AP Bio 2015

30. Comparison of DNA sequences in Table II suggests that a functional GULO gene in lemurs can have a G, C, or T at position 21 but only a G at position 22. Which of the following pairs of predictions is most helpful in explaining the discrepancy?

(A)

33. Which of the following phylogenetic trees best illustrates (with the X) the point at which the mutation in the GULO gene most likely occurred during the evolutionary history of these organisms?

(A)

8. Which of the following graphs is the most appropriate representation of the experimental data?

(A)

50. Based on the information presented, which of the following genetic changes in an individual without diabetes is most likely to result in a disrupted cellular response to insulin signaling similar to that of an individual with type 2 diabetes? (A) A deletion in the gene encoding the insulin receptor that removes only the cytoplasmic domain of the protein (B) Duplication of the gene encoding a PI-3 kinase that results in synthesis of a muscle- specific variant of the enzyme in skin cells as well as in muscle cells (C) A mutation in the gene encoding IRS-1 that causes the protein to be active in muscle cells even in the absence of insulin signaling (D) Insertion of a small segment of DNA into the promoter of the Glut4 gene that results in increased synthesis of GLUT4 proteins in muscle cells

(A) A deletion in the gene encoding the insulin receptor that removes only the cytoplasmic domain of the protein

43. The gene sequences responsible for the iron - mediated changes in ferritin protein levels are highly conserved and are called iron response elements (IREs). IREs have been observed in a number of genes involved in iron transport and metabolism. The IRE sequences found in the ferritin gene are found in all multicellular organisms, whereas other nonferritin IRE sequences are found only in certain vertebrate organisms. Which of the following is the best explanation for the observations? (A) Ferritin IREs arose in the common ancestor of multicellular organisms, whereas nonferritin IREs arose later in specific evolutionary lineages. (B) Nonferritin IREs arose at different times in the common ancestor of multicellular organisms. (C) Ferritin IREs arose in diverse organisms by convergent evolution, while the nonferritin IREs arose by recombination events between closely related species. (D) Ferritin IREs have evolved independently in different evolutionary lineages, whereas nonferritin IREs arose in the common ancestor of multicellular organisms.

(A) Ferritin IREs arose in the common ancestor of multicellular organisms, whereas nonferritin IREs arose later in specific evolutionary lineages.

53. Which of the following statements is true regarding the movement of substances across cell membranes? (A) Ions are unable to move through the phospholipid bilayer because the nonpolar tail regions of the phospholipids are hydrophobic. (B) Ions are able to move through the phospholipid bilayer because the polar head regions of the phospholipids are charged. (C) Water is able to move through the phospholipid bilayer because the nonpolar tail regions of the phospholipids are charged. (D) Water is unable to move through the phospholipid bilayer because the polar head regions of the phospholipids are charged.

(A) Ions are unable to move through the phospholipid bilayer because the nonpolar tail regions of the phospholipids are hydrophobic.

42. The data can best be used to support which of the following claims about the mechanism for regulating ferritin gene expression? (A) Iron increases ribosome binding to ferritin mRNA. (B) Iron causes the ferritin mRNA to be degraded. (C) Iron increases the effect of actinomycin D on RNA polymerase. (D) Iron decreases the ability of ferritin mRNA to bind to ribosomes.

(A) Iron increases ribosome binding to ferritin mRNA.

The three-spined stickleback (Gasterosteus aculeatus) is a small fish found in both marine and freshwater environments. Marine stickleback populations consist mostly of individuals with pronounced pelvic spines, as shown in Figure 1. Individuals in freshwater stickleback populations, on the other hand, typically have reduced pelvic spines, as shown in Figure 2. 22. Which of the following describes a possible selective mechanism to explain why freshwater sticklebacks typically have reduced pelvic spines? (A) Reduced pelvic spines increase the likelihood of escaping predators in freshwater environments. (B) Reduced pelvic spines expand the range of foods that can be used as sources of energy in freshwater environments. (C) Reduced pelvic spines result in males becoming effectively invisible to potential mating partners in freshwater environments. (D) Reduced pelvic spines allow individual fish to pass through narrow waterways on their way to marine environments.

(A) Reduced pelvic spines increase the likelihood of escaping predators in freshwater environments.

