AP BIO 2013 Test

Which of the following statements best explains why there are fewer colonies on plate IV than on plate III?

(B) Not all E. coli cells are successfully transformed.

The following is a food web for a meadow habitat that occupies . The primary producers' biomass is uniformly distributed throughout the habitat and totals .

(B) The biomass of coyotes will be dramatically reduced.

Which of the following best explains why there is no growth on plate II?

(A) The initial E. coli culture was not ampicillin-resistant.

According to the data, the mice at demonstrated greater oxygen consumption per gram of tissue than did the mice at . This is most likely explained by which of the following statements?

(A) The mice at 10 degrees had a higher rate of ATP production than the mice at 25 .

According to the results of this experiment, germination of tobacco seeds during the first week is

(A) increased by exposure to light

The diagram above 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) A cell surface protein on cell 4 signals cell 3 to induce formation of the worm's intestine.

During aerobic cellular respiration, oxygen gas is consumed at the same rate as carbon dioxide gas is produced. In order to provide accurate volumetric measurements of oxygen gas consumption, the experimental setup should include which of the following?

(A) A substance that removes carbon dioxide gas

The diagram above 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?

(A) Eventually the other trees grow taller than the oak trees and form a dense canopy that shades the understory.

The endocrine system incorporates feedback mechanisms that maintain homeostasis. Which of the following demonstrates negative feedback by the endocrine system?

(B) 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.

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?

(B) Collecting fossils from rock layers deposited prior to the Permian period that contain some early vertebrate bones

The most probable cause for the difference in mean stem length between plants in dish A and plants in dish B is which of the following?

(B) Elongation of seedlings in response to the lack of light

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?

(B) The contraction rate increases as the osmolarity decreases because the amount of water entering the paramecia by osmosis increases.

33. Which of the following statements is correct?

(C) At partial pressure, myoglobin has a greater affinity for oxygen than hemoglobin has.

28. 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?

(C) IV only

Plates that have only ampicillin-resistant bacteria growing include which of the following

(C) IV only

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?

(C) The molecules essential to life today could have formed under early Earth conditions

According to the data, the crickets at 25 have greater oxygen consumption per gram of tissue than do the crickets at 10 . 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

(C) mode of internal temperature regulation

Additional observations were made on day 21, and no yellow-leaved seedlings were found alive in either dish. This is most likely because

(C) yellow-leaved seedlings were unable to convert light energy to chemical energy

The figure above 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?

(D) 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 genotype. AP Biology Exam Information

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.

(D) 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.

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 below 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.

(D) 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.

Which of the following best supports the hypothesis that the difference in leaf color is genetically controlled?

(D) The existence of yellow-leaved seedlings as well as green-leaved ones on day 14 in dish B

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?

(D) The person would produce greater amounts of dilute urine.

Which of the following best describes the physiological significance of the different oxygen-binding capabilities of hemoglobin and myoglobin?

(D) They enhance movement of oxygen from the blood into the muscles.

What happens in the light reactions?

A photon from the sun goes to the chlorophyll molecule which excites an electron into the excited state. It then releases heat and a photon when it goes back down to the ground state. Then it breaks H2O to get more hydrogen ions to replace the electron that is gone. O2 is released from that. As the electron moves through the thylakoid, H+ are pumped through the ATP synthase into the lumen to make ATP.

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 , and the formula for the volume of a cube is , 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?

A) 10 mum

Antidiuretic hormone (ADH) is important in maintaining homeostasis in mammals. ADH is released from the hypothalamus in response to high tissue osmolarity. In response to ADH, the collecting duct and distal tubule in the kidney become more permeable to water, which increases water reabsorption into the capillaries. The amount of hormone released is controlled by a negative feedback loop. Based on the model presented, which of the following statements expresses the proper relationship between osmolarity, ADH release, and urine production?

A) As tissue osmolarity rises, more ADH is released, causing less water to be excreted as urine

Which of the following descriptions of photosynthesis best explains the results of the experiment?

A) Availability of electrons for transfer to DCPIP depends on light energy.

Given that equal amounts of the different mRNAs were injected into fertilized frog eggs, which of the following conclusions is most consistent with the electrophoresis results?

A) B- hemoglobin mRNA is translated more efficiently then is a- hemoglobin mRNA

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

A) In an environment with low fixed nitrogen, treating the Anabaena cells with a calcium-binding compound should prevent heterocyst differentiation.

In 1944 Avery, Macleod, and McCarty performed transformation experiments using live, harmless bacteria and extracts from virulent bacteria treated with various enzymes. Which of the following enzymes were used and why?

