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WorksheetsPractice AP Biology Exam (from Course Description)
Total questions: 40
Worksheet time: 10hrs 0mins
By discharging electric sparks into a laboratory chamber atmosphere that consisted of water vapor, hydrogen gas, methane, and ammonia, Stanley Miller obtained data that showed that a number of organic molecules, including many amino acids, could be synthesized. Miller was attempting to model early Earth conditions as understood in the 1950s. The results of Miller's experiments best support which of the following hypotheses?
The molecules essential to life today did not exist at the time Earth was first formed.
The molecules essential to life today could not have been carried to the primordial Earth by a comet or a meteorite.
The molecules essential to life today could have formed under early Earth conditions.
The molecules essential to life today were initially self-replicating proteins that were synthesized approximately four billion years ago.
Simple cuboidal epithelial cells line the ducts of certain human exocrine glands. Various materials are transported into or out of the cells by diffusion. (The formula for the surface area of a cube is 6 x S2, and the formula for the volume of a cube is S3, where S = the length of a side of the cube.)
Which of the following cube-shaped cells would be most efficient in removing waste by diffusion?
When DNA replicates, each strand of the original DNA molecule is used as a template for the synthesis of a second, complementary strand. Which of the following figures most accurately illustrates enzyme-mediated synthesis of new DNA at a replication fork?
The following is a food web for a meadow habitat that occupies 25.6 km2. The primary products' biomass is uniformly distributed throughout the habitat and totals 1,500 kg/km2.
Developers have approved a project that will permanently reduce the primary producers' biomass by 50 percent and remove all rabbits and deer.
Which of the following is the most likely result at the completion of the project?
The biomass of coyotes will be 6 kg, and the biomass of hawks will be 0.5 kg.
The biomass of coyotes will be dramatically reduced.
The coyotes will switch prey preferences and outcompete the hawks.
There will be 50 percent fewer voles and 90 percent fewer hawks.
A pathogenic bacterium has been engulfed by a phagocytic cell as part of the nonspecific (innate) immune response. Which of the following illustrations best represents the response?
The diagram shows the progression of ecological events after a fire in a particular ecosystem. Based on the diagram, which of the following best explains why the oak trees are later replaced by other trees?
Eventually the other trees grow taller than the oak trees and form a dense canopy that shades the understory.
Oak trees alter the pH of the soil, making the forest better suited for shrubs and other trees.
Roots of shrubs proliferate in the soil of the forest and prevent the oak trees from obtaining water.
Oak trees succumb to environmental pollutants more readily than do either the shrubs or the other trees.
Lactose digestion in E. coli begins with its hydrolysis by the enzyme β-galactosidase. The gene encoding β-galactosidase, lacZ, is part of a coordinately regulated operon containing other genes required for lactose utilization.
Which of the following figures correctly depicts the interactions of the lac operon when lactose is NOT being utilized? (The legend defines the shapes of the molecules illustrated in the options.)
An experiment to measure the rate of respiration in crickets and mice at 10oC and 25oC was performed using a respirometer, an apparatus that measures changes in gas volume. Respiration was measured in mL of O2 consumed per gram of organism over several five-minute trials, and the following data were obtained.
During aerobic cellular respiration, oxygen gas is consumed at the same rate as carbon dioxide is produced. In order to provide accurate volumetric measurements of oxygen gas consumption, the experimental setup should include which of the following?
A substance that removes carbon dioxide gas
A plant to produce oxygen
A glucose reserve
A valve to release excess water
An experiment to measure the rate of respiration in crickets and mice at 10oC and 25oC was performed using a respirometer, an apparatus that measures changes in gas volume. Respiration was measured in mL of O2 consumed per gram of organism over several five-minute trials, and the following data were obtained.
According to the data, the mice at 10oC demonstrated greater oxygen consumption per gram of tissue than did the mice at 25oC. This is most likely explained by which of the following statements?
The mice at 10oC had a higher rate of ATP production than the mice at 25oC.