37. In an experiment, the efficiency of oxygen exchange across the plasma membrane is being assessed in four artificial red blood cells. The table above lists some properties of those artificial cells. Other conditions being equal, which artificial cell is predicted to be the most efficient in exchanging oxygen with the environment by diffusion? (A) The cuboidal cell (B) The tetrahedral cell (C) The cylindrical cell (D) The spherical cell

(A) The cuboidal cell

46. Freshwater bony fish secrete large volumes of very dilute urine. Many marine bony fish secrete small volumes of concentrated urine. Which of the following best explains the differences in nitrogenous-waste excretion between freshwater and marine bony fish? (A) The differences arose during divergence, as fish from a common ancestor faced different selective pressures in environments of different osmolarity. (B) The differences resulted from the evolution of kidneys in independent evolutionary lineages that were adapted to different environmental conditions. (C) The differences are accidents of evolutionary divergence and are unrelated to the osmotic differences in freshwater and marine environments. (D) The differences arise in each generation because of the physiological adjustment of individual fish to fluctuating salt concentrations in the environments in which they live.

(A) The differences arose during divergence, as fish from a common ancestor faced different selective pressures in environments of different osmolarity.

34. The cells lining the respiratory tract of pigs have receptors for both avian and human influenza viruses. Based on the model above, which of the following best describes the origin of the new strain of human influenza virus? (A) The new viral strain inherited a mixture of genetic material from both avian influenza virus and human influenza virus. (B) The new viral strain inherited RNA molecules from the avian influenza virus and packaged them inside the human influenza virus membrane. (C) The new viral strain inherited a mutant DNA molecule from the pig respiratory tract cell. (D) The new viral strain inherited an RNA molecule that had recombined with a DNA molecule from the pig respiratory tract cell.

(A) The new viral strain inherited a mixture of genetic material from both avian influenza virus and human influenza virus.

48. Which of the following is a valid interpretation of the experimental results that explains how individuals with type 2 diabetes differ from individuals without diabetes? (A) The relatively low levels of glucose uptake in individuals with type 2 diabetes indicate that mobilization of GLUT4 to the cell surface is reduced in muscle cells of those individuals. (B) The relatively low levels of glucose uptake in individuals with type 2 diabetes indicate that no functional GLUT4 protein is produced in the muscle cells of those individuals. (C) The absence of activated insulin receptors in individuals with type 2 diabetes indicates that no insulin is secreted by the pancreatic cells of those individuals. (D) The absence of activated IRS-1 in individuals with type 2 diabetes indicates that no functional insulin receptor protein is produced in the muscle cells of those

(A) The relatively low levels of glucose uptake in individuals with type 2 diabetes indicate that mobilization of GLUT4 to the cell surface is reduced in muscle cells of those individuals.

5. Prairie dogs are small mammals that live in large colonies in burrows in the ground. Prairie dogs that are near their own relatives when a predator approaches are much more likely to issue a warning bark than those that are near unrelated prairie dogs. The prairie dogs that hear a warning bark are more likely to hide in their burrows than to remain above ground. However, the prairie dog that gives the warning bark is putting itself at increased risk of being identified and killed by the predator. Which of the following presents the most likely evolutionary explanation for the behaviors described? (A) The warning bark changes the behavior of the related prairie dogs nearby, allowing the prairie dog's family to have increased survival and reproductive success. (B) The barking prairie dog chooses to warn other prairie dogs, leading to more prairie dogs living above ground. (C) The barking prairie dog is alerting unrelated prairie dogs to the predator, so it is not giving any advantage to its own relatives. (D) The failure of the individual to bark when surrounded by unrelated prairie dogs ensures survival of the individual.

(A) The warning bark changes the behavior of the related prairie dogs nearby, allowing the prairie dog's family to have increased survival and reproductive success.

10. The student analyzed the data from the investigation and concluded that the estimate of the mean of one treatment group was unreliable. Which of the following identifies the treatment group most likely to have provided an unreliable estimate of the mean, and correctly explains why the estimate appears unreliable? (A) Treatment group II; it has a lower than expected mean absorbance and the largest standard error of the mean. (B) Treatment group III; it has a higher than expected mean absorbance and the largest standard error of the mean. (C) Treatment group IV; it has a higher than expected mean absorbance and the smallest standard error of the mean. (D) Treatment group V; it has a lower than expected mean absorbance and the smallest standard error of the mean.

