AP Biology Final

Which of the following proposes the best alternative hypothesis for the claim? A Climate analysis conducted by sampling pollen preserved in amber shows an increase in grass pollen 29 million years ago, but there is no significant difference between speciation rate, as well as species richness with regard to butterflies, before and after 29 million years ago. B Climate analysis conducted by sampling pollen preserved in amber shows an increase in grass pollen 29 million years ago, which indicates there was an increase in grasslands that correlates to an increase in butterfly speciation during the same time period. C There is a correlation between the rapid and wide-ranging decrease in species richness of insects in general 29 million years ago and the increase in species richness and diversity among the butterfly population during the same time period. D Evidence of rapid speciation among butterfly species 29 million years ago is evenly distributed among all environments of that period.

B

Which of the following claims is scientifically accurate and consistent with an observation that a decrease in lysosome production within a cell leads to a decline in mitochondrial activity? A A lack of lysosomes will cause a decrease in the synthesis of enzymes necessary for cellular respiration. B Fewer lysosomes will be available to break down macromolecules to provide the necessary nutrients for cellular respiration. C Fewer lysosomes will be available to store materials required for the functioning of the mitochondria. D Lysosomes will not be available to modify proteins so that they are targeted to the mitochondria.

B

Which of the following correctly explains the process shown in Figure 1 ? A DNADNA replication is occurring because replication is semi-conservative and the new strand is a copy of the template strand. B Initiation of transcription is occurring because a strand of RNARNA is being produced from a DNADNA template strand. C Translation is occurring because the two strands have separated and a new strand is being produced. D Alternative splicing of mRNAmRNA is occurring because the mRNAmRNA strand is being synthesized from only one strand of DNADNA.

B

Which of the following observations would best support the alternative hypothesis described above? A Plant cell walls are found just outside the plasma membrane, while fungal cell walls are found just beneath the plasma membrane. B In both plant cells and fungal cells, the cell wall surrounds the outside of the cell membrane. C Some plant cells have secondary cell walls that confer additional rigidity, while fungal cells do not. D Photosynthesis occurs in plant cells, but it does not occur in fungal cells.

B

Which of the following statements best helps justify the researcher's claim by providing a relevant example? A Rhizobia bacteria form close associations with the roots of bean plants. B E. coli bacteria reproduce in liquid media containing either glucose or galactose. C The antibiotic rifampicin inhibits the growth of some bacterial strains but not of others. D Some viruses that infect bacteria reproduce by either the lysogenic cycle or the lytic cycle.

B

Which of the stream types had a statistically lower macroscopic invertebrate species diversity than the seasonal streams? A Transitional streams only B Intermittent streams only C Perennial and intermittent streams only D Transitional and intermittent streams only

B

Which statement best helps explain the formation of the hydrogen bond represented in the figure? A The oxygen has a partial positive charge, and the nitrogen has a partial negative charge. B The nitrogen has a partial negative charge, and the hydrogen attached to the oxygen has a partial positive charge. C The hydrogen attached to the oxygen has a partial negative charge, and the nitrogen also has a partial negative charge. D The nitrogen has a partial positive charge, and the hydrogen attached to the oxygen also has a partial positive charge.

B

Based on the model, the newly synthesized protein is transported directly from the endoplasmic reticulum to which of the following? A The nucleus B The plasma membrane C The Golgi complex D The extracellular space

C

How would the extra chromosome affect the male offspring produced by the gamete? A None of the potential offspring would be male, because the potentially male zygote would have two XX chromosomes, and the YY chromosome would be ignored. B The male offspring would all be red-green color-blind, because of interference from alleles on the YY chromosome. C The male offspring would have full-color vision, because of the presence of the extra XX chromosome. D There would be no change to the phenotypes of the possible offspring, because the extra XX chromosome would not be active.

C

What is the maximum population growth rate (rmax) if the population grows to 283 in one year? A 0.12 B 0.13 C 0.35 D 0.39

C

Which of the following best describes the formation of the bond shown in Figure 1 ? A An ionic bond is formed between a carbon atom of one amino acid and the nitrogen atom of the other amino acid. B An ionic bond is formed when the negative charge of an OHOH group is balanced by the positive charge of a hydrogen ion. C A covalent bond is formed between a carbon atom and a nitrogen atom along with the formation of H2OH2O . D A covalent bond is formed that replaces the hydrogen bond between the OHOH group and the HH atom.

C

Which of the following best explains the directional shift in beak length in these birds? A Longer beaks allow the birds to better fend off predators. B Longer beaks increase the fitness of the birds in wild habitats. C Longer beaks allow the birds to better access seeds in bird feeders. D Longer beaks decrease the fitness of the birds in wild habitats.

C

Which of the following observations best supports the model? A Prokaryotes and eukaryotes acquire nutrients from the surrounding environment. B Organelles such as mitochondria and the endoplasmic reticulum have membranes composed of phospholipids. C Mitochondria and some prokaryotes share similar metabolic reactions that produce ATPATP. D Eukaryotes evolved after prokaryotes and have more complex structures.

C

Which of the following rows of data listed in table 1 best supports the possibility of a common ancestor for the organisms listed there? A Vascular tissue B Seeds enclosed in fruit C Cell wall composed of cellulose D Flagellated sperm cells

C

The observed differences between the groups most likely resulted from differences in the ability of the seedlings to produce which of the following monomers?

