change in the three-dimensional folding, or function, of the protein.
c)
Since this is a linear section, it does not influence protein folding. Thus, there will be no change in protein structure or function.
d)
Since the new amino acid is bounded on one side by an amino acid with a negatively charged R-group and by an amino acid on the other side with a positively charged R-group, , the charges will balance and the protein will fold as usual.
17.
Which of the following statements is correct about the molecule shown in Figure 1 ?
a)
It is RNA because of the relative direction of the two strands.
b)
It is RNA because of the number of different nucleotides found in the molecule.
c)
It is DNA because of the nature of the hydrogen bonds between guanine and cytosine.
d)
It is DNA because of the nucleotides present.
18.
Which of the following best describes a structural similarity between the two molecules shown in Figure 1 that is relevant to their function?
a)
Both molecules are composed of the same four nucleotides, which allows each molecule to be produced from the same pool of available nucleotides.
b)
Both molecules are composed of the same type of five-carbon sugar, which allows each molecule to act as a building block for the production of polysaccharides.
c)
Both molecules contain nucleotides that form base pairs with other nucleotides, which allows each molecule to act as a template in the synthesis of other nucleic acid molecules.
d)
Both molecules contain nitrogenous bases and phosphate groups, which allows each molecule to be used as a monomer in the synthesis of proteins and lipids.
19.
A certain type of specialized cell contains an unusually large amount of rough endoplasmic reticulum (ER).
Which of the following functions is this cell type most likely specialized to perform?
a)
The production and secretion of steroids
b)
The destruction of toxic materials produced in other cells of the organism
c)
The synthesis of polysaccharides for energy storage
d)
The production and secretion of proteins
20.
Which of the following cellular deficiencies would most likely be related to mutations in mitochondrial proteins?
a)
The cell is unable to synthesize most proteins required for normal cell functions.
b)
The cell is unable to break down toxic materials and would accumulate large volumes of these materials.
c)
The cell is able to synthesize proteins, but the proteins would not fold properly and would not contain the correct molecular tags for export from the cell.
d)
The cell is unable to complete reactions related to electron transport and ATP production.
21.
A scientist is studying the various prokaryotic and eukaryotic species found floating in a sample of water taken from a marine ecosystem.
Which cellular component will be found in the widest range of organisms in the sample?
a)
The chloroplast, since all organisms need a source of energy.
b)
The ribosome, since all organisms need to synthesize proteins.
c)
The mitochondrion, since all organisms need to break down glucose.
d)
The cell wall, since all marine organisms need them for support.
22.
Which of the following conclusions about the radiolabeled amino acid is best supported by the results of the experiment?
a)
It was mostly incorporated into nucleic acids that store the biological information.
b)
It was mostly incorporated into proteins that regulate and manage metabolic reactions.
c)
It was mostly incorporated into lipids that help separate cells from their surrounding environment.
d)
It was mostly incorporated into carbohydrates that form protective structures outside the cells.
23.
Which of the following claims about the effects of the valinomycin treatment is best supported by the data presented in the table?
a)
The valinomycin treatment caused an increase in the activity of the rough endoplasmic reticulum.
b)
The valinomycin treatment caused an increase in the activity of the Golgi complex.
c)
The valinomycin treatment caused a decrease in the activity of the lysosome.
d)
The valinomycin treatment caused a decrease in the activity of the mitochondria.
24.
Which of the following conclusions about increasing the number of folds in the inner mitochondrial membrane is best supported by the results of the experiment?
a)
It increases the efficiency of photosynthesis, which results in faster cell growth.
b)
It increases the surface area available for ATP production, which results in faster cell growth.
c)
It increases the amount of space available for storing cellular wastes, which results in faster cell growth.
d)
It increases the rate of protein transport to the plasma membrane, which results in faster cell growth.
25.
Based on the data, which cell is likely to be most effective in the exchange of materials?
a)
Cell 1
b)
Cell 2
c)
Cell 3
d)
Cell 4
26.
Which of the following provides an accurate calculation of the surface area to volume ratio of an HS red blood cell, as well as a prediction of its effect on the efficient transferring of oxygen compared to a normal red blood cell?
a)
The ratio is 0.45, and the cells are more efficient at transferring oxygen.
b)
The ratio is 1.12, and the cells are less efficient at transferring oxygen.
c)
The ratio is 0.89, and the cells are less efficient at transferring oxygen.
d)
The ratio is 141, and the cells are more efficient at transferring oxygen.
27.
Which of the following best describes how the ratio of the density of stomata (stomata per MM^2) per CO2 concentration (ppm CO2) changes as the CO2 concentration increases?
a)
The ratio decreases from 0.86 to 0.63 , because fewer stomata are needed at higher CO2 concentrations
b)
The ratio decreases from 1.6 to 1.2, becausefewer stomata are needed at higherr CO2 concentrations
c)
The ration increases from 0.63 to 0.86, because more stomata are needed at higher CO2 concetrations
d)
The ratio increases from 1.2 to 1.6, because more stromata are needed at higher CO2 concentrations.
28.
Testosterone is a small steroid hormone that is important in cell signaling. Which of the following describes where testosterone enters a cell and why it is able to cross at that point?
a)
1, testosterone is nonpolar and can diffuse through the membrane.
b)
2, testosterone covalently binds to a surface protein and transports into the cell.
c)
3, testosterone dissolves in water and flows through the channel.
d)
4, testosterone is filtered out of the extracellular fluid and taken into the cell by endocytosis.
29.
Based on the figure, which of the following statements best describes the relationship between regions 1 and 2 of the protein?
a)
Region 1 is hydrophilic because it interacts with the interior of the membrane, whereas region 2 is hydrophobic because it interacts with an aqueous environment.
b)
Region 1 is hydrophilic because it interacts with an aqueous environment, whereas region 2 is hydrophobic because it interacts with the interior of the membrane.
c)
Region 1 is hydrophobic because it interacts with the interior of the membrane, whereas region 2 is hydrophilic because it interacts with an aqueous environment.
d)
Region 1 is hydrophobic because it interacts with an aqueous environment, whereas region 2 is hydrophilic because it interacts with the interior of the membrane.
30.
Which of the following models shows how cholesterol molecules most likely interact with the phospholipid bilayer of a cell’s plasma membrane?
a)
A
b)
B
c)
C
d)
D
31.
The team wants to extend the research project. What should the team of students do next to obtain data that are more conclusive?
a)
Repeat the process with other salt concentrations.
b)
Develop a model to explain why the cells react differently to different salt concentrations.
c)
Repeat the process using red blood cells from other animals.
d)
Develop an experimental procedure that uses a stain that makes the organelles of red blood cells more visible.
32.
What additional procedure would best help determine whether these movements are due to active transport or to passive transport?
a)
Repeat the original experiment, but at three different temperatures. Compare the transport rates among the three temperatures.
b)
Repeat the original experiment, but add a substance known to block movement of molecules across aquaporins. Compare the rates on the two graphs.
c)
Use two additional treatments, one containing only ethyl alcohol and one containing only acetate. Compare the graphs of these two treatments with the original graph.
d)
Use two additional treatments, one containing only ethyl alcohol and one containing only acetate. Include a substance known to block ATP use by the plasma membrane. Compare the graphs of these two treatments to the original graph.
33.
Researchers investigate the transport of a certain protein into cells by endocytosis. In an experiment, the researchers incubate the cells in the presence of the protein and measure the amount of the protein that is absorbed into the cells over a five-minute period.
Based on their observations, what should the researchers do to further clarify how the availability of the protein outside the cells affects the rate of endocytosis of the protein?
a)
Incubate the cells in the absence of the protein.
b)
Incubate the cells in the presence of several different proteins.
c)
Incubate the cells in the presence of several different concentrations of the protein.
d)
Incubate the cells in the presence of the protein for several different lengths of time.
34.
Which of the following best predicts what will happen to the lysosomal enzymes if the proteins that transport H+ ions from the cytosol into the lysosome are damaged?
a)
The lysosomal enzymes will not become active, since there will be no active transport of H+ ions
b)
The lysosomal enzymes will not become active, since H+ ions will diffuse out of the lysosome.
c)
The lysosomal enzymes will become active, since facilitated diffusion will move H+ ions into the lysosome.
d)
The lysosomal enzymes will become active, since passive diffusion will move H+ ions into the lysosome.
35.
Which of the following transport mechanisms will be affected most directly by a temporary shortage of ATP molecules inside the cell?
a)
The movement of water molecules through aquaporins
b)
The diffusion of oxygen molecules across the plasma membrane
c)
The transport of glucose molecules against a concentration gradient
d)
The facilitated diffusion of CA2+ ions into the cell
36.
Based on the model presented in Figure 1, which of the following changes will most likely result from a depletion of available ATP stores inside the cell?
a)
The NA+ concentration outside the cell will increase.
b)
The NA+ concentration inside the cell will increase.
c)
The K+ concentration inside the cell will increase.
d)
The K+ concentration outside the cell will decrease.
37.
A study was conducted to understand the factors controlling the rate at which molecules or ions travel across cell membranes. An artificial membrane was created that was composed of a phospholipid bilayer only. The speed at which various substances crossed this membrane was measured.
Some substances can pass through an actual cell membrane much faster than they passed through the artificial membrane in this study. Which of the following statements best explains this finding?
a)
Actual cell membranes have a much thicker phospholipid bilayer than the artificial membrane does.
b)
Actual cell membranes have a variety of proteins embedded in the membrane that are absent in the artificial membrane.
c)
Hydrophobic substances spend more time between the two layers of phospholipid in the artificial membrane than they do between the layers in an actual membrane.
d)
Hydrophilic substances spend more time attached to the polar region of the phospholipids in the artificial membrane than they do attached to the polar region of the phospholipids in an actual membrane.
38.
A magnesium sulfate solution taken orally can cause a net movement of water into the large intestine, which results from water molecules diffusing through aquaporins embedded in the cells of the intestinal lining.
By which of the following mechanisms do the water molecules most likely move into the large intestine?
a)
By passive transport from an area of low osmolarity to an area of high osmolarity
b)
By passive transport from an area of high osmolarity to an area of low osmolarity
c)
By active transport from an area of low osmolarity to an area of high osmolarity
d)
By active transport from an area of high osmolarity to an area of low osmolarity
39.
Aldosterone (a steroid hormone) is a small, nonpolar, hydrophobic molecule that enters a target cell by moving across the plasma membrane, down a concentration gradient.
Based on the information presented, how does aldosterone most likely enter target cells?
a)
By simple diffusion because aldersterone can enter a cell by moving across the plasma membrane and moving down the concentration gradient.
b)
By facilitated diffusion because aldersterone would need the assistance of a protein channel to move across the plasma membrane.
c)
By active transport because aldersterone would need energy to move across the plasma membrane.
d)
By endocytosis because aldersterone would need to be transported by vesicle across the plasma membrane
40.
Which of the graphs below best represents the predicted change in mass over time of the dialysis bag in the beaker to which albumin was added?
a)
A
b)
B
c)
C
d)
D
41.
Some viral infections can lead to the rupture of the lysosome membrane. Which prediction of the effect of this disruption of cellular compartmentalization is most likely correct?
a)
Enzymes will be released that will specifically target the virus.
b)
Cellular osmotic concentrations will change, preventing viral entry into the cell.
c)
Hydrolytic enzymes will be released, which will cause cell death.
d)
Intracellular digestion of organic materials will increase, which will increase the energy available to the cell for fighting the virus.
42.
Gaucher disease is an inherited disorder in which cells of the body are unable to break down a particular type of lipid, resulting in a buildup of the lipid in some tissues and organs.