(A) Treatment group II; it has a lower than expected mean absorbance and the largest standard error of the mean.

9. The illustration above is a model of a typical beet the estimate appears unreliable? root cell. Based on the experimental results, which of the following best represents the effect of acetone on the permeability of cellular membranes?

(B)

Mutations in DNA are usually caused by chemical or radiation damage to DNA molecules, followed by imperfect repair of the damage. Immediately after this kind of imperfect repair, there may be a mismatched base pair in the DNA. The illustration below shows an example of a mismatch, with the relevant pair bases in bold. Which of the following best represents the DNA of the two daughter cells produced when a bacterial cell with this particular mismatch replicates its DNA and divides?

(B)

38. To test the hypothesis that a particular plant synthesizes storage lipids by using glyceraldehyde 3-phosphate (G3P) from photosynthesis, a researcher plans to use radiolabeled precursors to track the molecules through the biosynthetic pathway. Which of the following radiolabeled precursors is most appropriate for the researcher to use? (A) 15N-labeled N2, because atmospheric nitrogen is fixed to amino acids by photosynthesis (B) 14C-labeled CO2, because atmospheric carbon is fixed to carbohydrates by photosynthesis (C) 35S-labeled methionine, because amino acids are incorporated into lipids during photosynthesis (D) 32P-labeled phosphate, because lipids are stored in plants as phospholipids

(B) 14C-labeled CO2, because atmospheric carbon is fixed to carbohydrates by photosynthesis

The three-spined stickleback (Gasterosteus aculeatus) is a small fish found in both marine and freshwater environments. Marine stickleback populations consist mostly of individuals with pronounced pelvic spines, as shown in Figure 1. Individuals in freshwater stickleback populations, on the other hand, typically have reduced pelvic spines, as shown in Figure 2. 19. Which of the following best describes how sticklebacks in the same population with identical copies of the Pitx1 gene can still show phenotypic variation in the pelvic spine character? (A) The Pitx1 gene is carried on different chromosomes in different individuals. (B) Expression of the Pitx1 gene is affected by mutations at other genetic loci. (C) The genetic code of the Pitx1 gene is translated differently in males and females. (D) The subcellular location of the Pitx1 gene changes when individuals move to a new environment.

(B) Expression of the Pitx1 gene is affected by mutations at other genetic loci.

17. Which of the following best supports the claim that organisms of different domains share a common ancestor? (A) Photosynthesis occurs in chloroplasts, and the citric acid cycle occurs in mitochondria. (B) Glycolysis occurs in both prokaryotic cells and eukaryotic cells. (C) Introns are present in eukaryotic DNA but not in prokaryotic DNA. (D) Errors in DNA synthesis provide some of the genetic variation in a population.

(B) Glycolysis occurs in both prokaryotic cells and eukaryotic cells.

14. Liver cells manufacture glycoproteins, while adipose cells store fat. Which of the following subcellular structures is likely to be more prominent in liver cells than in adipose cells? (A) Nucleus (B) Golgi apparatus (C) Cytoskeleton (D) Plasma membrane

(B) Golgi apparatus

26. The brain coordinates the circulatory and respiratory systems of the human body. The control of breathing, for example, involves neural pathways among the structures represented in the figure above. One important stimulus in the control of breathing is an increase in blood CO2 concentration, which is detected as a decrease in blood pH. Which of the following best describes the physiological response to an overall increase in cellular respiration in the body? (A) In response to depleted blood CO2 levels, the pH sensors send signals directly to the rib muscles, resulting in an increase in the rate of CO2 uptake by the lungs and a decrease in CO2 utilization by the brain. (B) In response to low blood pH, the pH sensors send a signal to the brain, which then sends a signal to the diaphragm, resulting in an increased rate of breathing to help eliminate excess blood CO2 . (C) In response to high blood pH, the pH sensors send a signal directly to the lungs, resulting in a slower rate of breathing, and the lungs send a signal back to the heart once CO2 availability has been restored. (D) In response to an increased rate of breathing, the rib muscles send a signal to the brain, which then sends a signal to the heart, resulting in a decrease in heart activity and slower flow of blood through the body.