NCHR and weird one

Which of the following best depicts the tertiary structures of the two proteins in water? The diagrams in the options are not drawn to the same scale as those in Figure 1 and Figure 2.

original- ball, mutated- ball with one on top

Based on the model, what will be the mean diameter of the phytoplankton cells that are found 25 kilometers from shore? A 650 micrometers B 875 micrometers C 925 micrometers D 1150 micrometers

A

During prophase I replicated homologous chromosomes pair up and undergo synapsis. What testable question is generated regarding synapsis and genetic variability by Figure 1 ? A Is the distance between two gene loci related to crossover rate? B Does crossing over occur more often in some chromosomes than in others? C Is crossing over inhibited by methylation? D Is crossing over promoted by methylation?

A

Muscle cells have high ATP demands. Which of the following is a scientific claim about how the structure of the mitochondria in muscle cells should be different than it is in other cells because of the high energy demands of mitochondria? A The inner membrane of the mitochondria in muscle cells should have more folds to increase the surface area, allowing more ATPATP to be synthesized. B The inner membrane of the mitochondria in muscle cells should be more permeable to large enzymes, allowing the same reactions to occur in both compartments of the mitochondria. C The outer membrane of the mitochondria in muscle cells should be thicker, allowing more rapid diffusion of molecules into the mitochondria. D The outer membrane of the mitochondria of muscle cells should have more folds, increasing the surface area for faster diffusion of molecules from the cytoplasm.

A

Of the two cells represented in the figure, which would likely be more efficient at exchanging substances with the surrounding environment? A Cell A, because it has the larger surface-area-to-volume ratio. B Cell A, because it has the smaller surface-area-to-volume ratio. C Cell B, because it has the larger surface-area-to-volume ratio. D Cell B, because it has the smaller surface-area-to-volume ratio.

A

Researchers claim that bacteria that live in environments heavily contaminated with arsenic are more efficient at processing arsenic into arsenite and removing this toxin from their cells. Justify this claim based on the evidence shown in Figure 1. A There are multiple operons controlling the production of proteins that process and remove arsenite from cells in both H. arsenicoxydans and O. tritici. In contrast, E. coli has only one operon devoted to arsenic removal. B Both H. arsenicoxydans and O. tritici contain the arsRarsR gene that codes for a repressor that turns on the operon to eliminate arsenite from the cell. C Both O. tritici and E. coli contain the arsDarsD gene, which codes for a protein that helps remove arsenite from the cell. D Both H. arsenicoxydans and O. tritici. have more arsenic resistance genes than has E. coli.

A

Scientists have found that DNA methylation suppresses crossing-over in the fungus Ascobolus immersus. Which of the following questions is most appropriately raised by this specific observation? A Is the level of genetic variation in the gametes related to the amount of DNADNA methylation observed? B Without crossing-over, will gametes be viable and be able to produce zygotes? C Does DNADNA methylation result in shorter chromosomes? D Is this species of fungus a diploid organism?

A

The researcher claims that there is no selective advantage to fur color, so light and dark fur color phenotypes are present in similar frequencies in the fourth generation of this mouse population. Based on the data in Figure 1, which of the following best evaluates this null hypothesis? A The null hypothesis is rejected, because the change to a darker background color led to an increase in the dark-colored fur phenotype. B The null hypothesis is rejected, because there is no significant difference between the frequencies of the two phenotypes right after the human-caused change to the habitat in the third generation. C The null hypothesis cannot be rejected, because there is no significant difference between the frequencies of the two phenotypes right after the human-caused change to the habitat in the third generation. D The null hypothesis cannot be rejected, because the darker background color caused by the human-caused change to the habitat led to a decrease in the light fur color phenotype.

A

Which of the following best describes a process that occurs within the Golgi complex? A Enzymatic modification of newly synthesized integral membrane proteins B Synthesis of cytosolic proteins based on the nucleotide sequences of mRNAsmRNAs C Degradation of proteins by hydrolytic enzymes contained within the complex D Synthesis of various types of lipids

A

Which of the following best describes the numbered areas? A Areas 1 and 3 are polar, since the membrane molecules are aligned with water molecules. B Area 2 is polar, since water has been excluded from this area of the membrane. C Areas 1 and 3 are hydrophilic, since membrane molecules formed covalent bonds with water. D Area 2 is nonpolar, since hydrogen bonds between the adjacent lipids hold the membrane together.

A

Which of the following best explains how bacteria can be genetically engineered to produce a desired antigen? A The gene coding for the antigen can be inserted into plasmids that can be used to transform the bacteria. B The bacteria need to be exposed to the antigen so they can produce the antibodies. C The DNADNA of the antigen has to be transcribed in order for the mRNAmRNA produced to be inserted into the bacteria. D The mRNAmRNA of the antigen has to be translated in order for the protein to be inserted into the bacteria.

A

Which of the following best predicts the effect of inserting this gene into the DNA of a bacterial cell? A The recombinant bacterium will produce human insulin using its own transcription and translation machinery. B The recombinant bacterium will not transcribe the human insulin gene because this gene is not normally found in the bacterial genome. C The recombinant bacterium will transcribe the gene but will be unable to translate the mRNAmRNA. D The recombinant bacterium will die because it has been exposed to foreign DNADNA.

A

Which of the following best predicts the effect of not having ATP available to supply energy to this process? A H+H+ ions will stop moving through the protein. B H+H+ ions will move in the other direction through the protein. C H+H+ ions will continue to move through the protein in the original direction but at a slower rate. D H+H+ ions will begin to move through the phospholipid portion of the membrane in the original direction.

A

Which of the following observations would best support this alternative hypothesis? A Previous dips in plankton abundance coincided with other El Niño events. B Primary consumers also experienced a dip in abundance in early 1998. C After mid-1998, there is no correlation between phytoplankton and zooplankton abundance. D CO2CO2 levels in surface waters increased significantly in this region during 1998.