Based on the information provided, Gaucher disease results most directly from a defect in the function of which of the following organelles?
a)
The smooth endoplasmic reticulum
b)
The nucleus
c)
The lysosome
d)
The mitochondrion
43.
Researchers have proposed a model of chloroplast evolution. According to the model, chloroplasts evolved from a small prokaryotic organism that was engulfed by an ancestral eukaryote. The engulfed prokaryote then formed an endosymbiotic relationship with the eukaryotic host.
Which of the following observations best supports the model?
a)
Chloroplasts are separated from other subcellular compartments by semipermeable membranes.
b)
Prokaryotic and eukaryotic organisms both acquire nutrients from the surrounding environment.
c)
Eukaryotes evolved after prokaryotes and have more complex structures.
d)
Chloroplasts and some prokaryotes share similar photosynthetic reactions.
44.
Which of the following observations best supports the claim that mitochondria evolved from once-free-living prokaryotic cells by the process of endocytosis?
a)
Mitochondria produce ATP
b)
Mitochondria contain proteins.
c)
Mitochondria exchange substances with the cytosol.
d)
Mitochondria are surrounded by a double membrane.
45.
Which of the following claims about the origin of the euglenid chloroplast is best supported by the three-membrane structure of the envelope?
a)
It originated from the spontaneous assembly of organic molecules into a lipid bilayer inside a free-living prokaryote.
b)
It originated from the fusion of the plasma membranes of two different free-living photosynthetic prokaryotes.
c)
It originated from the incorporation of a photosynthetic prokaryote into a eukaryotic cell by a single endosymbiotic event.
d)
It originated from the incorporation of a photosynthetic prokaryote into a eukaryotic cell by two endosymbiotic events.
46.
Beetroot cells contain a family of dark red pigments called betalains. The selectively permeable nature of the beetroot cells keeps the internal environment of the cell separate from the external environment of the cell. Researchers are interested in determining whether the selective permeability of beetroot cells is due to the cell membrane or if it is due to the cell wall.
Exposure to cellulase is known to damage the structure of the cell wall. An experiment is set up in which beetroot cells are placed in an aqueous solution with cellulase and in one without cellulase.
Which of the following results best refutes the alternative hypothesis that selective permeability is a consequence of the cell wall?
a)
When beetroot cells are placed in a solution with cellulase, the solution turns dark red.
b)
When beetroot cells are placed in a solution with cellulase, the solution remains clear.
c)
When beetroot cells are placed in a solution, it turns dark red with or without cellulase present.
d)
Since plant cells contain cell membranes, not cell walls, the alternate hypothesis cannot be tested.
47.
Which of the following results, one hour after membrane fusion, best supports the alternative hypothesis that the cell membrane is a fluid mosaic?
a)
A
b)
B
c)
C
d)
D
48.
The cell membrane is selectively permeable due to its structure. Thus, the internal environment of the cell is distinct from the external environment of the cell. One biologist hypothesizes that small nonpolar molecules readily pass through the membrane. Another biologist alternatively hypothesizes that these types of molecules require channel and transport proteins that are embedded in the membrane in order to move across the membrane.
Which of the following data would best refute this alternative hypothesis?
a)
Ethanol is found in the cytosol of cells when they are briefly exposed to a ten percent ethanol solution.
b)
Cells become oxygen deficient when membrane protein activity is blocked.
c)
CO2 and N2 movement in and out of cells is unaffected when membrane protein activity is blocked.
d)
Sodium ions cannot move across the cell membrane when membrane protein activity is blocked.
49.
Based on Figure 1, which of the following statements best predicts the effect that a change from a moderately acidic environment (pH near 6) to a basic environment will have on peroxidase activity?
a)
Peroxidase activity will decrease.
b)
Peroxidase activity will increase.
c)
Peroxidase activity will stay the same.
d)
Peroxidase activity will increase at first and then decrease.
50.
Which of the following actions will provide a negative control for the investigation?
a)
Repeating the experiment at 25 C
b)
Repeating the experiment using twice the amount of hydrogen peroxide
c)
Repeating the experiment using twice the amount of peroxidase
d)
Repeating the experiment using heat-denatured peroxidase
51.
One of the researchers proposes using oxygen gas production to measure reaction rates. Which of the following statements best justifies the use of the proposed modification as a way of creating an appropriate control for the investigation?
a)
The experiment can be repeated without hydrogen peroxide, which will help eliminate an uncontrolled variable.
b)
The experiment can be repeated without peroxidase, which will introduce a second independent variable.
c)
The experiment can be repeated without guaiacol, which will reveal the effect of guaiacol on the reaction rates.
d)
The experiment can be repeated without water, which will reveal whether the reaction can occur inside a living cell.
52.
Which of the following statements best helps explain how the lead ion causes inhibition of ALAD?
a)
It changes the shape and charge of the substrate so that it becomes more compatible with ALAD'S active site
b)
It changes the amino acid sequence of the ALAD protein so that the enzyme catalyzes a different reaction.
c)
It changes the three-dimensional structure of the active site so that ALAD is no longer compatible with its substrate.
d)
It changes the enzyme-substrate complex so that the transition state is more stable and the reaction proceeds at a faster rate.
53.
Which of the following statements correctly explains the observed effect of the acetylcholine concentration on the rate of the enzyme-catalyzed reaction?
a)
The active site of AChE is specific for acetylcholine, and only one substrate molecule can occupy the active site at a time.
b)
AChE begins converting product into substrate as the acetylcholine concentration changes from low to high.
c)
The AChe protein becomes denatured as the acetylcholine concentration changes from low to high.
d)
The substrate specificity of AChe changes as the acetylcholine concentration changes from low to high.
54.
A researcher proposes a model to explain how enzyme-substrate interactions determine enzyme specificity. The model is based on the idea that substrate molecules form favorable interactions with the amino acid side chains in an enzyme’s active site.
Based on the model, which of the following statements best explains an enzyme’s specificity for a particular substrate molecule?
a)
A hydrophilic molecule interacts with nonpolar side chains in the enzyme’s active site.
b)
A hydrophobic molecule interacts with polar side chains in the enzyme’s active site.
c)
A molecule with positive charges interacts with positively charged side chains in the enzyme’s active site.
d)
A molecule with negative charges interacts with positively charged side chains in the enzyme’s active site.
55.
A set of five additional test tubes were prepared and used as controls. Which of the following best describes the contents expected to be contained in one of the five control test tubes?
a)
pH 4 buffer solution and hydrogen peroxide only
b)
All five pH buffer solutions combined and hydrogen peroxide only
c)
Water, hydrogen peroxide, and yeast
d)
Water and yeast only
56.
Which test tubes are controls in the experiment?
a)
Test tubes 1 and 2 only
b)
Test tubes 5 and 6 only
c)
Test tubes 1, 3, 5, and 7
d)
Test tubes 2, 4, 6, and 8
57.
Which of the following statements best helps justify the inclusion of group 2 as one of the controls in the experiment?
a)
It will show whether the changes observed in group 1 depend on the metabolic activity of soil bacteria.
b)
It will show whether the changes observed in group 1 depend on the type of plants used in the experiment.
c)
It will show the average growth rate of seedlings that are maintained in a nonsterile environment.
d)
It will show the changes that occur in the roots of seedlings following an infection by soil bacteria.
58.
Which of the following statements best helps justify the inclusion of test tube 5 in the experiment?
a)
It will act as a control for test tube 4 by showing the effect of the presence or absence of the substrate.
b)
It will act as a control for test tube 4 by showing the effect of a change in environmental temperature.
c)
It will act as a control for test tube 6 by showing the effect of the presence or absence of the enzyme.
d)
It will act as a control for test tube 6 by showing the effect of a change in sodium chloride concentration.
59.
Researchers investigated the effect of urea on the three-dimensional structure of a certain enzyme. The researchers dissolved the enzyme in an aqueous buffer solution and added urea to the solution. The enzyme did not appear to have a secondary or tertiary structure. The researchers carefully removed the urea from the solution and determined that the enzyme had the original secondary and tertiary structure again.
Based on the results of the experiment, which of the following statements best predicts the effect of urea on the enzyme’s function?
a)
Function will be disrupted by adding the urea and regained by removing the urea.
b)
Function will be disrupted by adding the urea, but it will not be regained by removing the urea.
c)
Function will be gained by adding the urea and disrupted by removing the urea.
d)
Function will be unaffected by the addition and removal of the urea.
60.
Which of the following best predicts the immediate result of adding more substrate to the reaction mixture at the point indicated by the arrow in Figure 1?
a)
The amount of product will decrease until the reaction rate goes to zero.
b)
The amount of product will decrease until the reaction reaches its equilibrium point or until the enzyme is been used up by the reaction.
c)
The amount of product will increase until the reaction reaches its equilibrium point or until the substrate is used up by the reaction.
d)
The amount of product will increase without stopping because the enzyme will be unchanged by the reaction.
61.
Based on the data, scientists claim that the reproductive behavior of European flycatchers is influenced by the availability of energy sources. Which of the following statements best justifies this claim?
a)
Young European flycatchers hatch from eggs when caterpillar biomass is available for the young birds to consume and convert into energy for growth.
b)
European flycatcher hatchlings begin to need energy to leave the nest only after the caterpillars have turned into pupae.
c)
Female European flycatchers require energy to lay eggs, so they lay their eggs when the caterpillar biomass is maximal.
d)
The energy requirements for hatching European flycatchers and caterpillars are proportional to each other.
62.
A researcher claims that the incorporation of carbon dioxide into organic molecules during photosynthesis does not violate the second law of thermodynamics.
Which of the following statements best helps justify the researcher’s claim?
a)
Organisms contain enzymes that lower the activation energies of specific chemical reactions.
b)
An ecosystem is formed by the interaction of a community of organisms with their surrounding environment.
c)
Photosynthetic organisms use the organic molecules produced during photosynthesis for growth and repair.
d)
The total system that includes photosynthetic organisms and the Sun becomes less ordered over time.
63.
Which of the following statements provides reasoning that supports the claim that brown fatty tissue keeps an animal warm?
a)
The uncoupling protein in this tissue increases the production of ATP and causes more body heat to be produced to warm the animal.
b)
The uncoupling protein in this tissue reduces the proton gradient across the membrane and thus produces heat to warm the animal without ATP production
c)
The uncoupling protein in this tissue causes an increase in the proton gradient, which causes more ATP to be produced that helps to warm the animal.
d)
The uncoupling protein in this tissue reduces the production of ATP and creates an increase in the proton gradient that allows more heat energy to be produced to warm the animal.
64.
Which of the following graphs best represents data from the experiment that will support the researcher’s claim?
a)
A
b)
B
c)
C
d)
D
65.
Which of the following types of evidence will best support the researcher’s claim?
a)
Evidence that some of the earliest eukaryotes used oxygen to produce ATP by cellular respiration
b)
Evidence that the earliest plants produced oxygen as a by-product of photosynthesis
c)
Evidence that some of the earliest organisms carried out photosynthesis without producing oxygen
d)
Evidence that the cyanobacteria produced oxygen as a by-product of photosynthesis
66.
Which of the following statements best clarifies how the data support the researcher’s claim?
a)
The thylakoid membrane is more permeable to carbon dioxide than to polar molecules.
b)
ATP synthase activity depends on a proton gradient across the thylakoid membrane.
c)
Some enzymes embedded in the thylakoid membrane catalyze the hydrolysis of ATP
d)
Carbon fixation in the Calvin-Benson cycle takes place in the stroma of chloroplasts.