The mice at 10oC had a lower metabolic than the mice at 25oC.
The mice at 25oC weighed less than the mice at 10oC.
The mice at 25oC were more active than the mice at 10oC.
An experiment to measure the rate of respiration in crickets and mice at 10oC and 25oC was performed using a respirometer, an apparatus that measures changes in gas volume. Respiration was measured in mL of O2 consumed per gram of organism over several five-minute trials, and the following data were obtained.
According to the data, the crickets at 25oC have greater oxygen consumption per gram of tissue than do the crickets at 10oC. This trend in oxygen consumption is the opposite of that in the mice. The difference in trends in oxygen consumption among crickets and mice is due to their
relative size
mode of nutrition
mode of internal temperature regulation
mode of ATP production
Which of the following statements most directly supports the claim that different species of organisms use different metabolic strategies to meet their energy requirements for growth, reproduction, and homeostasis?
During cold periods pond-dwelling animals can increase the number of unsaturated fatty acids in their cell membranes while some plants make antifreeze proteins to prevent ice crystal formation in tissues.
Bacteria lack introns while many eukaryotic genes contain many of these intervening sequences.
Carnivores have more teeth that are specialized for ripping food while herbivores have more teeth that are specialized for grinding food.
Plants generally use starch molecules for storage while animals use glycogen and fats for storage.
Paramecia are unicellular protists that have contractile vacuoles to remove excess intracellular water. In an experimental investigation, paramecia were placed in salt solutions of increasing osmolarity. The rate at which the contractile vacuole contracted to pump out excess water was determined and plotted against osmolarity of the solutions, as shown in the graph. Which of the following is the correct explanation for the data?
At higher osmolarity, lower rates of contraction are required because more salt diffuses into the paramecia.
The contraction rate increases as the osmolarity decreases because the amount of water entering the paramecia by osmosis increases.
The contractile vacuole is less efficient in solutions of high osmolarity because of the reduced amount of ATP produced from cellular respiration.
In an isosmotic salt solution, there is no diffusion of water into or out of the paramecia, so the contraction rate is zero.
A student placed 20 tobacco seeds of the same species on moist paper towels in each of two petri dishes. Dish A was wrapped completely in an opaque cover to exclude all light. Dish B was not wrapped. The dishes were placed equidistant from a light source set to a cycle of 14 hours of light and 10 hours of dark. All other conditions were the same for both dishes. The dishes were examined after 7 days, and the opaque cover was permanently removed from dish A. Both dishes were returned to the light and examined again at 14 days. The following data were obtained.
According to the results of this experiment, germination of tobacco seeds during the first week is
increased by exposure to light
unaffected by light intensity
prevented by paper towels
accelerated in green-leaved seedlings
A student placed 20 tobacco seeds of the same species on moist paper towels in each of two petri dishes. Dish A was wrapped completely in an opaque cover to exclude all light. Dish B was not wrapped. The dishes were placed equidistant from a light source set to a cycle of 14 hours of light and 10 hours of dark. All other conditions were the same for both dishes. The dishes were examined after 7 days, and the opaque cover was permanently removed from dish A. Both dishes were returned to the light and examined again at 14 days. The following data were obtained.
The most probably cause for the difference in mean stem length between plants in dish A and plants in dish B is which of the following?
Shortening of cells in the stem in response to the lack of light
Elongation of seedlings in response to the lack of light
Enhancement of stem elongation by light
Genetic differences between the seeds
A student placed 20 tobacco seeds of the same species on moist paper towels in each of two petri dishes. Dish A was wrapped completely in an opaque cover to exclude all light. Dish B was not wrapped. The dishes were placed equidistant from a light source set to a cycle of 14 hours of light and 10 hours of dark. All other conditions were the same for both dishes. The dishes were examined after 7 days, and the opaque cover was permanently removed from dish A. Both dishes were returned to the light and examined again at 14 days. The following data were obtained.
Which of the following best supports the hypothesis that the difference in leaf color is genetically controlled?
