AP Biology Final Exam 2022

a small protein is composed of 110 amino acids linked together in a chain. as shown in figure 1 the first and last five amino acids in the chain are hydrophobic (have nonpolar and uncharged R-groups), whereas the remaining 100 amino acids are hydrophilic (have charged or polar R- groups). the nature of the R- group determines if the amino acid is hydrophobic or hydrophilic. a mutation results in the production of a version of the small protein that is only 105 amino acids long, as shown in figure 2. five of the hydrophobic amino acids are missing from one end of the change. which of the following best depicts the tertiary structures of the two proteins in water?

(the picture that looks like hair-ties clumped together as two balls)

Water in a pond contaminated with the weed killer atrazine is suspected of inhibiting metamorphosis in northern leopard frogs. A team of scientists collected fertilized northern leopard frog eggs from a different pond that is not contaminated. Which of the following is the best experimental design to determine whether atrazine is responsible for inhibiting metamorphosis in northern leopard frogs? A Place half of the fertilized eggs in a pool of water with the same concentration of atrazine as the contaminated pond and place the other half of the fertilized eggs in a pool of water that has no atrazine. Monitor the development of the embryos through metamorphosis into adulthood. B) Place all of the fertilized eggs in a pool of pond water with the same concentration of atrazine as the contaminated pond and compare the number of frogs that reach metamorphosis to those that reach adulthood in the contaminated pond C. Allow all fertilized eggs to develop into adults. Expose one-third of the frogs to one-half of the concentration of atrazine in the contaminated pond and expose another one-third of the frogs to the same concentration of atrazine as the contaminated pond. Leave the last one-third of the frogs in water with no atrazine and note any adverse changes in the physical condition of the atrazine-treated frogs in three months D) Divide the fertilized eggs into three groups and expose each group to a different concentration of atrazine. Release the eggs back into the contaminated pond and check for metamorphosis after three months.

A Place half of the fertilized eggs in a pool of water with the same concentration of atrazine as the contaminated pond and place the other half of the fertilized eggs in a pool of water that has no atrazine. Monitor the development of the embryos through metamorphosis into adulthood.

question 50 Which of the following best explains why there is no growth on plate 11? A. The initial E. coli culture was not ampicillin-resistant. B. The transformation procedure killed the bacteria C. Nutrient agar inhibits E. col growth. D. The bacteria on the plate were transformed.

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

In dogs, one pair of alleles determines coat color (dark or albino). Another pair of alleles determines hair length (short and long). Thus, each gamete will contain one of the coat-color alleles, C or c, and one of the hair length alleles, B or b. In repeated crosses of a specific dark, short haired dog with an albino, long-haired dog, all of the offspring were dark with short hair, as shown in cross 1. However, in subsequent crosses of another dark, short-haired dog with a dark, long-haired dog, the ratios shown in cross 2 below were obtained. In cross 2, the genotype of the dark, short-haired parent is A- CcBb B- ccbb C- CCBB D- CCbb

A- CcBb

In dogs, one pair of alleles determines coat color (dark or albino). Another pair of alleles determines hair length (short and long). Thus, each gamete will contain one of the coat-color alleles, A or a, and one of the hair length alleles, B or b. In repeated crosses of a specific dark, short haired dog with an albino, long-haired dog, all of the offspring were dark with short hair, as shown in cross 1. However, in subsequent crosses of another dark, short-haired dog with a dark, long-haired dog, the ratios shown in cross 2 below were obtained. Which of the following correctly describes the relationship of the dark-coat-color allele to the albino condition? A- It is dominant B- It is recessive C- It is codominant D- It is a polygenic inheritance pattern

A- It is dominant

Which of the following best describes the role of mitosis in the cell cycle? A- distributed replicated chromosomes to daughter nuclei B- dividing the cytoplasm to form four gametes C- producing organelles and replicating chromosomes D- exchanging genetic material between homologous chromosomes

A- distributed replicated chromosomes to daughter nuclei

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 DNA methylation observed? B- without crossing over, with gametes be liable and be able to produce zygotes? C- does DNA methylation result in shorter chromosomes? D- is the species of fungus a diploid organism?

A- is the level of genetic variation in the gametes related to the amount of DNA methylation observed?

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

Two nutrient solutions are maintained at the same pH. Actively respiring mitochondria are isolated and placed into each of the two solutions. Oxygen gas is bubbled into one solution. The other solution is depleted of available oxygen. Which of the following best explains why ATP production is greater in the tube with oxygen than in the tube without oxygen? A- the rate of proton pumping across the inner mitochondria membrane is lower in the sample without oxygen. B- electron transport is reduced in the absence of a plasma membrane. C- in the absence of oxygen, oxidative phosphorylation produces more ATP than does fermentation. D- in the presence of oxygen, glycolysis produces more ATP than in the absence of oxygen

A- the rate of proton pumping across the inner mitochondria membrane is lower in the sample without oxygen.