A

Which of the following should be included in an alternative hypothesis that would best support this claim? A The current extinction rate of amphibians compared with the background rate of extinction as determined by the fossil record B The extinction rate of amphibians in the 21st21st century compared with the extinction rate of amphibians during the 20th20th century C The number of species of amphibians currently alive compared with the number of amphibian species known to be extinct D The number of new amphibian species being discovered per year compared with the number of amphibian species becoming extinct during the same time period

A

Which of the following statements best justifies the inclusion of test tubes 3 and 7 in the experiment? A They will show whether the isolated cellular contents have enzymatic activity. B They will show whether environmental pHpH affects the function of the enzyme. C They will show the rate of product formation in the absence of bacterial factors. D They will show the rate of product formation in the absence of the substrate.

A

Which of the following statements provides the most reasonable prediction to account for the deviation from the expected results? A In sweet pea plants, the gene for flower color and the gene for pollen grain shape are genetically linked. B In sweet pea plants, the genes for flower color and for pollen grain shape both exhibit codominance. C Several mutations occurred spontaneously producing a deviation from the expected phenotypic ratios of the offspring. D The genes for flower color and pollen grain shape are inherited independently because of the law of independent assortment.

A

Which of the following, if true about the drug, best supports the alternative hypothesis that the new drug will exhibit simple diffusion across plasma membranes? A The drug is a small nonpolar molecule. B The drug is a small charged molecule. C The drug is a large polar molecule. D The drug is a large charged molecule.

A

Which organism would the researchers most likely predict to be the most distantly related to eukaryotes? A Organism I B Organism II C Organism III D Organism IV

A

Which statement best explains why correct protein folding is critical in the transmembrane protein shown above? A Interactions of the hydrophobic and hydrophilic amino acids help to anchor the protein in the membrane. B Interactions of the peptide bonds of the protein with the membrane will affect the rate at which substances can cross the membrane. C Interactions of the protein and phospholipids increase membrane fluidity. D Interactions of the quaternary structure of the protein will increase hydrogen bonding in the membrane and make the membrane less fluid.

A

Air is less dense at very high elevations, so less oxygen is available than in the denser air at sea level. Based on the model in Figure 1, if a person travels from sea level to a high elevation location, which of the following correctly predicts the response to the decreased blood oxygen level? A More erythropoietin will be secreted from the kidneys, decreasing production of erythrocytes. B More erythropoietin will be secreted from the kidneys, increasing production of erythrocytes. C Less erythropoietin will be secreted from the kidneys, decreasing production of erythrocytes. D Less erythropoietin will be secreted from the kidneys, increasing production of erythrocytes.

B

Based on Figure 1, which of the following statements best describes the epinephrine signaling pathway? A It involves the opening and closing of ion channels. B In involves enzymes activating other enzymes. C It involves changes in the expression of target genes. D It involves protons moving down a concentration gradient.

B

Based on the information presented, which of the following is the most likely explanation for a buildup of cholesterol molecules in the blood of an animal? A The animal's body cells are defective in exocytosis. B The animal's body cells are defective in endocytosis. C The animal's body cells are defective in cholesterol synthesis. D The animal's body cells are defective in phospholipid synthesis.

B

Based on the inheritance pattern shown in Figure 1, which of the following best predicts the nature of the original mutation? A A recessive mutation on the X chromosome B A recessive mutation on a somatic chromosome C A dominant mutation on the X chromosome D A dominant mutation on a somatic chromosome

B

Based on the model presented in Figure 1, which of the following outcomes will most likely result from a loss of protein X function? A The membrane potential will be disrupted by an increase in Na+Na+ concentration inside the cell. B The membrane potential will be disrupted by an increase in K+K+ concentration inside the cell. C The membrane potential will be maintained by the Na+−K+Na+⁢−⁢K+ pump moving more K+K+ ions into the cell. D The membrane potential will be maintained by the diffusion of Na+Na+ ions into the cell.

B

If the carrying capacity of the pond is 1,500 for this species, what is the expected population size after one year? A 167 B 417 C 450 D 500

B

Which of the following best describes a structural difference between DNA and RNA? A DNADNA contains four types of nitrogenous bases, whereas RNARNA contains only two types of nitrogenous bases. B The backbone of DNADNA contains deoxyribose, whereas the backbone of RNARNA contains ribose. C A DNADNA molecule is composed of two parallel strands with the same 5′5′ to 3′3′ directionality, whereas an RNARNA molecule is composed of only one 5′5′ to 3′3′ strand. D Phosphate groups provide rigidity to DNADNA, but RNARNA is flexible and contains no phosphate groups.

B

Which of the following best describes how amino acids affect the tertiary structure of a protein? A The number of amino acids determines the tertiary structure of the protein. B The interactions of the different RR-groups with other RR-groups and with their environment determine the tertiary structure of the protein. C The RR-group of the last amino acid that is added to a growing polypeptide chain determines the next amino acid that is added to the chain. D The sequence of the amino acids in the polypeptide chain determines the protein's primary structure but has no effect on its tertiary structure.

B

Which of the following best describes the effect of a greater number of cysteine amino acids on the stability of the proteins? A The change has no effect on the stability of the protein because only one type of amino acid is involved. B The change leads to increased protein stability because of an increased number of S-SS-S bonds in the tertiary structure of the proteins. C The change leads to decreased protein stability because of an increased number of S-SS-S bonds in the tertiary structure of the proteins. D The change leads to increased protein stability only when the added cysteine amino acids are next to other cysteine amino acids in the primary structure.