67.
A researcher claims that genetic variation provides organisms with the ability to survive and reproduce in different environments. To support the claim, the researcher makes the following observation: bacteria that contain plasmids (small DNA molecules) are resistant to a wider range of antibiotics than are bacteria that contain no plasmids.
Which of the following statements best establishes a connection between the observation and the researcher’s claim?
a)
Some antibiotics inhibit the synthesis of bacterial cell walls.
b)
Some antibiotics inhibit protein synthesis in bacteria cells.
c)
Some plasmids cannot exist in a bacterial cell with certain other plasmids.
d)
Some plasmids contain antibiotic resistance genes.
68.
Phycobiliproteins are a complex of accessory pigments and proteins found in cyanobacteria but not in green algae. A researcher claims that the phycobiliprotein pigments in cyanobacteria allow the cyanobacteria to survive in certain aquatic niches better than green algae can.
Which of the following statements best justifies the researcher’s claim?
a)
The additional pigments allow the cyanobacteria to store light energy so that it can be used at night to continue photosynthesis.
b)
The additional pigments block light and prevent it from reaching photosynthetic organisms at greater depths, so no photosynthetic organisms can live below the surface waters containing cyanobacteria.
c)
The additional pigments require energy and cellular resources to produce, so they can be used as an energy source during times of insufficient light.
d)
The additional pigments absorb light at wavelengths that green algae cannot absorb; this may allow cyanobacteria to capture more light energy for photosynthesis than green algae can in certain areas.
69.
A researcher claims that budding yeast are able to survive in different environments because they produce enzymes that allow them to use different molecules as sources of matter and energy.
Which of the following statements best helps justify the researcher’s claim by providing a relevant example?
a)
Yeast cells produce protein kinases, which are enzymes that catalyze the transfer of phosphate groups from ATP to protein substrates.
b)
Yeast cells produce DNA polymerases, which are enzymes that catalyze the conversion of free nucleotides into strands of DNA
c)
Yeast cells produce invertase, which is an enzyme that catalyzes the conversion of the disaccharide sucrose into glucose and fructose.
d)
Yeast cells produce catalase, which is an enzyme that catalyzes the conversion of hydrogen peroxide into water and oxygen gas.
70.
An antigen can induce an immune response in a host organism. Antigens are targeted by antibodies that are produced by the organism’s immune system in response to contact with the antigen. Antibodies are specific to antigens. Many different cell types are involved in immune responses.
Which of the following best explains the role of cell-to-cell communication during a response to an invasion of antigens?
a)
Chemicals that are secreted from antigen-presenting cells then activate helper T cells.
b)
A macrophage cell engulfs a pathogen in the blood.
c)
Antigens attaching to receptors on memory B cells stimulate the memory B cells to become plasma cells.
d)
Antigen-presenting cells engulf antigens at the first exposure.
71.
Adjacent plant cells have narrow channels called plasmodesmata that pass through the cell walls of the connected cells and allow a cytoplasmic connection between the cells.
Which of the following statements best explains a primary function of plasmodesmata?
a)
They allow the movement of molecules from one cell to another, enabling communication between cells.
b)
They prevent the cell membrane from pulling away from the cell wall during periods of drought.
c)
They eliminate the need to produce signaling molecules and eliminate the need for cells to have receptors for signaling molecules.
d)
They increase the surface area available for attachment of ribosomes and thus increase protein synthesis.
72.
A hydrophilic peptide hormone is produced in the anterior pituitary gland located at the base of the brain. The hormone targets specific cells in many parts of the body.
Which of the following best explains a possible mechanism that would enable the hormone to efficiently reach all of the target cells in the body?
a)
The hormone interacts with the nerves at the base of the brain and directs signals to the target cells through the nervous system.
b)
The hormone diffuses into target cells adjacent to the anterior pituitary gland, where the hormone is degraded.
c)
The hormone is released into the bloodstream where it can be transported to all cells with the correct receptors.
d)
The hormone moves through cytoplasmic connections between cells until it has reached all cells with the correct intracellular binding sites.
73.
Which of the following describes a critical role of cAMP during the transduction stage of a G protein signal transduction pathway?
a)
cAMP carries the signal to the nucleus of the cell and results in new sequences of nucleotides being added to the cell’s DNA
b)
cAMP binds the extracellular signal molecule and carries it to the intracellular target specified by the signal.
c)
cAMP modifies a specific monomer so that it can be added to an elongating structural macromolecule.
d)
cAMP results in the activation of an enzyme that amplifies the signal by acting on many substrate molecules.
74.
Which of the following best describes the component that metformin represents in a signal transduction pathway that regulates glucose production in the liver?
a)
It is a secondary messenger that amplifies a signal through a cascade reaction.
b)
It is a ligand that activates the signal transduction pathway of the activation of AMPK
c)
It is an allosteric regulator that binds to a crucial section of the DNA that makes the enzymes needed for glucose uptake.
d)
It is a competitive inhibitor that binds to glucose and prevents it from entering the cell.
75.
Which of the following steps in a signaling pathway typically occurs first once a chemical messenger reaches a target cell?
a)
Specific genes are activated.
b)
A second messenger molecule is produced.
c)
A ligand binds to a receptor.
d)
Specific proteins are synthesized.
76.
During a fight-or-flight response, epinephrine is released into the body’s circulatory system and transported throughout the body. Some cells exhibit a response to the epinephrine while other cells do not.
Which of the following justifies the claim that differences in components of cell signaling pathways explain the different responses to epinephrine?
a)
Cell signaling depends on the ability to detect a signal molecule. Not all cells have receptors for epinephrine. Only cells with such receptors are capable of responding.
b)
Cell signaling depends on the transduction of a received signal by the nervous system. Not all cells are close enough to a synapse to receive the signal and respond.
c)
Cell signaling depends on the signal being able to diffuse through the cell membrane. Epinephrine is incapable of diffusing through some plasma membranes because of the membrane’s phospholipid composition.
d)
Cell signaling requires reception, transduction, and response. All cells can receive epinephrine, all cells respond with a pathway, but only select cells have the proper coding in their DNA to respond.
77.
Signal transduction may result in changes in gene expression and cell function, which may alter phenotype in an embryo. An example is the expression of the SRY gene, which triggers the male sexual development pathway in mammals. This gene is found on the Y chromosome.
Which statement provides the evidence to justify the claim that signal transduction may result in an altered phenotype?
a)
If the SRY gene is absent or nonfunctional, the embryo will exhibit male sexual development.
b)
If the SRY gene is absent or nonfunctional, the embryo will exhibit female sexual development.
c)
An embryo with a male sex chromosome will always exhibit male sexual development.
d)
An embryo with two male sex chromosomes will always exhibit male sexual development.
78.
Which of the following statements best justifies the claim that changes in the expression of ced-9 in C. elegans can affect regulation of apoptosis in the cell?
a)
An experiment showed that a mutation in the ced-9 gene led to excessive cell death in C. elegans.
b)
An experiment showed that the ced-9 gene normally produces a protein that promotes excessive cell death in C. elegans.
c)
A mutation in ced-3 will cause ced-9 to be incorrectly transcribed.
d)
Apoptosis is dependent on a signal from the ced-9 gene in C. elegans.
79.
The insulin receptor is a transmembrane protein that plays a role in the regulation of glucose homeostasis. The receptor’s extracellular domain binds specifically to the peptide hormone insulin. The receptor’s intracellular domain interacts with cellular factors. The binding of insulin to the receptor stimulates a signal transduction pathway that results in the subcellular translocation of GLUT4 , a glucose transport protein that is stored in vesicles inside the cell. A simplified model of the insulin receptor–signaling pathway is shown in Figure 1.
Which of the following statements best predicts the effect of a loss of function of the insulin receptor’s intracellular domain?
a)
The stimulation of the signal transduction pathway will increase.
b)
The storage of GLUT4 in vesicles inside the cell will increase.
c)
The number of GLUT4 molecules in the plasma membrane will increase.
d)
The concentration of glucose inside the cell will increase.
80.
The beta-2 adrenergic receptor is a membrane-bound protein that regulates several cellular processes, including the synthesis and breakdown of glycogen. The receptor binds specifically to the hormone epinephrine. The binding of epinephrine to the beta-2 adrenergic receptor triggers a signal transduction cascade that controls glycogen synthesis and breakdown in the cell. A simplified model of the signal transduction cascade is represented in Figure 1.
Which of the following outcomes will most likely result from the inactivation of the beta-2 adrenergic receptor?
a)
The cellular concentration of cyclic AMP will increase
b)
The enzymatic activity of protein kinase A will increase.
c)
The activation of glycogen phosphorylase will increase.
d)
The rate of glycogen synthesis in the cell will increase.
81.
Which of the following changes in the FGFR signaling pathway is most likely to result in uncontrolled cell proliferation?
a)
The irreversible association of FGFR proteins
b)
The loss of the FGFR protein kinase function
c)
A decrease in the intracellular concentration of ATP
d)
A decrease in the extracellular concentrations of fibroblast growth factors
82.
A researcher found a mutation that resulted in the PFK enzyme being unable to bind ATP to the allosteric site. Which of the following best predicts the effect of the mutation?
a)
The activity of the enzyme will not be affected because the active site is not involved in substrate binding at the allosteric site.
b)
Negative feedback regulation does not occur, so the enzyme will be active when glycolysis is not needed.
c)
Positive feedback does not occur, and the activity of the enzyme will decrease when glycolysis is needed.
d)
The activity of the enzyme will fluctuate independent of the ATP concentration
83.
Which of the following best predicts what will happen to the blood glucose level if the person has another meal at 5 p.m.?
a)
Immediately after the meal, the blood glucose level will decrease because of the increase in glucagon levels.
b)
Immediately after the meal, the blood glucose level will increase, and then insulin will be secreted to counter the increase.
c)
Several hours after the meal, the blood glucose level will increase sharply because of an increase in the amount of glucagon secreted.
d)
The blood glucose level will not change after the 5 p.m. meal because the person has already consumed two meals and the blood glucose level has been adjusted to a steady-state level.
84.
Warfarin is a drug used to treat certain blood clots. Warfarin blocks the formation of the active form of vitamin K-dependent clotting factors. Based on the model, which of the following best predicts the effects of warfarin on a patient?
a)
Fibrinogen will form fibrin, but the clot will not form because Factor XIII will not be synthesized.
b)
The intrinsic pathway will take over because the clotting factors are part of that pathway.
c)
Thrombin will be converted to prothrombin because Factor will reverse the reaction.
d)
Factor X will not be activated, which will prevent thrombin from forming.
85.
Based on Table 1, what percent of the life cycle of yeast cells is spent in DNA replication?
a)
5 percent
b)
10 percent
c)
25 percent
d)
50 percent
86.
Based on the sample means, which of the following conclusions about the cells in the growing root tips of Zea mays seedlings is best supported by the results of the experiment?
a)
The cells of the root tips grow to larger sizes when the seedlings are planted in compact sand than when the seedlings are planted in loose sand.
b)
The average rate of mitotic cell division is greater for the root tips growing in loose sand than for the root tips growing in compact sand.
c)
The average cell cycle time is greater for the root tips growing in compact sand than for the root tips growing in loose sand.
d)
More cells are produced per unit of time in the root tips growing in compact sand than in the root tips growing in loose sand.
87.
Based on Figure 1, which of the following statements correctly links a stage of the cell cycle with the event occurring at that stage?
a)
Stage I represents the G2 phase of the cell cycle
b)
Synthesis of sufficient DNA for two daughter cells occurs in stage II
c)
Stage III includes mitosis.
d)
The replication of genetic material occurs in stage IV
88.