The number of yellow-leaved seedlings in dish A on day 7
The number of germinated seeds in dish A on days 7 and 14
The death of all the yellow-leaved seedlings
The existence of yellow-leaved seedlings as well as green-leaved ones on day 14 in dish B
A student placed 20 tobacco seeds of the same species on moist paper towels in each of two petri dishes. Dish A was wrapped completely in an opaque cover to exclude all light. Dish B was not wrapped. The dishes were placed equidistant from a light source set to a cycle of 14 hours of light and 10 hours of dark. All other conditions were the same for both dishes. The dishes were examined after 7 days, and the opaque cover was permanently removed from dish A. Both dishes were returned to the light and examined again at 14 days. The following data were obtained.
Additional observations were made on day 21, and no yellow-leaved seedlings were found alive in either dish. This is most likely because
yellow-leaved seedlings were unable to absorb water from the paper towels
taller green-leaved seedlings blocked the light and prevented photosynthesis
yellow-leaved seedlings were unable to convert light energy to chemical energy
a higher rate of respiration in yellow-leaved seedlings depleted their stored nutrients
The endocrine system incorporates feedback mechanisms that maintain homeostasis. Which of the following demonstrates negative feedback by the endocrine system?
During labor, the fetus exerts pressure on the uterine wall, inducing the production of oxytocin, which stimulates uterine wall contraction. The contractions cause the fetus to further push on the wall, increasing the production of oxytocin.
After a meal, blood glucose levels become elevated, stimulating beta cells of the pancreas to release insulin into the blood. Excess glucose is then converted to glycogen in the liver, reducing blood glucose levels.
At high elevation, atmospheric oxygen is more scarce. In response to signals that oxygen is low, the brain decreases an individual's rate of respiration to compensate for the difference.
A transcription factor binds to the regulatory region of a gene, blocking the binding of another transcription factor required for expression.
Five species of bacteria were discovered in Antarctic ice core samples. The nucleotide (base) sequences of rRNA subunits were determined for the new species. The table shows the number of nucleotide differences between the species.
Which of the following phylogenetic trees is most consistent with the data?
The first diagram below shows the levels of mRNA from two different genes (bicoid and caudal) at different positions along the anterior-posterior axis of a Drosophila egg immediately before fertilization. The second diagram shows the levels of the two corresponding proteins along the anterior-posterior axis shortly after fertilization.
Which of the following conclusions is best supported by the data?
Bicoid protein inhibits translation of caudal mRNA.
Bicoid protein stabilizes caudal mRNA.
Translation of bicoid mRNA produces caudal protein.
Caudal protein stimulates development of anterior structures.
Sickle-cell anemia results from a point mutation in the HBB gene. The mutation results in the replacement of an amino acid that has a hydrophilic R-group with an amino acid that has a hydrophobic R-group on the exterior of the hemoglobin protein. Such a mutation would most likely result in altered
properties of the molecule as a result of abnormal interactions between adjacent hemoglobin molecules
DNA structure as a result of abnormal hydrogen bonding between nitrogenous bases
fatty acid structure as a result of changes in ionic interactions between adjacent fatty acid chains
protein secondary structure as a result of abnormal hydrophobic interactions between R-groups in the backbone of the protein
In a hypothetical population of beetles, there is a wide variety of color, matching the range of coloration of the tree trunks on which the beetles hide from predators. The graphs illustrate four possible changes to the beetle population as a result of a change in the environment due to pollution that darkened the tree trunks.
Which of the following includes the most likely change in the coloration of the beetle population after pollution and a correct rationale for the change?
The coloration range shifted toward more light-colored beetles, as in diagram I. The pollution helped the predators find the darkened tree trunks.
The coloration in the population split into two extremes, as in diagram II. Both the lighter-colored and the darker-colored beetles were able to hide on the darker tree trunks.
The coloration range became narrower, as in diagram III. The predators selected beetles at the color extremes.