Directions: Each set of lettered choices below refers to the numbered words or statements immediately folloving it. Select the one lettered choice that best fits each word or statement. A choice may be used once, more than once, or not at all in each set. The figure below represents a food web in a particular ecosystem. Each letter represents a species. The arrows indicate the direction of energy flow A photosynthetic organism would be represented by which species? A. A B. B C. C D. D E. E

A. A

The validity of the cladogram is best supported by molecular evidence for which of the following changes in the amino acid composition of the beta-heroglobin protein during the evolution of these species? A. Arginine to leucine at position X on the cladogram B. Arginine to leucine at position Y on the cladogram C. Leucine to arginine at position W on the cladogram D. Leucine to arginine at position Z on the cladogram

A. Arginine to leucine at position X on the cladogram

A scientist is attempting to provide support for the hypothesis that RNA was the first genetic material. Which of the following would be a workable alternate hypothesis? A. RNA, like DNA, is a carrier of genetic information and contains the nitrogen bases adenine, guanine, and cytosine. B. RNA can be observed to self-replicate without the assistance of proteins, while DNA always requires protein-based enzymes to replicate. C. RNA exists in both single-stranded and double-stranded configurations; however, it is less stable compared with DNA D. Transfer RNA and ribosomal RNA are products of transcription, but they are not translated as is mRNA.

A. RNA, like DNA, is a carrier of genetic information and contains the nitrogen bases adenine, guanine, and cytosine.

Fur color is a genetically controlled trait in mice. A population of a species of mouse that typically lives in habitats with light-colored soil was studied for several generations. The background color of the habitat of this population became darker after the second generation due to human activity. A researcher sampled approximately 120 mice in each generation and recorded the fur color phenotypes as shown in Figure 1. 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. The null hypothesis is rejected because the change to a darker background color led to an increase in the dark-colored fur phenotype.

In the year 2000, specimens of Caulerpa taxifolia,a green alga used in tropical aquariums, were found off the coast of California, Native to the Indian Ocean, o taxifolia is known for aggressive growth and an ability to compete with seagrasses. It is currently on an international list of invasive species. Which of the following best predicts the consequences of the introduction of C taxi/folia to the California coast? A. Without natural herbivores or competitors, C. taxifolla will grow rapidly and crowd out native species of producers B. taxifolia will have a hard time establishing itself because it will have to compete against native species of seagrasses, which are better adapted to the environment C. taxifolia will grow rapidly, leading to an increase in the diversity of producers. D. Because it is not in the Indian Ocean, its natural environment, C tax/folia will not be able to grow efficiently.

A. Without natural herbivores or competitors, C. taxifolla will grow rapidly and crowd out native species of producers

the model that represents a process occurring in a cell of a particular organism is shown in Figure 1. [ATGATCTCGTAA AUGAUCU TACTAGAGCATT] Figure 1_ Process occurring in a cell Which of the following correctly explains the process shown in Figure 1 ? A. DNA 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 RNA is being produced from a DNA template strand C. The translation is occurring because the two strands have separated and a new strand is being produced. D) Alternative splicing of mRNA is occurring because the mRNA strand is being synthesized from only one strand of DNA

B) Initiation of transcription is occurring because a strand of RNA is being produced from a DNA template strand

A researcher claims that the different metabolic pathways allow bacteria to use different molecules as sources of matter and energy. Which of the following statements best helps justify the researcher's claim by providing a relevant example? A- Rhizobia bacteria from 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- E.coli bacteria reproduce in liquid media containing either glucose or galactose

The model shown in the figure represents the role of two hormones, calcitonin and parathyroid hormones (PTH), in maintaining normal blood calcium levels in humans. If a dietary change results in an increase in blood calcium concentration above normal levels, which of the following is the most likely effect on calcium homeostasis? A- calcitonin levels will decline, thus stimulating the release of PTH B- calcitonin levels will rise, thus promoting the deposit of calcium into bones C- PTH levels will decline, thus stimulating the loss of calcium from bones D- PTH levels will increase, thus preventing the release of calcitonin

B- calcitonin levels will rise, thus promoting the deposit of calcium into bones

The carbon 'that makes up organic molecules in plants is derived directly from A- combustion of fuels B- carbon fixed in photosynthesis C- carbon dioxide produced in respiration D- carbon in the lithosphere E- coal/mines

B- carbon fixed in photosynthesis

The epinephrine signaling pathway plays a role in regulating glucose homeostasis in muscle cells. the signaling pathway is activated by the binding of epinephrine to the beta-2 adrenergic receptor. A simplified model of the epinephrine signaling pathway is represented in Figure 1. 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- in involves enzymes activating other enzymes