Which of the following statements is consistent with the data in Figure 1?
a)
The cells have a haploid chromosome number of 3.
b)
The cells have a diploid chromosome number of 6.
c)
There is a change from 3 to 6 picograms of DNA because DNA is replicated before each round of cell division.
d)
There is a change from 6 to 3 picograms of DNA after each cell division because the chromosomes lengthen following cell division.
89.
Which of the following most accurately describes an observation and an effect of the viral infection indicated by the data in Table 1?
a)
Normal cells spend 98 percent of their time cycling in and out of interphase. The virus reduces this to 5 percent of the time.
b)
Twenty percent of the virus-infected cells are in interphase. These cells are no longer part of the cell cycle.
c)
Forty percent of the virus-infected cells are in interphase. These cells are preparing for replication of genetic material.
d)
Seventy-five percent of the virus-infected cells are found in mitosis. The virus stimulates frequent cell division.
90.
Based on the data, the percent of the mitotic cells that were in metaphase is closest to which of the following?
a)
5%
b)
11%
c)
18%
d)
66%
91.
Which of the following best predicts the effect of a mutation that causes EGFR to be active in the absence of a growth factor?
a)
Increased apoptosis will lead to abnormal growth of the tissue.
b)
Increased cell division will lead to the formation of a tumor.
c)
Cells will exit the cell cycle, entering a non-dividing G0 Phase
d)
Fewer cells will be in any of the stages of mitosis.
92.
Which of the following will most likely result from a loss of p53 function?
a)
Rapid cell growth without cell division
b)
Immediate activation of apoptosis pathways
c)
Uncontrolled cell proliferation
d)
Increased expression of p53
93.
Which statement best predicts why a cell’s progression through the cell cycle might be halted at the G1/S checkpoint?
a)
Spindle fibers have not correctly attached to chromosomes.
b)
There are not enough nucleotides available to construct new DNA
c)
Damage occurred to DNA when it was being copied in G1
d)
Proteins necessary for M phase of the cell cycle have not been produced.
94.
Which of the following best explains how the sweet pea plants in the parental generation produce F1 offspring with 14 chromosomes?
a)
Meiosis I and II lead to the formation of cells with 14 chromosomes. When two cells combine during fertilization, extra chromosomes are randomly broken down, leading to offspring with 14 chromosomes.
b)
Meiosis I and II lead to the formation of cells with 14 chromosomes. When two cells combine during fertilization, extra chromosomes with recessive traits are broken down, leading to offspring with 14 chromosomes.
c)
Meiosis I and II lead to the formation of cells with 7 chromosomes. During meiosis I homologous chromosomes separate. During meiosis II sister chromatids separate. Two cells combine during fertilization to produce offspring with 14 chromosomes
d)
Meiosis I and II lead to the formation of cells with 7 chromosomes. During meiosis I sister chromatids separate. During meiosis II homologous chromosomes separate. Two cells combine during fertilization to produce offspring with 14 chromosomes.
95.
Which of the following questions would be most useful to researchers trying to determine the role of meiosis in the F2 phenotypic frequencies?
a)
What is the molecular mechanism underlying the dominance of erect petals and long pollen?
b)
Which phenotypes give pea plants the highest level of fitness: erect or hooded petals and long or round pollen?
c)
How do the phases of meiosis differ between sweet pea plants and other organisms?
d)
What is the recombination frequency between the genes for petal shape and pollen shape?
96.
How many degrees of freedom should be used when looking up the critical value for a chi-square analysis of the ratios of phenotypes observed among the F2 offspring versus the expected phenotypic ratio assuming independent assortment?
a)
2
b)
3
c)
4
d)
5
97.
For sexually reproducing diploid parent cells, which of the following statements best explains the production of haploid cells that occurs in meiosis but not in mitosis?
a)
Separation of chromatids occurs once, and there is one round of cell division in meiosis.
b)
Separation of chromatids occurs twice, and there are two rounds of cell division in mitosis.
c)
Separation of chromatids occurs once, and there are two rounds of cell division in meiosis.
d)
Separation of chromatids occurs twice, and there is one round of cell division in mitosis
98.
Which of the following best explains a distinction between metaphase I and metaphase II?
a)
The nuclear membrane breaks down during metaphase I but not during metaphase II
b)
Chromosomes align at the equator of the cell during metaphase II but not during metaphase I
c)
The meiotic spindle is needed during metaphase I but not during metaphase II
d)
Homologous pairs of chromosomes are aligned during metaphase I , but individual chromosomes are aligned during metaphase II
99.
A compound that prevents the separation of the homologous chromosomes in anaphase I is being studied. Which of the following questions can be best answered during this study?
a)
Will the cells produced at the end of meiosis still be genetically identical to each other in the presence of this compound?
b)
Will the long-term development of the individual be affected by this meiotic error?
c)
When do the centrosomes start to move apart during meiosis I as compared to meiosis II?
d)
Is there a pattern to the movement of homologous chromosomes in the presence of this compound?
100.
Based on Figure 1, which of the following questions could best be addressed?
a)
Does synapsis of homologous chromosomes in the parent cell contribute to an increase in genetic diversity in the daughter cells?
b)
Do sister chromatids separate and form diploid daughter cells?
c)
Do chromatids from nonhomologous chromosomes rearrange to produce identical daughter cells?
d)
Does synapsis of nonhomologous chromosomes produce daughter cells that are identical to the parent cell?
101.
Which of the following is closest to the calculated chi-square (x^2) value for the data presented in Table 1?
a)
8.35
b)
72.01
c)
98.00
d)
2,546.00
102.
Based on the data in Figure 1, which of the following is the best prediction of the mode of inheritance of red eyes in Japanese koi?
a)
The allele for red eyes is inherited in an autosomal dominant pattern.
b)
The allele for red eyes is inherited in an autosomal recessive pattern.
c)
The allele for red eyes is inherited in an x-linked recessive pattern.
d)
The allele for red eyes is inherited in an x-linked dominant pattern.
103.
Using a significance level of p=0.05 , which of the following statements best completes a chi-square goodness-of-fit test for a model of independent assortment?
a)
The calculated chi-square value is 0.66, and the critical value is 0.05. The null hypothesis can be rejected.
b)
The calculated chi-square value is 0.66, and the critical value is 3.84. The null hypothesis cannot be rejected.
c)
The calculated chi-square value is 3.91, and the critical value is 5.99. The null hypothesis can be rejected.
d)
The calculated chi-square value is 3.91, and the critical value is 7.82. The null hypothesis cannot be rejected.
104.
For this condition, which of the following modes of inheritance is most consistent with the observations?
a)
Autosomal dominant
b)
Autosomal recessive
c)
X-linked dominant
d)
X-linked recessive
105.
Which of the following tables best shows the expected values in the F2 generation for a chi-square goodness-of-fit test for a model of independent assortment?
a)
A
b)
B
c)
C
d)
D
106.
Glycolysis is a metabolic pathway that converts glucose into pyruvate and is observed in each of the three domains. The hexokinase family of enzymes is required during glycolysis to phosphorylate six-carbon sugars. Researchers designed a general hexokinase inhibitor that is effective in the neurons of rats.
Which of the following best predicts the effect of adding this inhibitor to a culture of plant cells?
a)
Plant cells will be unaffected by the inhibitor as they do not perform glycolysis.
b)
Plant cells will be unable to perform glycolysis due to the inhibitor and will die.
c)
Plant cells will be unable to perform photosynthesis due to the inhibitor and will die.
d)
Plant cells will still be able to perform glycolysis since plant hexokinase is not structurally similar to animal hexokinase.
107.
The students plan to use a significance level of p=0.01. Which of the following is the most appropriate critical value for the students to use in their chi-square goodness-of-fit test?
Responses
a)
7.82
b)
11.34
c)
13.28
d)
326.7
108.
The mean map distance between gene R and gene L is closest to which of the following?
a)
0.28 map units
b)
28 map units
c)
0.14 map units
d)
14 map units
109.
The researchers calculated a chi-square value of 29.25. If there are three degrees of freedom and the significance level is p=0.05 , which of the following statements best completes the chi-square test?
a)
The critical value is 0.05, and the null hypothesis cannot be rejected because the calculated chi-square value is greater than the critical value.
b)
The critical value is 0.05, and the null hypothesis can be rejected because the calculated chi-square value is greater than the critical value.
c)
The critical value is 7.82, and the null hypothesis cannot be rejected because the calculated chi-square value is greater than the critical value.
d)
The critical value is 7.82, and the null hypothesis can be rejected because the calculated chi-square value is greater than the critical value.
110.
Which of the follow indicates the mean number per cross of F2 plants producing medium-red grain and correctly explains the distribution of the phenotypes?
a)
The mean number of medium-red phenotypes per cross is 20.8. The distribution of phenotypes suggests that grain color is under environmental control.
b)
The mean number of medium-red phenotypes per cross is 20.8. The distribution of phenotypes suggests that multiple genes are involved in grain color determination.
c)
The mean number of medium-red phenotypes per cross is 104. The distribution of phenotypes suggests that grain color is under environmental control.
d)
The mean number of medium-red phenotypes per cross is 104. The distribution of phenotypes suggests that multiple genes are involved in grain color determination.
111.
The mean number of fruit flies per student that are homozygous recessive for both genes is closest to which of the following?
a)
89.75
b)
29.0
c)
22.75
d)
18.5
112.
Himalayan rabbits are a breed of rabbits with highly variable fur color. If genetically similar rabbits are raised in environments that have different temperature conditions, the rabbits can have different color patterns.
Which of the following statements best explains how the fur color can be different in Himalayan rabbits raised under different temperature conditions?
a)
The genotype does not contribute to coat color in Himalayan rabbits.
b)
The phenotype determines the genotype of coat color in Himalayan rabbits.
c)
Different environments cause specific mutations in the genes controlling pigment production.
d)
The environment determines how the genotype is expressed.
113.
The tadpoles of Mexican spadefoot toads are known to exhibit phenotypic plasticity depending on food availability. Tadpole mouthparts can vary significantly, prompting researchers to categorize them as either omnivore-morph or carnivore-morph. Carnivore-morph tadpoles are larger and have mouthparts that are better suited for predation. Remarkably, carnivore-morph tadpoles can change into omnivore-morph tadpoles when the food supply changes.
Which of the following best describes an advantage of the phenotypic plasticity displayed by the tadpoles?
a)
It allows the tadpoles to change their genome in response to environmental pressures.
b)
It enables the tadpoles to develop into a distinct species of toads.
c)
It gives the tadpoles increased versatility with respect to diet.
d)
It allows the tadpoles to delay metamorphosis until there is maximal food available for the adults.
114.
When a mustard plant seedling is transferred to an environment with higher levels of carbon dioxide, the new leaves have a lower stomata-to-surface-area ratio than do the seedling’s original leaves.
Which of the following best explains how the leaves from the same plant can have different stomatal densities when exposed to an elevated carbon dioxide level?
a)
Increased photosynthesis leads to larger leaves that need more stomata for photosynthesis, leading to an increase in stomatal density.
b)
Leaf growth is promoted through increased photosynthesis, but the genetically regulated rate of stomatal production is not altered, leading to a decrease in stomatal density.
c)
Leaf growth is inhibited by decreased photosynthesis, and the genetically regulated rate of stomatal production remains the same, leading to an increase in stomatal density.
d)
Leaf growth is inhibited by decreased photosynthesis, and the genetically regulated rate of stomatal production remains the same, leading to a decrease in stomatal density.