(B) In response to low blood pH, the pH sensors send a signal to the brain, which then sends a signal to the diaphragm, resulting in an increased rate of breathing to help eliminate excess blood CO2 .

40. Which of the following biotechnology approaches could be used to identify ferritin mRNA in a sample of total cellular RNA? (A) RNA samples could be directly cloned into a DNA plasmid, grown in bacteria, and tested for the ability to bind iron. (B) RNA samples could be separated by size using agarose gel electrophoresis and incubated with labeled single-stranded DNA molecules that are complementary to the ferritin mRNA. (C) RNA samples could be converted to protein and subsequently cut with a restriction endonuclease that recognizes DNA sequences. (D) RNA samples could be examined under a high-power microscope to visually identify the ferritin mRNA.

(B) RNA samples could be separated by size using agarose gel electrophoresis and incubated with labeled single-stranded DNA molecules that are complementary to the ferritin mRNA.

44. Hereditary hemochromatosis (HHC) is an iron storage disease that results in reduced uptake of iron into cells. Based on the data, which of the following is the most likely effect of HHC on ferritin protein levels? (A) Elevated levels of ferritin protein because there is more iron in the blood of affected individuals (B) Reduced levels of ferritin protein because there is less iron in the cytosol of affected individuals (C) Elevated levels of ferritin protein because ferritin replaces the mutant protein in affected individuals (D) Reduced levels of ferritin protein because iron stimulates ferritin breakdown

(B) Reduced levels of ferritin protein because there is less iron in the cytosol of affected individuals

35. In the "RNA world" model for the origin of life, the first protocells (probionts) relied on RNA, not DNA, for information storage and transmission. Which of the following could best be considered evidence in support of the RNA world model? (A) DNA is more stable than is RNA. (B) Some RNA molecules in contemporary cells have catalytic function. (C) RNA is so complex in both structure and function that it must have preceded DNA. (D) RNA has secondary structure whereas DNA does not.

(B) Some RNA molecules in contemporary cells have catalytic function.

47. Malaria is caused by several different species of Plasmodium, a protozoan parasite. Plasmodium resistance to the common drugs used to treat malaria has increased in recent years. In a scientific study, Plasmodium samples were analyzed in blood drawn from a large number of infected patients before drug treatment and subsequently from the subset of infected patients with drug-resistant Plasmodium. DNA sequences of four different Plasmodium genes thought to be involved in resistance were compared between samples from patients with drug-sensitive Plasmodium and patients with drug-resistant Plasmodium. Which of the following best supports the hypothesis that preexisting mutations confer drug resistance? (A) Drug resistance can sometimes be reversed by simultaneous treatment with a drug that inhibits the drug-pumping mechanism of Plasmodium. (B) Some of the mutations that occur most frequently in samples from patients treated with antimalarial drugs are detectable in Plasmodium samples collected prior to use of antimalarial drugs. (C) Continued use of the same antimalarial drugs leads to increased Plasmodium resistance. (D) The same mechanism of drug resistance in Plasmodia isolated from separate populations of patients resulted from an accumulation of new genetic mutations.

(B) Some of the mutations that occur most frequently in samples from patients treated with antimalarial drugs are detectable in Plasmodium samples collected prior to use of antimalarial drugs.

31. Which of the following is the most likely effect of the mutation at nucleotide position 7 in the GULO gene of humans? (A) The mutation results in the deletion of the GULO gene, so no polypeptide can be translated. (B) The deletion of the single nucleotide causes a frame shift, changing the primary structure downstream of the mutation and resulting in a nonfunctional protein. (C) The point mutation causes a substitution of the amino acid isoleucine (Ile) for histidine (His) at position 7, resulting in a protein with higher than normal activity. (D) The substitution of a single nucleotide in the GULO coding region results in a stop codon. This results in a smaller nonfunctional protein.

(B) The deletion of the single nucleotide causes a frame shift, changing the primary structure downstream of the mutation and resulting in a nonfunctional protein.