B

Which of the following best describes the structures of carbohydrates? A They only occur as disaccharides. B They occur as monomers, chains of monomers, and branched structures. C They only occur as long and branched structures. D They occur as chains of monomers that hydrogen bond with complementary chains of monomers.

B

Which of the following best explains what process is represented in Figure 1 ? A New DNADNA strands are being synthesized in the 3'3′ to 5'5′ direction from their DNADNA templates. B New DNADNA strands are being synthesized in the 5'5′ to 3'3′ direction from their DNADNA templates. C A new RNARNA strand is being synthesized in the 3'3′ to 5'5′ end from its DNADNA template. D Two new RNARNA strands are being synthesized in both directions from their DNADNA templates.

B

Which of the following best explains why this particular strain of bacteria is resistant to antibiotic treatment? A Mutations creating new alleles occur more frequently in this species of bacteria than in other species. B The bacteria have high genetic variability and high reproductive rates. C Crossing over during meiosis increased genetic variability in the bacteria. D The bacteria are able to recognize and destroy the antibiotics by breaking them down extracellularly.

B

Which of the following characteristics of Figure 1 best shows that the fragment is RNA and not DNA? A The 5′5′ to 3′3′ orientation of the nucleotide chain B The identity of each nitrogenous base C The charges on the phosphate groups D The type of bond linking the nucleotides together

B

Which of the following describes how the vent bacteria harvest energy to produce organic compounds for use by the vent community? A The bacteria use the heat from the hot water to assemble carbon-based materials from inorganic molecules. B The bacteria function as chemoautotrophs, extracting energy from hydrogen-rich inorganic molecules. C Organic matter drifting down from the ocean's surface is used to make molecules with enough energy to sustain the vent community. D The bacteria can recycle the energy from the waste products and dead material produced by the heterotrophs of the vent community into energy-rich carbon compounds that can be recycled.

B

Which of the following outcomes will most likely result from a loss of ion pump function in the cell's lysosomes? A The internal pHpH of the lysosomes will decrease, which will prevent the activation of hydrolytic enzymes and interfere with the intracellular digestion of food. B The internal pHpH of the lysosomes will increase, which will prevent the activation of hydrolytic enzymes and interfere with the intracellular digestion of food. C The internal pHpH of the lysosomes will decrease, which will activate hydrolytic enzymes and enhance the intracellular digestion of food. D The internal pHpH of the lysosomes will increase, which will activate hydrolytic enzymes and enhance the intracellular digestion of food.

B

Which of the following provides the best reasoning to justify the researcher's claim? A In green light, more chlorophyll a molecules are produced, reflecting more light to other cyanobacteria to be used for photosynthesis. B In green light, more phycoerythrin molecules are produced, allowing more green light to be absorbed, thus increasing photosynthesis. C In green light, cyanobacteria that have more phycocyanin molecules are less likely to survive and reproduce. D In green light, cyanobacteria that have more allophycocyanin molecules are more likely to survive and reproduce.

B

Which of the following statements best describes how organisms such as rabbits obtain the carbon necessary for building biological molecules? A Rabbits eat plants and use energy absorbed from the plants to make carbon atoms from electrons, protons, and neutrons in the air. B Rabbits eat plants and break down plant molecules to obtain carbon and other atoms that they rearrange into new carbon-containing molecules. C Rabbits eat plants and use water absorbed from the plants to hydrolyze CO2CO2, which the rabbits breathe in from the air and use as a carbon source. D Rabbits eat plants and make carbon-containing molecules by using carbon atoms that the plants absorbed from the soil and stored in the cells of their leaves.

B

Which of the following statements best explains the data set? A Since the %A%A and the %G%G add up to approximately 50 percent in each sample, adenine and guanine molecules must pair up in a double-stranded DNADNA molecule. B Since the %A%A and the %T%T are approximately the same in each sample, adenine and thymine molecules must pair up in a double-stranded DNADNA molecule. C Since the %(A+T)%(A+T) is greater than the %(G+C)%(G+C) in each sample, DNADNA molecules must have a poly-AA tail at one end. D Since the %C%C and the %T%T add up to approximately 50 percent in each sample, cytosine and thymine molecules must both contain a single ring.

B

Which of the following statements best explains the processes of passive and active transport? A Passive transport is the net movement of substances down a concentration gradient that requires metabolic energy. Active transport is the movement of substances up a concentration gradient that does not require energy. B Passive transport is the net movement of substances down a concentration gradient that does not require metabolic energy. Active transport is the movement of substances up a concentration gradient that requires energy. C Passive transport is the net movement of substances up a concentration gradient that requires metabolic energy. Active transport is the movement of substances down a concentration gradient that does not require metabolic energy. D Passive transport is the net movement of substances up a concentration gradient that does not require metabolic energy. Active transport is the movement of substances down a concentration gradient that requires energy.

B

Which of the following statements best helps explain how the enzyme speeds up the reaction? A The enzyme's active site binds to and stabilizes the reactant, which decreases the free-energy change of the reaction. B The enzyme's active site binds to and stabilizes the transition state, which decreases the activation energy of the reaction. C The enzyme's active site binds to and stabilizes the product, which increases the amount of energy released by the reaction. D The enzyme's active site binds to and stabilizes both the reactant and the product at the same time, which increases the reaction's equilibrium constant.

B

Which of the following statements best helps justify the researcher's claim? A ADPADP is a small molecule that some cells release into their environment as a way of communicating with other cells. B ATPATP hydrolysis is an energy-releasing reaction that is often coupled with reactions that require an input of energy. C Inorganic phosphate (Pi)(Pi) is a substance that cells typically acquire from their environment. D ATPATP synthase is a mitochondrial enzyme that catalyzes the conversion of ADPADP and PiPi to ATPATP.