115.
Which of the following best predicts the effect of the chromosomal segregation error shown in Figure 1?
a)
All of the resulting gametes will have an extra chromosome.
b)
All of the resulting gametes will be missing a chromosome.
c)
Half of the resulting gametes will have an extra chromosome and the other half will be missing a chromosome.
d)
Half of the resulting gametes will have the correct number of chromosomes, and the other half will have an incorrect number of chromosomes.
116.
If the woman and a man with normal clotting function have children, what is the probability of their children exhibiting hemophilia A?
a)
50 percent for daughters, 0 percent for sons
b)
50 percent for sons, 0 percent for daughters
c)
50 percent for all children
d)
0 percent for all children
117.
Which of the following is most likely the immediate cause of the first appearance of Huntington’s disease in a person?
a)
A point mutation occurs in the HTT gene
b)
The first appearance of the CAG repeat occurs in the HTT gene
c)
An allele with more than 39 CAG repeats was inherited by the affected person.
d)
The person inherited two alleles that each contained 20 CAG repeats
118.
Which of the following claims about the TYR, TRP2, and TRP1 mammalian genes is most likely to be accurate?
a)
The TYR, TRP2, and TRP1 genes are located next to each other on a single chromosome and are organized into an operon.
b)
The TYR, TRP2, and TRP1 genes may be located on different chromosomes but are activated by the same transcription factor.
c)
The TYR, TRP2, and TRP1 genes are identical genes since they are activated by the same transcription factor.
d)
The TYR, TRP2, and TRP1 genes may be located on different chromosomes but with identical operator sequences.
119.
Which of the following claims best explains why keratinocytes do not produce melanin?
a)
Keratinocytes do not contain the TYR, TRP2, and TRP1 genes.
b)
Keratinocytes do not contain the Mc1R gene
c)
Keratinocytes do not express the MITF gene
d)
Keratinocytes do not express the POMC gene
120.
Which of the following pieces of evidence would best support the researchers’ claim above?
a)
When researchers applied a drug that activates adenylyl cyclase to the mutant mice’s ears, the level of melanin increased.
b)
When researchers viewed sections of mutant mouse ears under the microscope, they found melanocyte numbers comparable to nonmutant mice.
c)
When researchers exposed the mutant mice to UV radiation the amount of POMC mRNA in keratinocytes did not change.
d)
When researchers exposed the mutant mice to UV radiation , the level of melanin production did not change.
121.
Based on the information provided in Figure 1 and Figure 2, which of the following best explains the effects of a mutation in the promoter of the TYR gene that prevents it from being transcribed?
a)
DNA damaged due to UV radiation will be strongly inhibited, resulting in a positive selection pressure.
b)
DNA damaged due to UV radiation will be strongly inhibited, resulting in a negative selection pressure.
c)
Skin pigmentation will not be able to change, resulting in a positive selection pressure.
d)
Skin pigmentation will not be able to change, resulting in a negative selection pressure.
122.
Which of the following best explains a process occurring between point 1 and point 2 in Figure 3 ?
a)
a-MSH is produced
b)
The TYR gene is transcribed
c)
Polypeptides are removed from a protein
d)
A poly-A tail is added to RNA
123.
Which of the following best predicts the phenotype of an individual who is homozygous for this TYR mutation?
a)
The mutation will cause a single amino acid change in the TYR protein, which will not be enough to disrupt its function. Therefore, those with this mutation will produce melanin in the hair, skin, and eyes and tan in response to UV radiation
b)
The mutation will cause a single amino acid change in the TYR protein, leading to a nonfunctional TYR protein. Therefore, those with this mutation will lack melanin in the hair, skin, and eyes and will not tan in response to UV radiation
c)
The mutation will change all subsequent amino acids in the TYR protein, leading to nonfunctional TYR protein. Since the TRP1 and TRP2 genes were not affected, the TRP1 and TRP2 proteins will fill the role of the TYR protein. Therefore, those with this mutation will produce melanin in the hair, skin, and eyes in response to UV radiation
d)
The mutation will change all subsequent amino acids in the TYR protein, leading to nonfunctional TYR protein. Individuals with this mutation will lack melanin in their hair, skin, and eyes and will not tan in response to UV radiation
124.
Which of the following statements best explains the experimental results observed in Figure 1 ?
a)
E. coli in both lanes B and C have been successfully transformed and contain additional genetic information.
b)
E. coli in lane B have been successfully transformed and contain additional genetic information.
c)
E. coli in lane C have been successfully transformed and contain additional genetic information.
d)
Which E. coli have been transformed cannot be determined from this gel.
125.
Which of the following best explains how the pattern of DNA arrangement in chromosomes could be used, in most cases, to determine if an organism was a prokaryote or a eukaryote?
a)
A
b)
B
c)
C
d)
D
126.
Which of the following best explains how the results should be interpreted?
a)
The individual does not have an increased risk of developing cancer because one dominant allele is insufficient to cause the disease.
b)
The individual has an increased risk of developing colon cancer
c)
Because the person’s DNA has the mutation, other family members must have cancer.
d)
Results cannot be interpreted until testing determines if additional mutated alleles are present.
127.
Given the results shown in Figure 1, which of the following correctly describes a relationship between the two species?
a)
Species B is the ancestor of species A because it has fewer bands.
b)
Species A is more complex than species B because it has more bands.
c)
Species B has more short fragments of DNA than species A does
d)
Species A has more short fragments of DNA than species B does
128.
Which of the following best helps explain how the process represented in Figure 1 produces DNA molecules that are hybrids of the original and the newly synthesized strands?
a)
Each template strand is broken down into nucleotides, which are then used to synthesize both strands of a new DNA molecule
b)
Each template strand is broken into multiple fragments, which are randomly assembled into two different molecules
c)
Each newly synthesized strand is associated with another newly synthesized strand to form a new molecule
d)
Each newly synthesized strand remains associated with its template strand to form two copies of the original DNA molecule
129.
Which of the following graphs best predicts the data collected during the experiment?
a)
A
b)
B
c)
C
d)
D
130.
Which of the following best predicts what will happen when a normal cell is exposed to a retrovirus?
a)
The reverse transcriptase will cut the host DNA into fragments, destroying the host cell.
b)
The reverse transcriptase will insert the viral RNA into the host’s genome so it can be transcribed and translated.
c)
The reverse transcriptase will produce DNA from the viral RNA , which can be incorporated into the host’s genome and then transcribed and translated.
d)
The reverse transcriptase will force the host ribosomes to translate the viral RNA prior to polypeptide assembly.
131.
Which of the following statements best explains what is shown in Figure 1 ?
a)
UV exposure triggers DNA replication, which results in rapid cell proliferation.
b)
Naturally occurring dimers are removed by the UV photons, causing misshapen DNA , which results in replication errors.
c)
The hydrogen bonds between base pairs absorb the UV photons, separating the two DNA strands, which results in rapid DNA replication
d)
UV photons cause dimers to form, leading to misshapen DNA , which results in replication and transcription errors.
132.
Which of the following evidence best supports a claim that tryptophan functions as a corepressor?
a)
Normal expression of trpR causes the trp operon to be transcribed regardless of tryptophan levels.
b)
When the operator sequence is mutated, the trp operon is not transcribed.
c)
The trp gene codes for a repressor protein that has a DNA binding domain.
d)
When trpR is mutated, the trp operon is transcribed regardless of tryptophan levels.
133.
A cell needs to metabolize the substrate illustrated in Figure 1 for a vital cellular function. Which of the following best explains the long-term effect on the cell of splicing that yields only enzyme c mRNA?
a)
The cell will die because it is unable to metabolize the substrate without enzyme A, which is structurally specific for the substrate shown.
b)
The cell will remain healthy because all three of the above enzymes can metabolize the substrate, as they are from the same gene.
c)
The cell will remain healthy because the enzyme c mRNA will undergo alternative splicing again until it transformed into enzyme A mRNA
d)
The cell will remain healthy because enzyme-substrate interactions are nonspecific and enzyme C will eventually metabolize the substrate.
134.
Which of the following statements best explains the role of Enzyme 1 in the DNA replication process?
a)
Enzyme 1 is a DNA ligase that joins together the DNA fragments at a replication fork to form continuous strands.
b)
Enzyme 1 is a DNA primase that catalyzes the synthesis of RNA primers on the lagging strand of a replication fork.
c)
Enzyme 1 is a DNA polymerase that synthesizes new polymerase that synthesizes new DNA by using the leading and lagging strands of a replication fork as templates.
d)
Enzyme 1 is a topoisomerase that relieves tension in the overwound DNA in front of a replication fork.
135.
Which of the following best supports the claim that binding of miRNA-delta to the miRNA binding site inhibits translation of gene Q mRNA?
a)
When the promoter for gene Q is altered, transcription is inhibited.
b)
Translation of Q mRNA is inhibited regardless of whether the miRNA binding site sequence is altered.
c)
Translation of Q mRNA is inhibited in the absence of miRNA-delta
d)
When the miRNA binding site sequence is altered, translation of Q mRNA occurs in the presence of miRNA-delta
136.
Which of the following statements provides the best explanation of the processes illustrated in Figure 1 ?
a)
Introns are removed from the pre-rRNA , and the mature rRNA molecules are joined and then translated to produce the protein portion of the ribosome.
b)
Introns are removed from the pre-rRNA , and each mature rRNA molecule is translated to produce the proteins that make up the ribosomal subunits.
c)
Sections of the pre-rRNA are removed, and the mature rRNA molecules are available to combine with proteins to form the ribosomal subunits.
d)
Sections of the pre-rRNA are removed, and the mature rRNA molecules are available to bring different amino acids to the ribosome.
137.
A woman develops Huntington’s disease. Her father had the disorder. Her mother did not, and there is no history of the disorder in the mother’s family. Which of the following best explains how the woman inherited Huntington’s disease?
a)
She inherited an allele with fewer than 40 CAG repeats in the HTT gene because her mother did not have Huntington’s disease.
b)
She inherited an allele with more than 40 CAG repeats in the HTT gene from her father.
c)
Her mother produced eggs that all have more than 40 repeats in the HTT gene
d)
Her mother produced eggs that all have fewer than 40 CAG repeats in the HTT gene
138.
Which of the following best explains how this model illustrates DNA replication of both strands as a replication fork moves?
a)
I and IV are synthesized continuously in the 5' to 3' direction
b)
II and III are synthesized in segments in the 3' to 5' direction
c)
I is synthesized continuously in the 5' to 3' direction, and III is synthesized in segments in the 5' to 3' direction
d)
II is synthesized in segments after DNA polymerase is released from synthesizing strand IV
139.
Which claim is most consistent with the information provided by the diagram and current scientific understanding of gene regulation and expression?
a)
Reversible changes in the DNA sequence may influence how a gene is expressed in a cell.
b)
Some sequences of DNA can interact with regulatory proteins that control transcription.
c)
This is an inducible operon controlled by several regulatory factors.
d)
The transcription factor may produce mutations in the binding site at the promoter sequence inhibiting the synthesis of the protein.
140.
Based on the information in Figure 1, which type of mutation explains the nature of the change in DNA that resulted in cystic fibrosis in the affected individual?
a)
Substitution, because the amino acid tryptophan is replaced with glycine.
b)
Insertion, because an extra guanine is present, which changes the reading frame.
c)
Deletion, because a thymine is missing, which changes the reading frame.
d)
Duplication, because the amino acid leucine occurs twice, which changes the reading frame.
141.