The coloration in the population shifted toward more darker-colored beetles, as in diagram IV. The lighter-colored beetles were found more easily by the predators than were the darker-colored beetles.
Testosterone oxido-reductase is a liver enzyme that regulates testosterone levels in alligators. One study compared testosterone oxido-reductase activity between male and female alligators from Lake Woodruff, a relatively pristine environment, and from Lake Apopka, an area that has suffered severe contamination. The graph depicts the findings of that study.
The data in the graph best supports which of the following claims?
Environmental contamination elevates total testosterone oxido-reductase activity in females.
Environmental contamination reduces total testosterone oxido-reductase activity in females.
Environmental contamination elevates total testosterone oxido-reductase activity in males.
Environmental contamination reduces total testosterone oxido-reductase activity in males.
An individual's humoral response to a particular antigen differs depending on whether or not the individual has been previously exposed to that antigen. Which of the following graphs properly represents the humoral immune response when an individual is exposed to the same antigen more than once?
In a transformation experiment, a sample of E. coli bacteria was mixed with a plasmid containing the gene for resistance to the antibiotic ampicillin (ampr). Plasmid was not added to a second sample. Samples were plated on nutrient agar plates, some of which were supplemented with the antibiotic ampicillin. The results of E. coli growth are summarized below. The shaded area represents extensive growth of bacteria; dots represent individual colonies of bacteria.
Plates that have only ampicillin-resistant bacteria growing include which of the following?
I only
III only
IV only
I and II
In a transformation experiment, a sample of E. coli bacteria was mixed with a plasmid containing the gene for resistance to the antibiotic ampicillin (ampr). Plasmid was not added to a second sample. Samples were plated on nutrient agar plates, some of which were supplemented with the antibiotic ampicillin. The results of E. coli growth are summarized below. The shaded area represents extensive growth of bacteria; dots represent individual colonies of bacteria.
Which of the following best explains why there is no growth on plate II?
The initial E. coli culture was not ampicillin-resistant.
The transformation procedure killed the bacteria.
Nutrient agar inhibits E. coli growth.
The bacteria on the plate were transformed.
In a transformation experiment, a sample of E. coli bacteria was mixed with a plasmid containing the gene for resistance to the antibiotic ampicillin (ampr). Plasmid was not added to a second sample. Samples were plated on nutrient agar plates, some of which were supplemented with the antibiotic ampicillin. The results of E. coli growth are summarized below. The shaded area represents extensive growth of bacteria; dots represent individual colonies of bacteria.
Plates I and III were included in the experimental design in order to
demonstrate that the E. coli cultures were viable
demonstrate that the plasmid can lose its ampr gene
demonstrate that the plasmid is needed for E. coli growth
prepare the E. coli for transformation
In a transformation experiment, a sample of E. coli bacteria was mixed with a plasmid containing the gene for resistance to the antibiotic ampicillin (ampr). Plasmid was not added to a second sample. Samples were plated on nutrient agar plates, some of which were supplemented with the antibiotic ampicillin. The results of E. coli growth are summarized below. The shaded area represents extensive growth of bacteria; dots represent individual colonies of bacteria.
Which of the following statements best explains why there are fewer colonies on plate IV than on plate III?
Plate IV is the positive control.
Not all E. coli cells were successfully transformed.
The bacteria on plate III did not mutate.
The plasmid inhibits E. coli growth.
In a transformation experiment, a sample of E. coli bacteria was mixed with a plasmid containing the gene for resistance to the antibiotic ampicillin (ampr). Plasmid was not added to a second sample. Samples were plated on nutrient agar plates, some of which were supplemented with the antibiotic ampicillin. The results of E. coli growth are summarized below. The shaded area represents extensive growth of bacteria; dots represent individual colonies of bacteria.
In a second experiment, the plasmid contained the gene for human insulin as well as the ampr gene. Which of the following plates would have the highest percentage of bacteria that are expected to produce insulin?