B

Which of the following statements best predicts the effect of a mutation that results in a loss of the glucocorticoid receptor's ligand binding function? A The transduction of the glucocorticoid signal across the plasma membrane will be blocked. B The glucocorticoid receptor will remain associated with the accessory proteins. C The rate of diffusion of glucocorticoid molecules into the cell will increase. D The concentration of glucocorticoid receptors inside the nucleus will increase.

B

Which of the following statements describes a feature shared by mitochondria and the endoplasmic reticulum that increases the efficiency of their basic functions? A They have rigid, nonfluid membranes. B They have highly folded membranes. C They have membranes composed of many carbohydrates. D They have double membranes, with one membrane enclosed within the other.

B

Which statement best describes the effect on water transport across the cell membrane if the aquaporin in the figure ceases to function? A Water molecules will no longer be able to move across the cell membrane. B Water molecules will still be able to move across the cell membrane but at a slower rate. C Water molecules will only be able to enter the cell by active transport. D Water molecules will move across the cell membrane at a faster rate without the aquaporin regulating their flow.

B

Which statement best explains the orientation of the phospholipid molecules in this model? A The nonpolar portions of the phospholipid molecules are attracted to the internal and external environments. B The hydrophilic phosphate groups of the phospholipid molecules are attracted to the aqueous internal and external environments. C The embedded proteins attract the fatty acid tails of the phospholipids, so the tails point away from the internal and external aqueous environments. D The fatty acid tails of the phospholipid molecules are hydrophilic and are repelled by the internal and external aqueous environments.

B

An investigator wants to understand whether a newly found membrane protein is involved in membrane transport of a certain particle. Which investigation will help determine whether the new membrane protein is a channel protein involved in membrane transport? A Add small nonpolar molecules to the extracellular space and measure the direction of particle movement of the molecules. B Measure the rate of extracellular fluid movement into the intracellular space. C Add more of the proteins to the plasma membrane and measure the rate of the particle movement. D Remove ATPATP from the intracellular space and measure the rate of the particle movement into the intracellular space.

C

Based on the molecular structures shown in the figure, which molecule is likely to be solid at room temperature? A Linoleic acid, because the absence of carbon-carbon double bonds allows the molecules to pack closely together. B Linoleic acid, because the presence of carbon-carbon double bonds prevents the molecules from packing closely together. C Palmitic acid, because the absence of carbon-carbon double bonds allows the molecules to pack closely together. D Palmitic acid, because the presence of carbon-carbon double bonds prevents the molecules from packing closely together.

C

Which of the following best explains the differences in flower color of the African violets in the greenhouse? A Warmer temperatures result in genotypic alterations, which result in flower color differences. B The plants along the walls of the greenhouse are homozygous recessive and therefore have white flowers. C An enzyme responsible for flower color does not fold correctly in cooler temperatures, and the greenhouse is warmest in the center. D More light is available along the walls of the greenhouse, so the flowers need less pigment to absorb sunlight for photosynthesis.

C

Which of the following best explains the distribution of lactase persistence in the areas shown in Figure 1 ? A Lactase persistence developed because people were malnourished in Europe. B Lactase persistence alleles are present in all human populations and are expressed when lactose is consumed. C Mutations conferring lactase persistence likely arose independently in different geographic areas and offered a selective advantage. D The mutations that cause lactase persistence are detrimental to humans and will eventually disappear from the gene pool.

C

Which of the following best provides reasoning supporting a method that would help protect commercial banana crops from infection by pathogenic organisms such as Fusarium fungi? A The commercial banana strains should be exposed to XX-rays to encourage random mutations that will then be passed to offspring, producing resistance to pathogenic organisms. B The Cavendish banana plants should be exposed to pathogenic organisms under controlled conditions, so the plants can be encouraged to mutate and develop resistance to the pathogens. C The commercial banana strains should not be grown in monocultures, since many pathogenic organisms are able to evolve rapidly in response to a single selective pressure. D Growing the Cavendish strain under different conditions will allow natural selection to produce the variation needed to resist infection by pathogenic organisms.

C

Which of the following could best explain the increase in the frequency of the B allele in the population after five years? A The frequency of the BB allele increased because it is the dominant allele. B The frequency of the BB allele increased because squirrels with gray fur exhibited greater fitness. C The frequency of the BB allele increased due to the selective pressures of the environment. D The frequency of the BB allele increased because black squirrels randomly mate with other eastern gray squirrels.

C

Which of the following is an accurate interpretation of the data in Figure 1 ? A R. richardsoni is found significantly more frequently on Species 4 compared to Species 3. B R. colwelli is found significantly more frequently on Species 1 compared to Species 2. C R. richardsoni is found significantly more frequently on Species 3 and Species 4 compared to Species 1 and Species 2. D R. colwelli is found significantly more frequently on Species 3 and Species 4 compared to Species 1 and Species 2.

C

Which of the following observations best helps justify the researcher's claim? A Light-capturing pigment molecules in green plants absorb red, blue, and violet light but reflect green light. B The energy of a photon of light is proportional to its frequency and inversely proportional to its wavelength. C As light energy is converted to chemical energy by metabolic processes, some of the energy is lost as heat. D Captured energy is stored in the molecular bonds of organic molecules, including simple sugars and starch.