Nucleotide base pairing in DNA is universal across organisms. Each pair (T-A; C-G) consists of a purine and a pyrimidine. Which of the following best explains how the base pairs form?
a)
Ionic bonds join two double-ringed structures in each pair.
b)
Hydrogen bonds join two single-ringed structures in each pair.
c)
Hydrogen bonds join a double-ringed structure to a single-ringed structure in each pair.
d)
Covalent bonds join a double-ringed structure to a single-ringed structure in each pair.
142.
Researchers have undertaken a long-term study of populations of rock pocket mice, Chaetodipus intermedius, in Arizona and New Mexico. Rock pocket mouse fur is either dark or light in color. Most of the populations studied live in areas with light-colored granite rocks; however, some areas are dominated by dark-colored rocks from ancient lava flows. Researchers collected mice from six sites in Arizona and recorded their coat colors. Figure 1 shows the study sites, the rock colors, and the distribution of coat colors.
Which of the following best describes the processes occurring between the mouse populations and their environments?
a)
Natural selection favors the mice with the dark coat color, causing the mice in all of the populations to be better adapted.
b)
Natural selection favors the mice with the light coat color, causing the mice in all of the populations to be better adapted.
c)
Dark color is selected for in mice from the West, Mid, and East populations.
d)
Light color is selected for in mice from the West, Mid, and East populations.
143.
Owls (primary predators of rock pocket mice) are nocturnal visual predators that are able to distinguish effectively between dark and light colors in low-light conditions.
Which of the following best explains the relationship between coat color and predation rate in the rock pocket mouse population on the lava flow rocks with respect to the different coat color phenotypes?
a)
A dark coat color provides camouflage to mice on the lava flow rocks; therefore, mice with dark coats have a lower predation rate in that habitat.
b)
At night, predators have reduced vision, so there is no relationship between coat color and predation rate on rock pocket mice.
c)
A dark coat color reflects less light and therefore mice with dark coats have a lower predation rate.
d)
A light coat color reflects more light and therefore mice with light coats have a lower predation rate.
144.
Based on the data in Table 1, which of the following best describes the relationship between the MC1R gene and coat color in the Carrizozo, New Mexico, rock pocket mouse population?
a)
The MIRC D allele is responsible for dark coat color in the Carrizozo population and likely spread from the Arizona population through migration.
b)
The MIRC D allele is not responsible for dark coat color in the Carrizozo population, so the dark coat color is likely a result of convergent evolution.
c)
The MIRC D allele is absent from the Carrizozo population, so all the mice in this population must have coats that are light in color.
d)
The MIRC D allele is absent from the Carrizozo population because of different environmental pressures in the Carrizozo population.
145.
The researchers built an enclosure to prevent migration into and out of the O’Neill rock pocket mouse population for a period of two years.
Which of the following best predicts the effect of the enclosure on the O’Neill population?
a)
The O’Neill population will rapidly evolve into a separate species.
b)
The O’Neill population will become less diverse due to the bottleneck effect.
c)
The frequency of the MC1RD allele will decline due to natural selection.
d)
One of the alleles for the MC1RD gene will become fixed due to genetic drift.
146.
Which of the following is closest to the frequency of the MC1RD allele in the Tule Mountain population?
a)
0.03
b)
0.06
c)
0.94
d)
0.97
147.
The researchers determined that the East lava flow population is not in Hardy-Weinberg equilibrium.
Which of the following best explains why the population is not in Hardy-Weinberg equilibrium?
a)
The presence of heterozygotes for the MC1R gene in the East lava flow population indicates that mating is occurring randomly between mice with different coat colors.
b)
The selective pressures on the East lava flow population are not strong enough to maintain Hardy-Weinberg equilibrium.
c)
The East lava flow population does not experience migration, which is a required condition for Hardy-Weinberg equilibrium.
d)
The presence of the MC1R d alleles in the East lava flow population is an indication of gene flow from mice populations living on light granite rocks.
148.
Geologic events such as mountain building can directly affect biodiversity. The Sino‑Himalayan fern, Lepisorus clathratus is widely distributed on the Qinghai‑Tibetan plateau.
If geologic events lead to a series of new mountain ranges that divide the plateau into several discrete valleys, which of the following best describes how the L. clathratus population would be affected?
a)
Geographic isolation will create separate gene pools, leading to speciation over time.
b)
Gene flow will be reduced by sexual selection and polyploidy.
c)
Chance events will cause allele frequencies to fluctuate unpredictably from one generation to the next.
d)
Ferns reproduce asexually, so there will be no impact on the gene pool of the species.
149.
Based on the phylogenetic relationships shown in Figure 1, which of the following best explains the similarities exhibited by whales, bony fishes, and cartilaginous fishes?
a)
Convergent evolution, because these organisms do not share a recent common ancestor.
b)
Adaptive radiation, because all three groups evolved from a unique, shared common ancestor from the cartilaginous fishes group.
c)
Mutation, because the shared traits can be traced back to a shared recent common ancestor.
d)
Founder effect, because all three groups formerly existed together as one population that then was disrupted, causing speciation.
150.
Scientists claim that some of the populations in Marion County are at an increased risk of decline or extinction. Based on the data in table 1, which of the following best provides evidence to support this claim?
a)
The Marion County populations have a higher rate of mutation than the Jasper County populations, as evidenced by the higher degrees of relatedness.
b)
The Marion County populations are less stable because they are smaller than the Jasper County populations.
c)
The M2 population has a higher degree of relatedness than the M1 population, meaning that it has more genetic diversity.
d)
The M4 and M5 populations have the lowest genetic diversity of all populations.
151.
Assuming that the population is in Hardy‑Weinberg equilibrium, which of the following is the expected frequency of individuals with the genotype MN?
a)
0.148
b)
0.295
c)
0.640
d)
0.672
152.
Based on the information provided in the figure, which of the following best describes how membrane-bound organelles provided unique evolutionary advantages to the last eukaryotic common ancestor?
a)
Cells with nuclear membranes were better able to protect their genetic material against damage.
b)
Cells with flagella were better able to find food and escape predators.
c)
Cells with ribosomes were better able to produce proteins needed for a variety of metabolic functions.
d)
Cells with mitochondria were able to utilize metabolic energy more efficiently.
153.
Some plant species flower in response to increasing daily temperatures in the spring. Many of these species rely on pollinators that migrate based on changes in day length and the position of the Sun. The current global warming trend is placing new selective pressures on the species involved in these relationships.
Which of the following best explains the impact of these new selective pressures on the organisms involved?
a)
If the environment for the plant species becomes too warm, the pollinators will no longer migrate to that area in the spring, continuing on to a more northern environment instead.
b)
The warmer temperatures will lead to a drier environment, so the plants will no longer produce enough nectar to attract the pollinators.
c)
The plant species will flower earlier in the spring in response to rising temperatures before the arrival of the pollinators, so seeds will not be produced.
d)
Migrating pollinators will start migrating later in the year, switching from spring-flowering plants to summer-flowering plants.
154.
A scientist wishes to provide experimental evidence to support the model shown in Figure 1 by demonstrating the ability to synthesize an RNA molecule. Which of the following is an alternative hypothesis that can be tested to support the RNA World Hypothesis?
a)
A protein template that matches proteins found on the primitive Earth added to a mixture of deoxyribonucleotides will produce double-stranded DNA molecules
b)
Double strands of DNA placed in a harsh environment will unwind and form RNA molecules for long term information storage.
c)
A pool of amino acids can spontaneously form into single‑stranded RNA , which would then code for proteins.
d)
A mixture of ribonucleotides such as adenine and uracil will spontaneously form single-stranded chains of RNA
155.
Which of the specimens indicated in the table is the oldest?
a)
Specimen 1
b)
Specimen 2
c)
Specimen 3
d)
Specimen 4
156.
Which of the following student claims is best supported by the data provided?
a)
Mushrooms and potatoes are most closely related, since the node they share gave rise to all of the other organisms.
b)
Cattle are equally related to pigs and sheep, because the phylogeny places cattle between pigs and sheep.
c)
Yeast and mushrooms are the most closely related, because they are both fungi.
d)
Cattle and sheep are separated by only one node, and they are separated from the other organisms by more than one node.
157.
The island was surveyed again in 2015, and scientists determined that the giant kangaroo rats originally in population A are now to be considered as a new species.
Which of the following best explains the mechanism that caused this speciation event in the giant kangaroo rats of population A?
a)
The animals in population A were exposed to different predators and had to modify their fur color to be better camouflaged.
b)
The animals in population A were reproductively isolated from those in populations B, C, and D.
c)
The animals in population A accumulated fewer genetic mutations, adapting to their microclimate.
d)
The animals in population A mate at different times of year, causing their gametes to be incompatible with those from animals in populations B, C, and D.
158.
Mollusk fossils were excavated and collected from a coastal cliff. Scientists studying the fossils observed patterns of changing shell shape in the mollusks. The scientists identified a period of stability or stasis, followed by rapid change, and then stasis again with regard to shell shape.
Which of the following statements best predicts the result of a comparison between the fossils found before and after the period of rapid change?
Responses
a)
The same species will be found in both static periods, but they will have different shell shapes.
b)
The same species will be found in both static periods, but the species in the second static period will have smaller shells due to the stress of undergoing rapid change.
c)
Most of the species found in the first static period will be absent in the second static period.
d)
Most of the species found in the second static period will resemble each other more than the species found in the first static period.
159.
Because cheetahs, Acinonyx jubatus, experienced a bottleneck event about ten thousand years ago, living cheetahs exhibit very little genetic variation compared to other living species of large cats.
Which of the following principles best justifies a claim that cheetahs, compared to other large cats, have a relatively low resilience to environmental perturbations?
a)
A captive population of cheetahs kept in a confined area will have a greater risk of contracting and passing on a virus.
b)
When a population is reduced, new niches become available in the environment, which can trigger adaptive radiation.
c)
Populations with little genetic diversity are less likely to contain individuals that can withstand different selective pressures.
d)
Populations with low genetic diversity are more likely to contain individuals that can withstand different selective pressures.
160.
Some researchers claim that the decrease in plant species richness of this woodlot is unrelated to human activities over the last forty years.
Which of the following would be an appropriate alternative hypothesis?
a)
Interspecific competition caused the extinction of species 4 and 5.
b)
The woodlot environment is arid and species 1 and 2 are well-adapted to conserve water.
c)
The woodlot is shaded, with little direct sunlight, and species 3, 4, and 5 are shade-intolerant canopy trees.
d)
During the last few decades, tall buildings have been built around the woodlot, and species 3, 4, and 5 are shade‑intolerant plants
161.
In a particular region, a species of lizard lives in the lowlands. Even though there are numerous mountains in the region, the climate on the mountains is too cold for the lizards to survive. Scientists are concerned that the lowlands will become much warmer by the end of the twenty-first century and will become unsuitable for this lowland lizard species.
Which of the following best predicts the impact on the lizard species if there is a gradual increase in the average temperatures found in both the lowlands and mountains in this region?
a)
Some lizards will migrate to new habitats in the mountains and become isolated, leading to allopatric speciation.
b)
The species will undergo artificial selection, as the genes will adapt to warmer temperatures.
c)
The species will experience a genetic bottleneck, and sympatric speciation will result in the development of several new species.
d)
The lizards will hybridize with a different lizard species that is adapted to a warmer environment, leading to increased genetic variation in the species.
162.
Which of the following best describes the expected distribution of proboscis size of the moths at the end of the five‑year study?
a)
A
b)
B
c)
C
d)
D
163.