A) Proteases and RNases to rule out protein and RNA as the transforming factors

A new mutation that aeose in one copy of gene in a somatic cells resulted in the formation of a tumor. Which of the following pieces of evidence best describes how the new mutation directly caused the tumor?

A) Protein normally stimulates cell division, and the mutation created an overactive version of protein X.

The restriction endonuclease Mst II recognizes the sequence 5′ CCT(N)AG (where N = any nucleotide) and cuts DNA at that site, producing separate fragments. Which of the following best explains the banding patterns exhibited in Figure 4 ?

A) The HbA DNA contains a recognition site for the Mst II restriction enzyme

Data regarding the presence (+) or absence (-) of five derived traits in several different species are shown in the table below. Which of the following cladograms provides the simplest and most accurate representation of the data in the table?

A) YWVZX (PICTURE)

Strenuous exercise lowers the blood pH, causing the curves for both hemoglobin and myoglobin to shift to the right. This shift results in

A) an unloading of at higher partial pressures

Plates I and III were included in the experimental design in order to

A) demonstrate that the E. coli cultures were viable

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?

A) graph w 2 peaks first one is shorter

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

A) properties of the molecule as a result of abnormal interactions between adjacent hemoglobin molecules

The divergence between the two populations of Rhagoletis must have occurred very rapidly because

A) the apple tree was imported into North America with European settlement approximately 200 years ago

A common laboratory investigation involves putting a solution of starch and glucose into a dialysis bag and suspending the bag in a beaker of water, as shown in the figure below. The investigation is aimed at understanding how molecular size affects movement through a membrane. Which of the following best represents the amount of starch, water, and glucose in the dialysis bag over the course of the investigation?

A) water, starch, glucose (GRAPH)

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.

A)Bicoid protein inhibits translation of caudal mRNA.

If the experiment was continued for an additional 500 days, the population density of T. castaneum with the parasite would most likely stabilize at a value closest to which of the following?

B) 10 beetles/culture dish

The vertebrate forelimb initially develops in the embryo as a solid mass of tissue. As development progresses, the solid mass near the end of the forelimb is remodeled into individual digits. Which of the following best explains the role of apoptosis in remodeling of the forelimb?

B) Apoptosis involves the regulated activation of proteins in specific cells of the developing

The electophoresis results best supports which of the following conculsions?

B) Cells from different tissues share a common ability to use genetic material from a foreign source to produce protein

Students in a class measured the mass of various living organisms. They then kept the organisms in the dark for 24 hours before remeasuring them. None of the organisms were provided with nutrients during the 24-hour period. The data are as follows. Which of the following is the best explanation for the pattern of change in mass of the organisms over time?

B) Cellular respiration

A dog is following the scent of a jackrabbit. Which of the following accurately describes how the dog's brain integrates information for smell?

B) Chemoreceptor cells in the nasal cavity sends impulses to the appropriate area of the brain.

Which of the following provides the best indication that light is required for the activation of electron transfer reactions in chloroplasts?

B) Comparing the observed results for sample 2 and sample 3

If the input water is labeled with a radioactive isotope of oxygen, , then the oxygen gas released as the reaction proceeds is also labeled with . Which of the following is the most likely explanation?

B) During the light reactions of photosynthesis, water is split, removing electrons and protons, and oxygen gas is released.

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 above depicts the findings of that study. The data in the graph best support which of the following claims?

B) Environmental contamination reduces total testosterone oxido-reductase activity in females

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?

B) Glycolysis is a universal energy-releasing process and therefore suggests a common ancestor for all forms of life.

Cystic Fibrosis is a reccesively inherited disorder that results from a mutation in the gene encoding CFTR chloride ion channels located on the surface of many epithelial cells. As shown in the figure above, the mutation prevents the normal movement of chloride ion channels from the cytosol of the cell to the extracellular fluid. An answer to which of the following questions would provide the best information about the association between the CFTR mutation and the viscous mucus?

B) How does the disrupted chloride movement affect the movement of sodium ions and water by the cell?

Which of the following questions is most relevant to understanding the Calvin cycle?

B) How is ATP used in the formation of 3-carbon carbohydrates?

Possessing a single copy of the HbS allele has been shown to provide some resistance to infection by Plasmodium falciparum, the parasite that causes malaria. Which of the following individuals represented in the pedigree would have the greatest selective advantage in an area where malaria is common?

B) II

The healthy human immune system responds to pathogens with both specific and nonspecific processes. Which of the following models depicts a nonspecific response?

B) Macrophage (PICTURE)

The data over the duration of the experiment provide the strongest support for which of the following conclusions regarding the effect of the parasite on Tribolium populations?

B) T. castaneum is adversely affected by the parasite, while T. confusum is not.