13. In an experiment, 100 mice were released into a field to which no other mice had access. Immediately after their release, a representative sample of mice was captured, their fur color was recorded, and they were returned to the field. After twenty years, a representative sample of mice was captured and the distribution of fur color was again recorded. Which of the following could best explain the change in fur color distribution, as shown in the table above? (A) The allele for black fur color is unstable, and over twenty years most of the black fur alleles mutated to become alleles for gray fur. (B) The field was primarily composed of light- colored soil and little vegetation, affording gray mice protection from predators. (C) Sexual selection led to increased mating frequency of black and brown versus gray and brown. (D) The gray mice were harder to catch, and so were underrepresented in the twenty-year sample.

(B) The field was primarily composed of light- colored soil and little vegetation, affording gray mice protection from predators.

51. Trypsinogen is split by the enzyme enterokinase to form an activated molecule of the protease trypsin. Which of the following would confirm that the activation of trypsin is an example of how a positive feedback mechanism can amplify a biological process? (A) The activated trypsin enzyme can use enterokinase as a substrate. (B) The trypsin produced by the reaction is capable of splitting and activating additional trypsinogen molecules. (C) If levels of trypsin were to get too high, the trypsin molecules would inhibit the enzyme enterokinase. (D) Each mRNA molecule that codes for trypsinogen can be translated repeatedly to form many peptide molecules.

(B) The trypsin produced by the reaction is capable of splitting and activating additional trypsinogen molecules.

41. In individuals with iron-rich diets, intracellular levels of iron are higher than in individuals with iron-poor diets. Which of the following best explains how organisms regulate ferritin protein levels in response to available iron? (A) Translation of ferritin mRNA is inhibited in the presence of iron. (B) Translation of ferritin mRNA is stimulated by iron. (C) Ferritin protein is more stable in the presence of iron. (D) Ferritin protein is less stable in the presence of iron.

(B) Translation of ferritin mRNA is stimulated by iron.

1. A genetic counselor is consulted by a youngman ​who is worried about developing Huntington's disease, an inherited disorder caused by a dominant allele of a single gene. The young man explains that his cousin was recently diagnosed with Huntington's disease, and the news has caused him to consider his own risk of developing the disorder. Which of the following questions will best help the genetic counselor to evaluate the risk of the young man developing Huntington's disease and transmitting it to his children? (A) Were you and your cousin born in the same geographical area? (B) Were your parents or grandparents ever diagnosed with Huntington's disease? (C) Were you in physical contact with a person diagnosed with Huntington's disease? (D) Were you ever exposed to substances that are suspected of being mutagens?

(B) Were your parents or grandparents ever diagnosed with Huntington's disease?

1. Based on the data from the investigation, which of the following is the best scientific question about organisms living in water that is polluted with organic solvents? (A) Do organisms without pigments have a selective advantage in polluted environments? (B) Will organisms living in polluted environments exhibit detrimental effects from an increased permeability of their cellular membranes? (C) Will organic solvents from the environment become incorporated into the cell membranes of organisms living in polluted environments? (D) Should governments place more stringent restrictions on the release of organic solvents into aquatic ecosystems?

(B) Will organisms living in polluted environments exhibit detrimental effects from an increased permeability of their cellular membranes?12. Within a forest ecosystem, there is a large amount of diversity among members of a warbler species. Of the following stages of meiosis illustrated for a typical cell, which contributes most to diversity among the warblers?

25. The transmission of information from sensory neurons to interneurons typically involves the (A) exchange of electrons between specialized proteins embedded in the plasma membrane of the sensory neuron to the plasma membrane of the interneuron (B) release of chemical messengers into the space between the axon of the sensory neuron and the plasma membrane of the interneuron (C) transfer of a phosphate group from ATP in the sensory neuron to a protein substrate in the interneuron (D) flow of protons down an electrochemical gradient through a gated channel between the sensory neuron and the interneuron

(B) release of chemical messengers into the space between the axon of the sensory neuron and the plasma membrane of the interneuron

12. Within a forest ecosystem, there is a large amount of diversity among members of a warbler species. Of the following stages of meiosis illustrated for a typical cell, which contributes most to diversity among the warblers?