Which of the following best describes what occurred during the periods indicated by the arrows?
a)
Natural selection acted on variation that was present in both populations A and B, and the lack of gene flow eventually led to the formation of two new species.
b)
Population B was separated for a longer time from the original population than population A was, and population B evolved into a more distinct new species than population A did.
c)
Gene flow between populations A and B maintained sufficient variation in both gene pools to facilitate the development of two distinct species.
d)
In response to different environments, populations A and B experienced different mutation rates, leading to the emergence of two different gene pools and, over time, new species A and B.
164.
The peppered moth, Biston betularia was generally white in color with black speckles. Over time a more solid black moth became the more common variety. Which of the following best explains the relationship between wing pigmentation and the coloration of a moth’s surroundings?
a)
The frequencies of the different phenotypes in the moth population changed randomly due to genetic drift.
b)
If the surroundings of the peppered moth became darker, those backgrounds conferred a selective advantage to a black variety, as described by natural selection.
c)
There was a gene flow of the black variety, spreading it throughout the moth’s normal range.
d)
The black variety was a nineteenth century mutation, dominant to the peppered variety. The allele for the peppered trait, being recessive, decreased in frequency over time
165.
Of the following, which is the best next step for the researchers to best determine the long-term effectiveness of these insecticides with regards to the development of resistance?
a)
Continue treating the three insect populations with the same insecticides and determine whether their efficiencies decline significantly after several generations.
b)
Add an additional treatment group to the experiment to measure the effectiveness of another insecticide (Insecticide #3) over several generations.
c)
Set up a new experiment in which these insects are sprayed with two different insecticides to see if they are more effective than Insecticides #1 and #2.
d)
Spray these insecticides on a different species of insect (whose genotypes are also known) to determine its effectiveness on insects that are not pests.
166.
Which of the following sets of data provides evidence that best supports common ancestry for organisms in all three domains?
a)
There are autotrophic and heterotrophic organisms found in Bacteria, Archaea, and Eukarya.
b)
There is a progression of pathways in organisms found in Bacteria, Archaea, and Eukarya.
c)
Organisms in Bacteria, Archaea, and Eukarya each have adenine, thymine, guanine, and cytosine bases forming their DNA
d)
There is a progression of cellular organization in organisms found in Bacteria, Archaea, and Eukarya.
167.
The heterotroph hypothesis of the origin of life states that basic organic building blocks formed from inorganic molecules under the primitive conditions present early in Earth’s development. These building blocks combined to form polymers, such as crude proteins. Dr. Sidney Fox wished to add to the heterotroph hypothesis of the origin of life by synthesizing simple proteins from a mixture of amino acids.
Which statement below best states an alternative hypothesis Fox could have used to frame his research?
a)
Formation of crude proteins occurs by chance and occurs regardless of atmospheric O2 levels or available free energy.
b)
Given aerobic conditions and large amounts of lightning, amino acids will spontaneously form crude proteins.
c)
Formation of simple proteins on primitive Earth only occurs spontaneously if the required building blocks were transported to Earth by a celestial event or a meteorite.
d)
In the presence of available energy and the absence of a significant quantity of atmospheric O2 simple proteins will form spontaneously from a mixture of amino acids.
168.
Iridium is an element that is rare on Earth but commonly found in meteorites. A scientist believes that the first organic molecules may have come to Earth on meteorites 3.6 billion years ago. Which of these would be an appropriate null hypothesis to test related to whether meteorites hit the Earth 3.6 billion years ago?
a)
If sediment layers that are 3.6 billion years old are tested, they will contain relatively high iridium levels, because that is when many meteorites crashed into the Earth.
b)
There is no difference in iridium levels in sediments that were deposited on Earth 3.6 billion years old, compared to recent sediments.
c)
If a sediment layer that is 3.6 billion years old is tested, it will contain organic material.
d)
If recently fallen meteorites and meteoroids collected in space are tested, they will not contain organic molecules.
169.
Which of the following would most affect the allelic frequencies of the populations on Isabela and Butuan?
a)
Migration of individuals between the Isabela and Butuan populations
b)
Immigration of individuals from Metro Manila into the two populations
c)
Random mating within each population
d)
Increased population sizes over time in the Isabela population, but no change in the Butuan population
170.
Which of the following best explains the trend shown in Figure 1?
a)
The distance the horses ran became shorter between 1880 and 1940.
b)
All of the selective breeding programs ended in 1940.
c)
After 1940, natural selection prevented any additional speed increases.
d)
By 1940, most genetic variation for speed had been lost from the gene pool.
171.
There are two species of elephant seals: northern elephant seals, Mirounga angustirostris, found off the western coast of North America from Baja California to the Gulf of Alaska, and southern elephant seals, M. leonina, found in the southern oceans. Hunting in the nineteenth century has been blamed for a drastic reduction in the northern elephant seal population. Even though the population has rebounded following restrictions on seal hunting, genetic variation is greatly reduced in the northern species compared to that in the southern species.
Which of the following conditions of Hardy-Weinberg equilibrium was most likely not met in the northern elephant seal population following overhunting?
a)
Absence of selection
b)
No new mutations
c)
Random mating
d)
Large population size
172.
If a fire caused the surface of the ground in the habitat of the species to become darker in color, which of the following claims about the impact on the allele frequencies in this population is most reasonable?
a)
The frequency of homozygous recessive individuals will increase because light-colored fur absorbs less heat.
b)
The frequency of the B allele will increase because light-colored individuals will be more visible to predators.
c)
The frequency of the b allele will increase because there will be more heterozygous individuals.
d)
The frequency of both alleles will increase because the population will enter a period of rapid growth.
173.
A group of researchers noticed that using a particular drug to treat cancer in mice would reduce the size of the tumor, but some of the tumor cells appeared to be resistant to the drug since some of these cells would increase in number over time. The researchers wish to increase the reliability of their experimental observations before investigating new claims that chemotherapy-resistant tumors are an example of continuing evolution.
Of the following, which is the best next step the researchers might take to increase the reliability of their evidence?
a)
Increasing the dose of chemotherapy being administered to the mice
b)
Increasing the number of trials and the number of mice in each treatment group
c)
Plotting the tumor volume data as a graph rather than as a table
d)
Isolating resistant tumor cells and looking for novel mutations in proto-oncogenes
174.
Which of the following best illustrates the change in the frequencies of the A and a alleles from generation 1 to generation 2 and to future generations, assuming Hardy-Weinberg equilibrium is present after generation 1 ?
a)
A
b)
B
c)
C
d)
D
175.
A scientist is studying the impact of mutagens on genetic variation in mice. In an experiment, the scientist creates two groups of twenty highly inbred mice. Because the mice are highly inbred, they are essentially identical to one another. One group is given food with an added substance that is known to be a mutagen. The second group is fed the same food without the mutagen. After several generations, both groups of mice are given a new type of food that is harder to digest than the previous food. After rearing five additional generations of the mice on this new food, the two groups are assessed for how efficiently this new food is digested.
Which of the following is the most reasonable prediction about the results of the experiment?
a)
Neither group of mice will show any change in the ability to digest the food because thousands of years are required to develop such a change.
b)
Both groups of mice will show an increase in the ability to digest the new food, because they experienced the same selective pressures.
c)
The group of mice fed the mutagen will show a greater ability to digest the food, because the higher genetic variation within the group makes it more likely that some individuals will have a combination of genes better adapted to the new food.
d)
The group fed the mutagen will show a decrease in the ability to digest the new food, because the mutagen prevented natural selection from acting on them.
176.
Which of the following best explains the divergence in morphology in the birds?
a)
The original habitat contained mutagens, leading to the rise of new species as a result of accumulated mutations.
b)
The original habitat had many available unoccupied ecological niches that were colonized by populations of the original species.
c)
The original habitat contained many predators, and the species diversified in order to avoid extinction.
d)
The original habitat was tropical, which increased the rate of mutation and led to rapid diversification
177.
A group of researchers claim that chance events play an important role in the evolution of populations. To test their claim, they monitored 12 populations of E. coli for 10,000 generations under the same environmental conditions. They found that although all 12 populations were exposed to the same environmental pressures, each population had differentiated from one another genetically after 10,000 generations.
Which of the following statements includes a reasonable refinement that researchers could use in repeating the experiment?
a)
Start each population with genetically identical bacterial cells from a single culture to make sure that the initial genetic variation in all of the populations was exactly the same.
b)
Start each population with a different species of bacteria to determine whether the same environment has an effect on genetic differentiation.
c)
Start each population with bacterial cells that have different genotypes to make sure there is enough genetic variation for selection to occur.
d)
Start each population with bacteria that differ from one another by a single mutation to ensure that the initial genetic variation in all populations is known.
178.
Some scientists propose that due to human activity and climate change, a sixth mass extinction has already begun. Select the best alternate hypothesis to support this claim.
a)
Current temperature changes will correlate with temperature changes during previous extinctions.
b)
Observed modern extinction rates will resemble the rates found early in previous extinctions.
c)
The number of species present on Earth will equal the number of species on Earth before the last extinction.
d)
The number of species present on Earth will equal the number of species on Earth after the last extinction.
179.
A scientist maintains a large population of the fruit fly Drosophila affinis in the laboratory. After 20 generations of allowing this population of about 1000 flies to mate randomly, 10 females and 10 males were isolated from the rest of the population. Both the larger population and the isolated population were maintained under identical conditions and allowed to mate randomly for another 20 generations. After the 20 generations, DNA sequencing was used to determine the genetic composition of each population.
Which of the following predicts the expected outcome of the experiment?
a)
The two populations will show significant genetic differences because the founder effect will result in significant losses in diversity in the smaller population.
b)
The two populations will show significant genetic differences because there will be much higher rates of mutation in the smaller population.
c)
The two populations will not show any differences because they were reared under identical conditions.
d)
The two populations will not show any differences because they originated from the same gene pool
180.
Which of the following represents an alternate hypothesis tested by this experiment with regard to the population sizes of Henslow's sparrows?
a)
There will be no difference in the populations observed in the controlled fire sites and the rest of counties 5 and 6.
b)
Population numbers will continue to decline even in the controlled fire sites because human activities always lead to extinction.
c)
Controlled fires in counties 6 and 8 will have no effect on the sparrow populations.
d)
Controlled fires in counties 4 and 5 will lead to an increase in the sparrow population.
181.
Which of the following best predicts why the recombinant bacteria will fail to produce the eukaryotic protein?
a)
Introns must be removed from eukaryotic DNA before the gene is inserted into the plasmid.
b)
Bacterial ribosomes cannot recognize eukaryotic mRNA and will not translate the codon sequence.
c)
Restriction enzymes in the cytoplasm of the bacteria degrade linear DNA
d)
Bacteria and eukaryotes use different mRNA codons for the same amino acids during translation.
182.
Which of the following best predicts why humans and mice have identical telomeric repeat sequences?
a)
Humans and mice have the same number of genes.
b)
Humans and mice have the same number of chromosomes.
c)
Humans and mice share a recent common ancestor that had the 5' TTAGGG3' repeat sequence in its telomeres.
d)
Mice utilized the 5' TTAGGG3' telomeric repeat sequence first, but the sequence independently evolved in humans as well.
183.
Which of the following would most likely represent the types of individuals found in one of the species resulting from shape becoming a prezygotic isolating mechanism in the initial population represented in Figure 1 ?
a)
A
b)
B
c)
C
d)
D
184.
Based on information in Figure 1, which of the following is closest to the annual growth rate of the wolf population in Yellowstone National Park from 1996 to 2004 ?
a)
4 wolves per year
b)
17 wolves per year
c)
87 wolves per year
d)
135 wolves per year
185.