I only
III only
IV only
I and III
Experimental evidence shows that the process of glycolysis is present and virtually identical in organisms from all three domains, Archaea, Bacteria, and Eukarya. Which of the following hypotheses could be best supported by this evidence?
All organisms carry out glycolysis in mitochondria.
Glycolysis is a universal energy-releasing process and therefore suggests a common ancestor for all forms of life.
Across the three domains, all organisms depend solely on the process of anaerobic respiration for ATP production.
The presence of glycolysis as an energy-releasing process in all organisms suggests that convergent evolution occurred.
A human kidney filters about 200 liters of blood each day. Approximately two liters of liquid and nutrient waste are excreted as urine. The remaining fluid and dissolved substances are reabsorbed and continue to circulate throughout the body. Antidiuretic hormone (ADH) is secreted in response to reduced plasma volume. ADH targets the collecting ducts in the kidney, stimulating the insertion of aquaporins into their plasma membranes and an increased reabsorption of water.
If ADH secretion is inhibited, which of the following would initially result?
The number of aquaporins would increase in response to the inhibition of ADH.
The person would decrease oral water intake to compensate for the inhibition of ADH.
Blood filtration would increase to compensate for the lack of aquaporins.
The person would produce greater amounts of dilute urine.
The diagram shows a developing worm embryo at the four-cell stage. Experiments have shown that when cell 3 divides, the anterior daughter cell gives rise to muscle and gonads and the posterior daughter cell gives rise to the intestine. However, if the cells of the embryo are separated from one another early during the four-cell stage, no intestine will form. Other experiments have shown that if cell 3 and cell 4 are recombined after the initial separation, the posterior daughter cell of cell 3 will once again give rise to normal intestine. Which of the following is the most plausible explanation for these findings?
A cell surface protein on cell 4 signals cell 3 to induce formation of the worm's intestine.
The plasma membrane of cell 4 interacts with the plasma membrane of the posterior portion of cell 3, causing invaginations that become microvilli.
Cell 3 passes an electrical signal to cell 4, which induces differentiation in cell 4.
Cell 4 transfers genetic material to cell 3, which directs the development of intestinal cells.
The tiny blue-eyed Mary flower is often one of the first flowers seen in the spring in some regions of the United States. The flower is normally blue, but sometimes a white or pink flower variation is found.
The following data were obtained after several crosses.
Which of the following statements best explains the data?
The appearance of blue in the F1 generation of the pink and white cross demonstrates that flower color is not an inherited trait but is determined by the environment.
Flower color depends on stages of flower development, and young flowers are white, advancing to pink and then blue.
Since the F1 and F2 phenotypes of the pink and white cross do not fit the expected genotypic and phenotypic ratios, blue-eyed Mary must reproduce by vegetative propagation.
Flower color is an inherited trait, and the F1 and F2 phenotypes of the flowers arising from the pink and white cross can best be explained by another gene product that influences the phenotypic expression.
Both myoglobin and hemoglobin are proteins that bind reversibly with molecular oxygen. The graph shows the oxygen-binding saturation of each protein at different concentrations of oxygen.
Which of the following statements is correct?
At 10 mm Hg partial pressure, hemoglobin binds oxygen but myoglobin does not.
At 20 mm Hg partial pressure, myoglobin and hemoglobin bind oxygen in equal amounts.
At 40 mm Hg partial pressure, myoglobin has a greater affinity for oxygen than hemoglobin has.
At 80 mm Hg partial pressure, myoglobin binds twice as much oxygen as hemoglobin does.
Both myoglobin and hemoglobin are proteins that bind reversibly with molecular oxygen. The graph shows the oxygen-binding saturation of each protein at different concentrations of oxygen.
Strenuous exercise lowers the blood pH, causing the curves for both hemoglobin and myoglobin to shift to the right. This shift results in
an unloading of O2 at higher partial pressures
an increase in the number of O2-binding sites
the capture of more O2 by hemoglobin
the capture of more O2 by myoglobin
Both myoglobin and hemoglobin are proteins that bind reversibly with molecular oxygen. The graph shows the oxygen-binding saturation of each protein at different concentrations of oxygen.