C

Which of the following patterns is shown by the data? A Mutant 1 cells are more similar to mutant 3 cells than to wild-type cells. B In wild-type cells, the percent of cells in anaphase is twice the amount of those in telophase C In mutant 3 cells, more time is spent in prophase/prometaphase than in the later stages of mitosis. D The percent of mutant 2 cells in anaphase is higher than that of mutant 1 cells.

C

Which of the following presents a correct interpretation of the changes in chromosome number depicted in Figure 1 ? A DNADNA replication occurs between metaphase and anaphase, doubling the number of chromosomes. Between telophase and cytokinesis, the cell divides in two, with each cell receiving half of the replicated chromosomes. B New chromosomes formed during prophase are doubled during anaphase and are recombined before cytokinesis. C Chromosomes enter metaphase containing two chromatids attached by a centromere. During anaphase, the chromatids are separated, each becoming a chromosome. Cytokinesis distributes the chromosomes into two separate cells. D At anaphase a cell contains two identical copies of each chromosome, but following telophase, one of the copies is broken down into nucleotides.

C

Which of the following provides evidence to best support the researchers' claim? A The organelle has a phospholipid membrane. B The organelle has protein in the membrane. C The organelle has a double membrane. D The organelle has an internal aqueous environment that is similar to the cytosol of the larger cell.

C

Which of the following questions about genetic diversity could most appropriately be answered by analysis of the model in Figure 1 ? A Does crossing-over generate more genetic diversity than the fusion of gametes does? B Does DNADNA methylation prevent independent assortment during metaphase IIII? C How does the independent assortment of the two sets of homologous chromosomes increase genetic diversity? D Do daughter cells that are not genetically identical to parent cells produce viable zygotes?

C

Which of the following statements about glucose, galactose, and fructose is most likely true? A The carbohydrates have the same properties because they have the same number of carbon, hydrogen, and oxygen atoms. B The carbohydrates have the same properties because they each have a single carbon-oxygen double bond. C The carbohydrates have different properties because they have different arrangements of carbon, hydrogen, and oxygen atoms. D The carbohydrates have different properties because they have different numbers of carbon-carbon bonds.

C

Which of the following statements best describes the role of adenylyl cyclase in the epinephrine signaling pathway? A It converts a polymer to its monomer subunits. B It moves substances across the plasma membrane. C It accelerates the production of a second messenger. D It transfers phosphate groups from ATPATP to protein substrates.

C

Which of the following statements best explains the observations represented in Figure 1 ? A There was a net movement of sucrose out of the cell suspended in the sugar solution and a net movement of sucrose into the cell suspended in the distilled water. B There was a net movement of sucrose into the cell suspended in the sugar solution and a net movement of sucrose out of the cell suspended in the distilled water. C There was a net movement of water out of the cell suspended in the sugar solution and a net movement of water into the cell suspended in the distilled water. D There was a net movement of water into the cell suspended in the sugar solution and a net movement of water out of the cell suspended in the distilled water.

C

Which of the following statements best explains the pattern seen on the gel with regard to the size and charge of molecules A and B? A Molecules AA and BB are positively charged, and molecule AA is smaller than molecule BB. B Molecules AA and BB are positively charged, and molecule AA is larger than molecule BB. C Molecules AA and BB are negatively charged, and molecule AA is smaller than molecule BB. D Molecules AA and BB are negatively charged, and molecule AA is larger than molecule BB.

C

Which of the following statements best helps explain the reaction specificity of an enzyme? A The free energy of the reactants is greater than the free energy of the products. B The equilibrium constant of the reaction is much greater than 1. C The shape and charge of the substrates are compatible with the active site of the enzyme. D The concentration of the enzyme inside living cells is greater than the concentration of substrate.

C

Which of the following statements best justifies the inclusion of test tube V as a control in the experiment? A It will provide a measurement of amylase activity at an acidic pHpH. B It will provide a measurement of amylase activity at a basic pHpH. C It will show the color change that occurs in the absence of enzyme activity. D It will show the color change that occurs in the absence of the amylase protein.

C

Which of the following statements best predicts the effect of increasing the permeability of the mitochondrial membranes to large molecules? A ATPATP production will increase because of an increase in the rate at which proteins diffuse out of mitochondria. B ATPATP production will increase because of an increase in the mixing of mitochondrial and cytosolic substances. C ATPATP production will decrease because of an increase in the occurrence of uncontrolled chemical reactions. D ATPATP production will decrease because of an increase in the surface area of the mitochondrial membranes.

C

Which procedure should be done next to gather data needed to meet the scientist's objective? A Incubate samples with the same four ATPATP concentrations at 30°C30°C. B Incubate samples containing 5.0μm/mL5.0μm/mL of ATPATP at four temperatures other than 25°C25°C. C Incubate samples containing 1.0μm/mL1.0μm/mL of ATPATP at four temperatures other than 25°C25°C. D Incubate samples containing 1.0μm/mL1.0μm/mL of ATPATP at 25°C25°C and determine the rate of transport for four other proteins.

C

Which of the following data would support the alternative hypothesis? A Cells with functional aquaporins exhibit low turgor pressure and are hypertonic. B Cells with functional aquaporins exhibit high turgor pressure and are hypotonic. C Cells with mutated aquaporins exhibit an absence of turgor pressure and are completely plasmolyzed. D Cells with mutated aquaporins exhibit moderate turgor pressure and are hypertonic.

D

Based on Figure 1, which of the following best describes how the properties of water at an air-water interface enable an insect to walk on the water's surface? A Covalent bonds between water molecules and the air above provide cohesion, which causes tiny bubbles to form under the feet of the insect. B Ionic bonds between molecules at the surface of the water provide an electric charge, which attracts the feet of the insect, keeping it on the surface. C Polar covalent bonds between molecules at the surface of the water provide adhesion, which supports the weight of the insect. D Hydrogen bonds between molecules at the surface of the water provide surface tension, which allows the water surface to deform but not break under the insect.