Based on the data in the figure, a student claimed that since 2007, the carrying capacity of wolves in Yellowstone National Park has been 100 wolves, and the maximum annual per capita growth rate of gray wolves is 0.6 wolves per wolf per year.
Which of the following is closest to the calculated wolf population size in 2017 based on the student’s claim?
a)
100
b)
103
c)
113
d)
173
186.
Identify the independent variable for the experimental results shown in Figure 2.
a)
The presence of wolves
b)
The proportion of time
c)
Coyote behavior
d)
The study area
187.
Which of the following best describes the change in coyote behavior in the presence of wolves?
a)
A
b)
B
c)
C
d)
D
188.
Which of the following is the most likely cause of the change in mean aspen height from 1998 to 2010?
a)
The reintroduction of wolves led to a decrease in the population of elk, allowing aspen trees to grow taller.
b)
The reintroduction of wolves led to a decrease in the population of small mammals, allowing aspen trees to grow taller.
c)
The reintroduction of wolves led to an increase in the number of carcasses that provided fertilizer for young aspen trees.
d)
The reintroduction of wolves led to an increase in the number of carcasses, so coyotes no longer ate young aspen trees.
189.
Meerkats live together in groups to help raise and protect their offspring. Meerkat pups are most vulnerable when they are away from their burrow foraging for food. Adult meerkats exhibit sentinel behavior, standing upright and making alarm calls to warn other members in the group that predators are nearby.
In a study of meerkat behaviors, scientists observed meerkat foraging groups and recorded the presence or absence of pups along with the frequency of adult sentinel behavior. The scientists determined that sentinel behavior increased when pups were present in the foraging group.
Which of the following correctly identifies the dependent and independent variables in the described study?
a)
The frequency of sentinel behavior is the independent variable, and the presence of pups is the dependent variable.
b)
The presence of pups is the independent variable, and the frequency of sentinel behavior is the dependent variable.
c)
The number of predators is the independent variable, and the presence of pups is the dependent variable.
d)
The distance from the burrow is the independent variable, and the number of predators is the dependent variable.
190.
Based on the information in Figure 1, which of the following best predicts a short-term effect of removing secondary consumer X from the community?
a)
A
b)
B
c)
C
d)
D
191.
How do the data in Figure 1 support the alternative hypothesis that increased use of Bt corn reduces the impact of corn farming on the natural environment?
a)
The increased use of Bt corn will result in rapid mutation in corn borers.
b)
The toxin in Bt corn kills only the corn pests, leaving other insects unharmed.
c)
Other insect species will replace corn borers and require additional applications of insecticides.
d)
Since Bt corn is not natural like non-Bt corn, it will not interact with the rest of the environment.
192.
Which of the following correctly identifies the dependent variable and the independent variable for the experiment?
a)
The dependent variable is the time interval the plants were exposed to the hornworms and the independent variable is the percent change in the amount of nicotine.
b)
The dependent variable is the absence or presence of hornworms, and the independent variable is the initial amount of nicotine.
c)
The dependent variable is the initial amount of nicotine, and the independent variable is the final amount of nicotine.
d)
The dependent variable is the percent change in the amount of nicotine, and the independent variable is the time interval the plants were exposed to the hornworms.
193.
Of the following, which explains why the zooplankton also dipped during the same year and then seemed to cycle over the next three years?
a)
The zooplankton rely on the same nutrients for energy harvesting as the phytoplankton, so their population was also unable to acquire the necessary energy to maintain their population level. After that major dip there were enough nutrients for both categories of plankton.
b)
Zooplankton are more temperature-sensitive than the phytoplankton, so the annual seasonal changes will affect their population sizes in a cyclical fashion. There was a sudden, extreme temperature change in the first dip that also affected the phytoplankton.
c)
A migration of whales was blown off course by a storm one year and ate most of the phytoplankton and zooplankton. In the following years the whales returned to their normal migration route.
d)
The reduction in the phytoplankton population meant that the zooplankton’s energy source was drastically reduced, leading to the decrease in the zooplankton population size. After the dip, the phytoplankton provided a steady energy source, and the zooplankton population fluctuated around its carrying capacity.
194.
Bison in Yellowstone National Park have a food-limited carrying capacity that determines how their population grows. If the population grows too large, some bison will either starve or migrate to search for more food. The park is able to support a maximum population of 4,500 bison. Park conservation officials must watch the population and prevent the bison from overpopulating, since they would migrate to nearby farms, causing agricultural damage and creating hazards to drivers. The bison begin to migrate when the population reaches 4,000 because of competition for food.
If the current population size of bison is 3,652 and the maximum growth rate of the population is 0.28, calculate the population size after one year and determine whether the park will need to take measures to control the population.
a)
The population will be 3,845 after a year. The bison will not pose a problem until the following year, and no conservation action will need to take place.
b)
The population will be 4,675 after a year. Some bison will need to be removed to prevent migration, since they will surpass the resource availability.
c)
The population will be 1,023 after a year, since the growth rate is too low. Conservation efforts will need to focus on increasing the bison population.
d)
The population will be 4,500 after a year. The bison cannot exceed the carrying capacity, so they will stop reproducing. Some bison will need to be removed.
195.
What do the data in Figure 1 suggest about a null hypothesis that the East China Sea ecosystem is unaffected by climactic events?
a)
The null hypothesis is rejected since there are statistical effects of EAWM and PDO on surface sea temperature and copepod abundance.
b)
The null hypothesis is rejected because the El Niño Southern Oscillation has a statistical impact on the abundance of copepods in the ECS
c)
The null hypothesis is rejected because the EAMW and PDO do not have statistical effects on the abundance of copepods and phytoplankton in the ESC
d)
The null hypothesis is rejected because the El Niño Southern Oscillation does not have a statistical impact on the abundance of copepods in the ECS
196.
Which of the following best describes a statistical relationship indicated in Figure 1 ?
a)
Yellow bedstraw plants grow significantly more in the presence of both soil bacteria and AM fungi (treatment 4) than in the presence of soil bacteria alone (treatment 2).
b)
Yellow bedstraw plants, in the presence of AM fungi (treatment 3), grow significantly more if soil bacteria (treatment 4) are also present.
c)
Yellow bedstraw plants grow significantly more when soil bacteria (treatment 2) are present compared to when there are no soil bacteria (treatment 1).
d)
Yellow bedstraw plants grown in soil without bacteria and AM fungi (treatment 1) grow significantly more than when only AM fungi is present in the soil (treatment 3).
197.
Based on the data in Figure 1, which of the following statements is most accurate about the species diversity of the four different environments that the students analyzed?
a)
The light, moist environment is the most ideal environment for plants.
b)
The most diverse environment is the dark, dry environment because plants are best able to protect themselves from drying out during the summer months.
c)
Based on the data, there is no statistical difference between the species diversity of plants in the light, moist environment and in the dark, moist environment.
d)
Based on the data, there is no statistical difference between the species diversity of plants in light, dry and dark, dry environments.
198.
In a study of energy flow, the following data were collected:
Each human requires 55 grams of protein per day.An acre of soybeans produces 200,000 grams of protein per year.A cow grazing on one acre of land produces 19,000 grams of protein per year.
Based on these data, an acre of land would support:
10 humans per year on a diet of soy, or0.9 human per year on a diet of beef.
Which of the following statements best explains these relationships in terms of energy transfer?
a)
Humans are better adapted to make efficient use of soy protein than beef protein, so they can extract more energy from a gram of soy protein than from a gram of beef protein.
b)
A cow can harvest energy only at a certain rate, so adding another cow to the acre of land would double the number of humans supported by the acre.
c)
Preparing meat for human consumption takes more energy per gram of protein than preparing soy for consumption.
d)
Only 10% of the energy on each level of the trophic pyramid is available for use by the next level. The rest is lost as heat or used for growth and repair.
199.
The marine iguana, Amblyrhynchus cristatus, is endemic to the Galápagos Islands and is especially vulnerable to El Niño events. These iguanas feed on red and green algae. During an El Niño climate event, surface waters and their currents in the central and eastern Pacific Ocean become significantly warmer than usual. Also during El Niño years, land masses experience increased rainfall.
A researcher suggests that El Niño conditions cause a significant decrease in the size of the Galápagos marine iguana population. Which of the following would best support this alternative hypothesis?
a)
Increased rainfall on land leads to increased nutrient runoff into the ocean and increased food resources for marina iguanas.
b)
Warm surface water contains fewer nutrients needed by red and green algae than cooler surface waters does.
c)
Warm surface water shortens the incubation time of marine iguana embryos.
d)
Cool surface water decreases the metabolic rate of marine iguanas, so they need more food to compensate for the lowered metabolic rate.
200.
Some researchers link changes in the distribution of these species to warming of the oceans due to climate change. Which of the following pieces of data best supports this alternative hypothesis?
a)
Decreased acidity of ocean water in the more southern latitudes caused a migration of these species northward.
b)
These species evolved new adaptations over time, allowing them to survive in warmer ocean environments.
c)
The prey of these species require colder waters to survive, and owing to warming in the oceans, they are moving farther north, to higher latitudes, where the water is colder.
d)
Diseases devastated the prey of these species, forcing them to move northward as insufficient food was available in their original range.
201.
Which of the following best predicts the effects of an increase in killer whale predation on sea otters on the Adak Island ecosystem?
a)
Both the sea urchin population and the kelp population will increase, leading to greater total biomass and diversity in the Adak Island ecosystem.
b)
Both the sea urchin population and the kelp population will decrease, leading to reduced total biomass and diversity in the Adak Island ecosystem.
c)
The sea urchin population will increase and the kelp population will decrease, leading to greater total biomass and diversity in the Adak Island ecosystem.
d)
The sea urchin population will increase and the kelp population will decrease, leading to reduced total biomass and diversity in the Adak Island ecosystem.
202.
Which of the following best explains the data in Table 1?
a)
All forty colonies are genetically identical. Differences in stress responses are due to experimental error.
b)
Asexual reproduction allows stressed colonies to divide rapidly and compete for limited resources with other colonies.
c)
Mild nutritional stress does not trigger a change in reproductive strategy among yeast cultures.
d)
Yeast respond to nutritional stress with sexual reproduction, producing new genetic combinations, or dormancy.
203.
A group of researchers suggest that the concentration of available phosphate in this particular section of the British river does not have a significant impact on which plant species grow. Alternatively, another group of researchers hypothesize that levels of available phosphate do affect which plant species grow at this location. Which of the following observations would best support this alternative hypothesis?
a)
Reforestation efforts in Britain near this section of the river have caused changes in the plant community structure.
b)
Increased fertilizer use near this section of the river has led to increased runoff of phosphates into the river.
c)
Spiked water-milfoil adapted to lower phosphorous conditions has been observed to outcompete fennel-leaved pondweed in this section of the river.
d)
Measured levels of SRP in this section of the river have remained constant over a period of time.
204.
Which of the following best supports the alternate hypothesis that zebra mussels display characteristics of an invasive species?
a)
Lacking natural predators and able to outcompete native species of mussels and other freshwater species for food, zebra mussels have experienced exponential population growth and rapid expansion into new habitats.
b)
Since their arrival, zebra mussels have undergone rapid adaptive radiation, producing new species in many different habitats.
c)
Throughout their current range, zebra mussels coexist with native mussel species, whose populations have been unaffected by the arrival of zebra mussels.
d)
Zebra mussels can crossbreed with native mussels, producing hybrids that are better adapted in the range shown in Figure 1.
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