Initially, which of the following isolating mechanisms is likely to have been the most important in preventing gene flow between the two populations of Rhagoletis?

B) Temporal isolation

A group of mice was released into a large field to which no other mice had access. Immediately after the release, a representative sample of the mice was captured, and the fur color of each individual in the sample was observed and recorded. The mice were then returned to the field. After twenty years, another representative sample of the mice was captured, and the fur color of each individual in the sample was again recorded. Which of the following best explains the change in the frequency distribution of fur color phenotypes in the mouse population, as shown in the figures above?

B) The field was composed primarily of light-colored soil and little vegetation, affording gray mice

Undersea landslides can disrupt marine habitats by burying organisms that live on the ocean floor. The graph above shows the size of a population of a certain organism that lives on the ocean floor. The population was affected by a recent landslide at the time indicated on the graph. Which of the following best predicts how the population will be affected by the landslide?

B) The reduced population will likely have allelic frequencies that are different from the initial population.

Which of the following scientific questions could be investigated using a similar experimental setup?

B) What wavelength of light best activates electron transfer reactions in chloroplasts?

The processes illustrated in the models depicted above all result on which of the following?

B) an increase in genetic variation

Beaked whales feed at various depths, but they defecate at the oceans surface. Nitrogen- rich what feces deposited in surface waters supply nutrients for algae that are eaten by surface- dwelling fish. Which of the following best predicts what would happen if the whale population decreased?

B) the surface fish populations would decline due to reduced populations of algae

Five new 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 below shows the number of nucleotide differences between the species.

C) 3 4 2 5 1

Thrips are insects that feed on rose pollen. Scientists noted that the thrips population increased in the spring and decreased dramatically during the summer. The researchers hypothesized that food abundance was the limiting factor for the population. Which of the following types of data would be most useful for the scientists to collect at regular intervals on a designated test plot of rose plants?

C) Density of rose pollen produced (g/m2)

If ATP breakdown (hydrolysis) is inhibited, which of the following types of movement across cell membranes is also inhibited?

C) Passage of a solute against its concentration

Matings between individuals from the two populations of Rhagoletis produce hybrid flies that appear to be healthy and have normal life spans. The eggs laid by these hybrid flies, however, hatch less often than those of flies from either of the two populations. What isolating mechanism seems to be important in this hybrid population?

C) Reduced hybrid fertility

Under which of the following conditions is the observed number of beetles per culture dish the greatest?

C) T. castaneum with parasite at 100 days

If an additional sample containing the chloroplast/DCPIP solution was placed at a distance of 90 cm from the lamp, which of the following predictions would be most consistent with the experimental results?

C) The change in absorbance over time in the solution will be less than that of the other samples.

To determine the evolutionary history and relationships among organisms, scientists gather evidence from a wide variety of sources including paleontology, embryology, morphology, behavior, and molecular biology. A phylogenetic tree of vertebrates is shown. Which of the following statements is most consistent with the phylogenetic tree shown?

C) The common ancestor of reptiles, birds, and mammals produced amniotic eggs.

The diagram above depicts the response to a pinprick (stimulus) on the tip of a human finger. The arrows show the direction of impulse transmission along the labeled axons. If axon II was damaged before the pinprick, which of the following is most likely?

C) The person's finger will not withdraw reflexively.

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?

C) bacterium to lysosome out of the cell in pieces

if chemical signals in the cytoplasm control the progression of a cell to the M phase of the cell cycle, then fusion of a cell in G1 with a cell early M phase would most likely result in the

C) condensation of chromatin in preparation of \nuclear division in both cells.

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?

C) increase and level off

The data below demonstrate the frequency of tasters and nontasters of a certain compound in four isolated populations that are in Hardy-Weinberg equlibrium. The allele for nontasters is reccesive. In which population is the frequency of the recessive allele highest?

C) population: 3, Tasters: 215, Nontasters: 500, Size of population: 715

The figure above depicts the DNA- protein complex that is assembled at the transcriptional start site of gene X when the expression of gene X is activated in liver cells. Previous studies have shown that gene X is never expressed in nerve cells. Based on the diagram, which of the following is most likely contributes to the specific expression pattern of gene X? (PICTURE)

C) the activator is a sequence- specific DNA- binding protein that is present in some tissues but not in other tissues.

In the Arctic Ocean, the predominant primary producers are phytoplankton. Phytoplankton are consumed by zooplankton, which in turn are eaten by codfish. In years when there is more open water (less ice coverage), there are more zooplankton and fish than in years with less open water (more ice coverage). Based on the graph above, the difference is most likely because

C) the ice blocks the light, so in years with more ice coverage, there is less photosynthesis by the phytoplankton

Which of the following conclusions is most consistent with the results if the experiment?