(C)

4. Which of the following describes a metabolic consequence of a shortage of oxygen in muscle cells? (A) An increase in blood pH due to the accumulation of lactic acid (B) No ATP production due to the absence of substrate-level phosphorylation (C) A buildup of lactic acid in the muscle tissue due to fermentation (D) A decrease in the oxidation of fatty acids due to a shortage of ATP

(C) A buildup of lactic acid in the muscle tissue due to fermentation

52. Cancer can result from a variety of different mutational events. Which of the following is LEAST likely to result in the initiation of a cancerous tumor? (A) A receptor mutation results in activation of a cell-division pathway in the absence of the appropriate ligand. (B) A mutation results in the loss of the ability to produce a tumor-suppressor protein. (C) A defect in a cell-cycle checkpoint prevents a cell from entering the S phase. (D) At the anaphase checkpoint, separation of chromatids occurs without all centromeres being attached to kinetochore microtubules from both poles.

(C) A defect in a cell-cycle checkpoint prevents a cell from entering the S phase.

24. Based on morphological characteristics, the phylogenetic tree above has been developed for species I, II, III, and IV. DNA sequencing has recently been completed for a particular gene found in all four species. The sequencing will provide additional information for answering which of the following questions? (A) Is species I the common ancestor of species II and III? (B) Does species I contain the greatest number of vestigial structures? (C) Are species III and IV the most closely related? (D) Should the positions of species III and IV be reversed?

(C) Are species III and IV the most closely related?

3. Lobe-finned fishes were present in the oceans of the world approximately 400 million years ago. The first tetrapods (vertebrates that had limbs and could move on land) date to about 365 million years ago. One hypothesis states that early tetrapods evolved from lobe-finned fishes. Which of the following is the best plan for testing the hypothesis? (A) Determining the number of fins found on lobe-finned fishes from different geographical locations (B) Measuring the proportion of radioisotopes found in fossils of early tetrapods (C) Comparing the arrangements of bones in the fins of lobe-finned fishes and limbs of the earliest tetrapods (D) Sequencing DNA isolated from fossils of lobe-finned fishes to determine the size of the genome

(C) Comparing the arrangements of bones in the fins of lobe-finned fishes and limbs of the earliest tetrapods

32. Lemurs are primates that live on the island of Madagascar off the coast of Africa. Lemurs have a functional GULO gene and are able to produce ascorbic acid. However, primates that live in other places (e.g., humans, chimpanzees, and orangutans) have a GULO pseudogene and are unable to produce ascorbic acid. Which of the following best explains the genetic variation among primate species? (A) Food sources on the island of Madagascar were deficient in ascorbic acid, which caused the primates to migrate to the mainland where ascorbic acid-rich foods are more widely available. (B) Human activity on Madagascar, including poaching, drove the other primates into extinction on the island. (C) Food sources where non-Madagascar primates lived provided ample ascorbic acid in the diet, which removed the selective pressure for maintaining a functional GULO gene. (D) Food sources on the island of Madagascar were deficient in ascorbic acid, which caused lemurs to adapt by developing the ability to produce an active GULO protein.

(C) Food sources where non-Madagascar primates lived provided ample ascorbic acid in the diet, which removed the selective pressure for maintaining a functional GULO gene.

23. Hydrangea macrophylla is a species of plant with blue or pink flowers. Flower color in Hydrangea macrophylla plants is thought to be determined primarily by soil conditions rather than by inherited differences. Which of the following will provide the most direct evidence that flower color in Hydrangea macrophylla is due primarily to soil conditions? (A) Comparing DNA sequence information for Hydrangea macrophylla to DNA sequence information for a different species of flowering plant (B) Performing a genetic cross between a pink- flowered plant and a blue-flowered plant and then determining the ratio of phenotypes in the offspring (C) Growing cuttings from the same Hydrangea macrophylla plant under controlled conditions that vary only with regard to soil pH (D) Analyzing fossilized remains of an ancestral species that grew in geographic areas similar to the habitats of modern Hydrangea macrophylla

(C) Growing cuttings from the same Hydrangea macrophylla plant under controlled conditions that vary only with regard to soil pH

6. One model of a sustainable fisheries practice is for individual fish to be removed from a natural population at a rate equal to the highest possible growth rate of an ideal population. The graph above represents a population of bluefin tuna living along the Atlantic coast. At which labeled point in the graph is the population growth rate the highest? (A) I (B) II (C) III (D) IV

(C) III

49. Based on the experimental results, which of the following describes the most likely defect in muscle cells of patients with type 2 diabetes? (A) Insulin receptor proteins do not reach the cell surface. (B) Insulin does not activate its receptor. (C) IRS-1 activation is reduced at high insulin concentrations. (D) GLUT4 blocks glucose from entering cells.