D

Of the following, which additional investigation can be used to determine when the cells are in an isotonic solution? A Decreasing the salinity of the environment a little at a time until the ATPATP usage reaches a maximum B Decreasing the salinity of the environment a little at a time until ATPATP usage reaches a minimum C Increasing the salinity of the environment a little at a time until ATPATP usage reaches a maximum D Increasing the salinity of the environment a little at a time until the ATPATP usage reaches a minimum

D

The features of this model provide evidence for which explanation of why all growing strands are synthesized in a 5′ to 3′ direction? A The two strands need to be antiparallel to bond properly. B Thymine and adenine would not bond properly if the strand grew from 3′3′ to 5′5′. C The translation of mRNAmRNA occurs in the 5′5′ to 3′3′ direction; therefore, the growing DNADNA strand must also grow in the 5′5′ to 3′3′ direction. D The phosphate group, attached to the 5′5′ carbon of the dTMPdTMP, forms a covalent bond with the oxygen atom attached to the 3′3′ carbon of the growing strand.

D

The researchers calculate a chi-square value of 4.6 and choose a significance level of p=0.05. Which of the following statements best completes the chi-square goodness-of-fit test? A The null hypothesis can be rejected because the chi-square value is greater than the critical value. B The null hypothesis can be rejected because the chi-square value is less than the critical value. C The null hypothesis cannot be rejected because the chi-square value is greater than the critical value. D The null hypothesis cannot be rejected because the chi-square value is less than the critical value.

D

What is the expected percent change in the DNA content of a typical eukaryotic cell as it progresses through the cell cycle from the start of the G1 phase to the end of the G2 phase? A −100%−100% B −50%−50% C +50%+50% D +100%

D

Which of the following best describes how the amount of DNA in the cell changes during M phase? A The amount of DNADNA doubles as the DNADNA is replicated. B The amount of DNADNA slightly increases as a result of new organelle synthesis. C The amount of DNADNA does not change while the cell grows. D The amount of DNADNA is halved as the cell divides into two daughter cells.

D

Which of the following best explains the cause of the phenotypic variation observed in the butterflies? A Different mutations occurred in the caterpillars that were exposed to different colors of light. B The energy used to grow a larger body results in butterflies with lighter colored wings. C Individual caterpillars evolved adaptations to survive in each of the light conditions they were exposed to. D There was differential gene expression of wing color and body size in response to the colors of light the caterpillars were exposed to.

D

Which of the following best predicts how the amino acid deletion will affect the structure of the CFTR protein? A It will have no observable effect on the structure of the CFTRCFTR protein. B It will affect the primary structure of the CFTRCFTR protein, but the other levels of protein structure will not be affected. C It will affect the secondary and tertiary structures of the CFTRCFTR protein, but the primary structure will not be affected. D It will affect the primary, secondary, and tertiary structures of the CFTRCFTR protein.

D

Which of the following best predicts the outcome of these lizards reproducing for many generations on the islands? A Courtship rituals specific to each island lizard species prevent the lizards from interbreeding. B Speciation results from bottleneck events that happened before the ancestral species reached the islands. C The different species that currently exist are the result of hybridization between lizards from different islands. D The isolation prevents gene flow; thus, the lizards on different islands experience prezygotic isolation.

D

Which of the following best supports the claim that ethylene initiates the signal transduction pathway that leads to ripening of fruit? A Ethylene is a simple gaseous molecule, which makes it easily detected by receptors. B Fruit will ripen in closed containers without exposure to air. C Ethylene synthesis is under both positive and negative feedback regulation. D Loss-of-function mutations in ethylene receptors result in changes to the ripening process.

D

Which of the following conclusions is most clearly supported by the representations of nucleic acid #1 and nucleic acid #2 ? A Nucleic acid #1#1 contains only purines, whereas nucleic acid #2#2 contains only pyrimidines. B Nucleic acid #1#1 contains the sugar ribose, whereas nucleic acid #2#2 contains the sugar deoxyribose. C Nucleic acid #1#1 contains positively charged phosphate groups, whereas nucleic acid #2#2 does not. D Nucleic acid #1#1 contains adenine-thymine base pairs, whereas nucleic acid #2#2 does not.

D

Which of the following conditions will most likely cause a normal body cell to become a cancer cell? A The environment already contains cancer cells. B The environment has an abundance of nutrients. C The environment lacks signals that would otherwise tell the cell to stop dividing. D The environment contains mutagens that induce mutations that affect cell-cycle regulator proteins.

D

Which of the following correctly identifies the dependent variable and the independent variable for the experiment? A The independent variable is the percent of squirrels responding, and the dependent variable is the type of alarm call. B The independent variable is the percent of squirrels responding, and the dependent variable is the type of response. C The independent variable is the group of squirrels, and the dependent variable is the percent of squirrels responding. D The independent variable is the type of alarm, and the dependent variable is the percent of squirrels responding.

D

Which of the following explanations best accounts for this experimental result? A Gel electrophoresis can only be used with DNADNA (not mRNAmRNA), so experimental results are not interpretable. B RNARNA polymerase consistently makes the same errors during transcription of gene LL. C Gene LL is mutated, so RNARNA polymerase does not always transcribe the correct sequence. D Pre-mRNAmRNA of gene LL is subject to alternative splicing, so three mRNAmRNA sequences are possible.