C) the subunits of hemoglobin occur at a faster rate in in size, shape, or charge

Based on the data shown in Figure 1, which of the following best describes the genotypes of individual family members in the pedigree?

C)Healthy individuals may be still carriers of one mutant recessive allele (Hba) of the hemoglobin beta game

The Hbs allele, which causes sickle cell disease, results from a mutation in the DNA sequence shown in Figure 2 that produces a valine(val) in the place of a glutamic acid (glu) residue in the hemoglobin protein. Which of the following mRNA sequences is derived from the Hbs allele?

D) 5′ CUG ACU CCU GUG GAG AAG UCU 3′

The figure above shows a model of a ligand precursor being cleaved to produce an active ligand that binds to a specific receptor. Which of the following is most likely to reduce the binding of the active ligand to its receptor?

D) A mutation in the receptor gene that causes a substitution of a charged amino acid for a nonpolar amino acid in the ligand binding site of the receptor

H+ + HCO3- <-> H20 +CO2 The equation above shows one of the reversible reactions that occur in blood. After exercise, an athlete's blood pH has dropped below the normal level. How will normal blood pH be restored?

D) An increase in breathing rate will lead to a decrease in blood CO2 and H+ concentration.

Scientists have found that the existing populations of a certain species of amphibian are small in number, lacking in genetic diversity, and separated from each other by wide areas of dry land. Which of the following human actions is most likely to improve the long-term survival of the amphibians?

D) Building ponds in the areas of dry land to promote interbreeding between the separated populations

Which of the following can be reasonably concluded from the experimental results?.

D) Light from a lamp can substitute for sunlight in stimulating chloroplast processes

What most likely causes the trends in oxygen concentration shown in the graph above?

D) Photosynthesis produces more oxygen than is consumed by respiration during the day.

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?

D) Plants generally use starch molecules for storage while animals use glycogen and fats for storage.

Lactose digestion in E. coli begins with its hydrolysis by the enzyme . The gene encoding , lacZ, is part of a coordinately regulated operon containing other genes required for lactose utilization. Which of the following figures correctly depicts the interactions at the lac operon when lactose is NOT being utilized? (The legend below defines the shapes of the molecules illustrated in the options.)

D) Promoter to operator to LacZ to LacY to LacA

The observation that the rabbit mRNA was succesfully translated in the frog tissue supports which of the following conclusions

D) Rabbits and frogs share a common genetic conde for expressing heritable information

In Figure I, the difference between the two curves can best be attributed to which of the following?

D) The natural variation among populations

The diagram above illustrates the feedback control as exerted by the hormone thyroxine. Following surgical removal of the thyroid gland, the level of TSH in the blood will increase. Which of the following best explains this increase? (PICTURE)

D) a decrease in thyroxine levels means a loss in inhibition to the hypothalamus and anterior pituitary, leading to increased TSH secretion.

A student in biology class crossed a male Drosophilia melanogaster having gray body and long wings with a female D. melanogaster having a black body and apterous wings. The following distribution of traits was observed in the offspring. Which of the following is supported by the data?

D) genes for the 2 traits are located close together on the same chromosome, and crossing over occurred between the 2 gene loci

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?

D) in at 3' out at 5'

A researcher is investigating the relationship between the existing species diversity in a community and the ability of an introduced nonnative species to destabilize the community. Which of the following graphs is most consistent with the claim that communities with high diversity are more resistant to change than are communities with low diversity?

D) line going down (GRAPH)

Rosalind Franklin's x-ray diffraction images taken in the 1950s most directly support which of the following claims about DNA?

D) the basic molecular structure is a helix

Which of the following best justification for why the rabbit hemoglobin proteins were found throughout the tadpole?

D) the mRNA injected into the newly fertilized frog eggs is distributed in the cytoplasm of every daughter cell during cell division.

Ellis-van Creveld syndrome is a recessive genetic disorder that includes characteristics of short stature and extra fingers or toes. In the general population, this syndrome occurs in approximately 1 in 150000 live births. In a particular isolated population, however, the incidence of this syndrome among live births is 1 in 500. Assume that both the isolated population and the general population are in Hardy-Weinberg equilibrium with respect to this syndrome. Which of the following best describe the difference between the frequency of the allele that causes the syndrome in the general population and the frequency of the allele in the isolated population?

D. The frequency of the Ellis van Creveld allele is 0.0447 in the isolated population and 0.0026 in the general population, which suggests that genetic drift has occurered in the isolated population

Where does the oxygen come from in photosynthesis?

splitting of water