(C) IRS-1 activation is reduced at high insulin concentrations.

18. The graph below shows a model of population changes over time in a predator and its prey.Which of the following data would be most helpful in predicting possible disruptions to the relationship between the predator and its prey? (A) Time of day, because as days become shorter, nighttime hunting increases (B) Average birth weight of predators, because heavier offspring will begin hunting at younger ages (C) Numbers of additional predator species, because additional predators will increase competition for prey (D) Prey metabolic rates, because predators are less successful against prey with higher metabolic rates

(C) Numbers of additional predator species, because additional predators will increase competition for prey

15. Intravenous (IV) solutions administered to patients are normally isotonic. Which of the following is most likely if an IV of distilled water is administered to a patient? (A) The cells that are exposed to hypotonic solutions will shrink as a result of salt moving into the blood. (B) The liver will secrete additional bile salts into the blood to raise the tonicity of the administered fluid. (C) The cells that are exposed to hypotonic solutions will expand as water moves osmotically into the cells from the blood. (D) The patient's respiration rate will slow to compensate for the higher levels of circulating blood.

(C) The cells that are exposed to hypotonic solutions will expand as water moves osmotically into the cells from the blood.

16. The diagram above represents a typical rod- shaped bacterium. Which of the following best describes a feature shown in the diagram that is unique to archaea and bacteria? (A) The organism is surrounded by a cell wall. (B) The organism contains ribosomes. (C) The organism does not have a nuclear membrane surrounding its genetic material. (D) The organism is not capable of making or providing itself with ATP.

(C) The organism does not have a nuclear membrane surrounding its genetic material.

36. Which of the following pieces of evidence best supports the hypothesis that birds and crocodilians (crocodiles and alligators) are more closely related to each other than they are to other organisms? (A) Modern birds and crocodilians utilize different niches within the same geographical region. (B) Like turtles and snakes, modern birds and crocodilians build nests in which they lay shelled eggs. (C) The skulls of birds and crocodilians have an opening that is absent in the skulls of other reptiles. (D) Fossil evidence indicates that both modern birds and crocodilians originated during the Jurassic Period.

(C) The skulls of birds and crocodilians have an opening that is absent in the skulls of other reptiles.

45. The figure above shows a series of microscope images taken over time of ovalbumin production in chick oviduct cells in response to stimulation with estrogen. The ovalbumin protein was detected using a fluorescent dye as shown by the white areas in the time-lapse sequence. The microscope images indicate that ovalbumin (A) is synthesized on soluble ribosomes and packaged into lysosomes, from which it is secreted into the oviduct (B) is synthesized on ribosomes bound to the rough endoplasmic reticulum, and then secreted directly into the oviduct (C) crosses the endoplasmic reticulum membrane as it is translated, then moves to the Golgi apparatus, then to vesicles from which it is secreted (D) crosses the Golgi apparatus membrane post-translationally, is taken up by the Golgi apparatus and endoplasmic reticulum, then is packaged into secretory vesicles

(C) crosses the endoplasmic reticulum membrane as it is translated, then moves to the Golgi apparatus, then to vesicles from which it is secreted

28. The Stanley Miller apparatus demonstrated that organic molecules could assemble spontaneously in an environment lacking free oxygen and containing water, methane, and ammonia in the presence of an abundant energy source, such as an electric discharge. The research was considered supportive of the organic soup hypothesis, which states that the primitive atmosphere provided inorganic precursors from which organic molecules could have been synthesized in the presence of an energy source. Based on subsequent research, the primordial atmosphere was determined to contain less methane and more carbon dioxide. The new data about the composition of the early atmosphere had which of the following effects on origin-of-life hypotheses? (A) Miller's work was discarded as not relevant to an origin-of-life hypothesis. (B) Miller's work was used to refute the new hypothesis about the composition of the atmosphere. (C) The organic soup hypothesis was abandoned as no longer being supportable. (D) A new organic soup hypothesis was proposed to account for the new data about the atmosphere.