D

Which of the following functional differences between the rough and smooth endoplasmic reticulum (ER) is explained by the structural differences between them? A Rough ERER breaks down toxic substances, and smooth ERER only transports them out of the cell. B Rough ERER can synthesize and package lipids for export, and smooth ERER cannot. C Rough ERER can produce ATPATP, and smooth ERER cannot. D Rough ERER can synthesize and package proteins for export, and smooth ERER cannot.

D

Which of the following is an accurate description of the process shown in Figure 1 ? A The linking of amino acids with an ionic bond as an initial step in the protein synthesis process B The formation of a more complex carbohydrate with the covalent bonding of two simple sugars C The hydrolysis of amino acids with the breaking of covalent bonds with the release of water D The formation of a covalent peptide bond in a dehydration synthesis reaction

D

Which of the following outcomes will most likely result from a change in the shape of the mitochondrial inner membrane from a highly folded surface to a smooth, flat surface? A Mitochondria will become more efficient because the inner mitochondrial membrane will become more permeable to ions. B Mitochondria will become more efficient because the total volume of the mitochondria will increase. C Mitochondria will become less efficient because the inner mitochondrial membrane will become less permeable to large molecules. D Mitochondria will become less efficient because the surface area of the inner mitochondrial membranes will decrease.

D

Which of the following statements best describes how molecules released by the fish become nutrients for the plants? A The carbon dioxide molecules released by the fish are converted by the bacteria to oxygen atoms, which are used by the plants to make water molecules. B The oxygen molecules released by the fish are converted by the bacteria to ammonia molecules, which are used by the plants to make lipids and fatty acids. C The nitrites released by the fish are converted by the bacteria to carbon dioxide molecules, which are used by the plants to make carbohydrates. D The ammonia molecules released by the fish are converted by the bacteria to nitrates, which are used by the plants to make proteins and nucleic acids.

D

Which of the following statements best predicts the effect of increasing the concentration of substrate (ethyl alcohol), while keeping the concentration of the inhibitor (methyl alcohol) constant? A There will be an increase in formaldehyde because ADHADH activity increases. B Competitive inhibition will be terminated because ethyl alcohol will bind to methyl alcohol and decrease ADHADH activity. C The peptide bonds in the active site of the enzyme will be denatured, inhibiting the enzyme. D Competitive inhibition will decrease because the proportion of the active sites occupied by substrate will increase.

D

Which of the following statements best supports the claim that certain organelles within eukaryotic cells evolved from free-living prokaryotic cells? A The cytoplasm of both eukaryotes and prokaryotes is surrounded by a plasma membrane. B Eukaryotes and prokaryotes both contain ribosomes, but the ribosomes of eukaryotes are more complex in structure than those of prokaryotes. C Eukaryotes exchange segments of internal membranes between the endoplasmic reticulum and Golgi apparatus, but prokaryotes have no such internal membranes. D Some organelles contain their own DNADNA that is more similar to prokaryotic DNADNA in structure and function than to the eukaryotic DNADNA found in the cell's nucleus.

D

Which of the following statements best supports the researcher's claim? A Atmospheric carbon dioxide is produced by the burning of fossil fuels, which are formed from the remains of living organisms such as plants. B Atmospheric carbon dioxide is a byproduct of cellular respiration, which is a metabolic process that occurs in plants and other living organisms. C Atmospheric carbon dioxide typically enters plant leaves through stomata, which plants rely on for regulating gas exchange with the atmosphere. D Atmospheric carbon dioxide is the raw material for photosynthesis, which plants rely on for producing sugars and other organic compounds.

D

Which of the following statements is most consistent with the data in Figure 1 ? A Armadillos tend to be more metabolically active than either gerbils or snakes are. B Armadillos cannot survive at environmental temperatures over 30°C30°C. C Snakes are found in terrestrial rather than aquatic environments. D Snakes display behaviors that allow them to absorb or radiate heat as required.

D

Which of the following states a valid null hypothesis about the future distribution of APOE alleles in future generations in the United States? A The APOE-ε2APOE-ε2 allele was the result of chance mutations so it is not possible to predict how its frequency will change in the future. B As high cholesterol diets become more common in the United States, individuals with the APOE-ε2APOE-ε2 allele will have a better survival rate from heart disease than those without the allele, so the allele will increase in frequency. C The low frequency of the APOE-ε2APOE-ε2 allele indicates it is probably a recessive allele, so it will become less frequent as the dominant allele becomes more frequent. D The variant protects an individual from a condition that is only common among humans beyond reproductive age, so the frequency of the allele will likely not change much in the future because it is not influenced by natural selection.

D

Which scientific claim is most consistent with these findings? A DNADNA methylation inhibits transcription of gene RR. B Histone modifications of genes are usually not reversible. C Histone methylation condenses the chromatin at gene RR so transcription factors cannot bind to DNADNA. D Histone methylation opens up chromatin at gene RR so transcription factors can bind to DNADNA more easily.

D

Which statement correctly indicates the cell that is able to more efficiently exchange materials with the external environment and provides a correct explanation? A The egg cell, because it has the smallest surface-to-volume ratio. B The egg cell, because it has the largest surface-to-volume ratio. C The bacterial cell, because it has the smallest surface-to-volume ratio. D The bacterial cell, because it has the largest surface-to-volume ratio.

D

Which statement is the most accurate description of the reaction shown in Figure 1? A It represents monomers linked by dehydration synthesis. B It represents a polypeptide chain that folds to form the tertiary structure. C It represents a polypeptide chain that is denatured into the primary structure. D It represents a polypeptide chain that is broken down through a hydrolysis reaction.

D