Which of the following best describes the physiological significance of the different oxygen-binding capabilities of hemoglobin and myoglobin?
They prevent muscles from depleting oxygen levels in the blood.
They cause muscles to become anaerobic.
They prevent glycogen depletion in muscles.
They enhance movement of oxygen from the blood into the muscles.
The chemical reaction for photosynthesis is
6 CO2 + 12 H2O + light energy --> C6H12O6 + 6 O2 + 6 H2O
If the input water is labeled with a radioactive isotope of oxygen, 18O, then the oxygen gas released as the reaction proceeds is also labeled with 18O. Which of the following is the most likely explanation?
During the light reactions of photosynthesis, water is split, the hydrogen atoms combine with the CO2, and the oxygen gas is released.
During the light reactions of photosynthesis, water is split, removing electrons and protons, and oxygen gas is released.
During the Calvin cycle, water is split, regenerating NADPH from NADP+, and oxygen gas is released.
During the Calvin cycle, water is split, the hydrogen atoms are added to intermediates of sugar synthesis, and oxygen gas is released.
A group of students summarized information on five great extinction events.
The students are sampling a site in search of fossils from the Devonian period. Based on the chart, which of the following would be the most reasonable plan for the students to follow?
Searching horizontal rock layers in any class of rock and trying to find those that contain the greatest number of fossils
Collecting fossils from rock layers deposited prior to the Permian period that contain some early vertebrate bones
Looking in sedimentary layers next to bodies of water in order to find marine fossils of bivalves and trilobites
Using relative dating techniques to determine the geological ages of the fossils found so they can calculate the rate of speciation of early organisms
Anabaena is a simple multicellular photosynthetic cyanobacteirum. In the absence of fixed nitrogen, certain newly developing cells along a filament express genes that code for nitrogen-fixing enzymes and become nonphotosynthetic heterocysts. The specialization is advantageous because some nitrogen-fixing enzymes function best in the absence of oxygen. Heterocysts do not carry out photosynthesis but instead provide adjacent cells with fixed nitrogen, in exchange receiving fixed carbon and reduced energy carriers.
As shown in the diagram, when there is low fixed nitrogen in the environment, an increase in the concentration of free calcium ions and 2-oxyglutarate stimulates the expression of genes that produce two transcription factors (NtcA and HetR) that promote the expression of genes responsible for heterocyst development. HetR also causes production of a signal, PatS, that prevents adjacent cells from developing as heterocysts.
Based on your understanding of the ways in which signal transmission mediates cell function, which of the following predictions is most consistent with the information given above?
In an environment with low fixed nitrogen, treating the Anabaena cells with a calcium-binding compound should prevent heterocyst differentiation.
A strain that overexpresses the patS gene should develop many more heterocysts in a low fixed nitrogen environment.
In an environment with abundant fixed nitrogen, free calcium levels should be high in all cells so that no heterocysts develop.
In environments with abundant fixed nitrogen, loss of the hetR gene should induce heterocysts development.
The figure shows several steps in the process of bacteriophage transduction in bacteria. Which of the following explains how genetic variation in a population of bacteria results from this process?
Bacterial proteins transferred from the donor bacterium by the phage to the recipient bacterium recombine with genes on the recipient's chromosome.
The recipient bacterium incorporates the transduced genetic material coding for phage proteins into its chromosome and synthesizes the corresponding proteins.
The phage infection of the recipient bacterium and the introduction of DNA carried by the phage cause increased random point mutations of the bacterial chromosome.
DNA of the recipient bacterial chromosome undergoes recombination with DNA introduced by the phage from the donor bacterium, leading to a change in the recipient's phenotype.
Figure I shows the growth of an algal species in a flask of sterilized pond water. If phosphate is added as indicated, the growth curve changes as shown in Figure II.
Which of the following is the best prediction of the algal growth if nitrate is added instead of phosphate?