(D) A new organic soup hypothesis was proposed to account for the new data about the atmosphere.

2. Over several years, bacteria were isolated from members of a human population and tested for antibiotic resistance. The percent of bacterial isolates that were found to be antibiotic resistant is presented in the graph above for each year of the study. Which of the following conclusions is best supported by the information presented in the graph? (A) The greatest increase in antibiotic resistance occurred from the first year to the third year of the study. (B) Gene flow in the population occurred at the same rate for the entire duration of the eight-year study. (C) Because evolution in bacterial populations occurs over millions of years, the results are due to random variation. (D) Natural selection over multiple generations is favoring antibiotic resistance in the population of bacteria.

(D) Natural selection over multiple generations is favoring antibiotic resistance in the population of bacteria.

The three-spined stickleback (Gasterosteus aculeatus) is a small fish found in both marine and freshwater environments. Marine stickleback populations consist mostly of individuals with pronounced pelvic spines, as shown in Figure 1. Individuals in freshwater stickleback populations, on the other hand, typically have reduced pelvic spines, as shown in Figure 2. 20. A mutation that affects Pitx1 gene function in all tissue types is most likely to be at which of the following genetic loci? (A) Hindlimb enhancer (B) Pituitary enhancer (C) Jaw enhancer (D) Promoter

(D) Promoter

EFFECT OF WATER-SOLUBLE POLLUTANTS ON MEMBRANE PERMEABILITY 7. Which of the following is the dependent variable in the experiment? (A) The percent by volume of isopropanol in the treatment solutions (B) The percent by volume of water in the treatment solutions (C) The length of time each sample was incubated in the treatment solutions (D) The absorbance of 460 nm light by the treatment solutions

(D) The absorbance of 460 nm light by the treatment solutions

27. Thyroxin is a hormone that increases metabolic activities within various tissue targets. Low levels of circulating thyroxin trigger the secretion of thyroid-stimulating hormone (TSH) from the anterior pituitary. TSH secretion then stimulates thyroxin production and release by the thyroid gland. The increased level of circulating thyroxin inhibits further secretion of TSH from the anterior pituitary. Based on the information provided, which of the following can most likely be concluded about the TSH-thyroxin loop? (A) A person taking thyroxin to supplement low thyroxin secretion will produce more TSH. (B) Increased thyroxin production would cause elevated ribosomal activity in the anterior pituitary. (C) The structure of the loop would lead to elevated thyroid and tissue activity due to positive feedback. (D) The feedback mechanism would maintain relatively constant levels of thyroxin throughout tissue targets.

(D) The feedback mechanism would maintain relatively constant levels of thyroxin throughout tissue targets.

The three-spined stickleback (Gasterosteus aculeatus) is a small fish found in both marine and freshwater environments. Marine stickleback populations consist mostly of individuals with pronounced pelvic spines, as shown in Figure 1. Individuals in freshwater stickleback populations, on the other hand, typically have reduced pelvic spines, as shown in Figure 2. 21. In sticklebacks, which of the following is most likely to occur if the jaw enhancer is disabled instead of the hindlimb enhancer? (A) The jaw and a pronounced pelvic spine develop normally because the Pitx1 gene is expressed in both developing tissues. (B) Neither the jaw nor a pronounced pelvic spine develop normally because there is no Pitx1 gene expression in either developing tissue. (C) The jaw develops normally, but a pronounced pelvic spine does not develop because the Pitx1 gene is expressed in the developing jaw but not in the developing pelvis. (D) The jaw does not develop normally, but a pronounced pelvic spine does develop because the Pitx1 gene is expressed in the developing pelvis but not in the developing jaw.

(D) The jaw does not develop normally, but a pronounced pelvic spine does develop because the Pitx1 gene is expressed in the developing pelvis but not in the developing jaw.

Math answers

Question 121: 40-44 Question 122: 0 .12-0 .17 Question 123: 13 .5 Question 124: 9/16, .5625, .56, .562, .563 Question 125: 4 .9-5 .1