The enzyme peroxidase is found in many organisms. It catalyzes the breakdown of hydrogen peroxide into water and oxygen gas. The rate of peroxidase activity at different pH values was assessed by students in the lab. The students' results as shown in graph 1. If the experiment is repeated at pH 11, the observed activity level of the enzyme will most likely be A- the same as the level at pH 7 B- lower than the level at pH 9 C- greater than the level at pH 9 D- between the levels observed at pH 5 and pH 7

B- lower than the level at pH 9

During respiration, most ATP is formed as a direct result of the net movement of A- potassium against a concentration gradient B- protons down a concentration gradient C- electrons against a concentration gradient D- electrons through a channel E- sodium ions into the cell

B- protons down a concentration gradient

Glucocorticoids are steroid hormones that control cellular responses through several different signaling pathways. One of the signaling pathways involves the glucocorticoid receptor, an intracellular protein that is activated by binding to a glucocorticoid molecule. A simplified model of the glucocorticoid receptor signaling pathway is represented in Figure 1. Which of the following statements best predicts the effect of a mutation that results in a loss of the glucocorticoid receptor 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- the glucocorticoid receptor will remain associated with the accessory proteins

Which of the following statements best describes how a growth factor stimulates cell division from outside a cell? A- the growth factor binds to the other cells in the same area and holds them together to form a large, multicellular structure B- the growth factor binds to receptors on the cell surface, initiating a signal transduction pathway that activates specific target genes. C- the growth factor binds to sugar molecules in the extracellular fluid and provides them to the cell a source of energy D- the growth factor binds to phospholipids in the plasma membrane, creating a channel through which substances enter the cell

B- the growth factor binds to receptors on the cell surface, initiating a signal transduction pathway that activates specific target genes.

The model below shows the structure of a portion of a plasma membrane in an animal cell. 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 attracted 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- the hydrophilic phosphate groups of the phospholipid molecules are attracted to the aqueous internal and external environments.

Organelles such as mitochondria and the endoplasmic reticulum have membranes that compartmentalize reactions and other metabolic processes. To function properly, the organelles must move substances across their membranes. 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- they have highly folded membranes

The figure below illustrates a eukaryotic cell. Which of the following best describes how the three structures indicated by the arrows work together? A- to synthesize lipids and modify toxic substances in order to render them harmless B- to synthesize and isolate proteins for secretion or for use in the cell C- to catabolize nutrients and produce ATP for intracellular energy storage D- to synthesize all ribosomal proteins

B- to synthesize and isolate proteins for secretion or for use in the cell

In humans, red-green color blindness is a sex-linked recessive trait. If a man and a woman produce a color-blind son, which of the following must be true? A. The father is color-blind. B. Both parents carry the allele for color blindness. C. Neither parent carries the allele for color blindness D. The father carries the allele for color blindness E. The mother carries the allele for color blindness

B. Both parents carry the allele for color blindness.

The wing of a bat, the flipper of a whale, and the forelimb of a horse appear very different, yet detailed studies reveal the presence of the same basic bone patter. These structures are examples of A. analogous structures B. homologous structure C. vestigial structures D. balanced polymorphism E. convergent evolution

B. Homologous structure

Researchers studied the diversity of macroscopic invertebrates in different areas of watershed ecosystems They collected samples from 58 sites along 11 streams in the same geographical area Their data were classified by stream type and can be found in Figure 1. The stream-type classifications range from the perennial stream type, which always has water, to the intermittent stream type, which is dry for more than nine months during the year Figure 1 Diversity of macroscopic invertebrates in different stream types. Error bars represent a 95% confidence interval two Standard Errors from the mean) 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. Intermittent streams only

Question 40 A model of a process involving nucleic acids is shown in Figure 1 Which of the following best explains what process is represented in Figure 1? A. New DNA strands are being synthesized in the 3 to 5 'direction from their DIN A templates. B. New DNA strands are being synthesized in the 5 'to 3' direction from their DNA templates. C. A new RNA strand is being synthesized in the 3'to 5 'end from its DNA template D. Two new RNA strands are being synthesized in both directions from their DNA templates.

B. New DNA strands are being synthesized in the 5 'to 3' direction from their DNA templates.

which of the following statements best explains the structure and importance of plasmids to prokaryotes? A. Plasmids are circular , single-stranded RNA molecules that transfer information from the prokaryotic chromosome to the ribosomes during protein synthesis. B. Plasmids are circular, double-stranded DNA molecules that provide genes that may aid in survival of the prokaryotic cell. C. Plasmids are single-stranded DNA molecules, which are replicated from the prokaryotic chromosome, that prevent viral reproduction within the prokaryotic cell. D. Plasmids are double-stranded RNA molecules that are transmitted by conjugation that enable other prokaryotic cells to acquire useful genes.

B. Plasmids are circular, double-stranded DNA molecules that provide genes that may aid in survival of the prokaryotic cell.

Beaked whales feed at various depths, but they defecate at the ocean's surface. Nitrogen-rich whale 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? A. There would be a reduction in surface nitrogen concentration, which would cause an algal bloom B. The surface fish populations would decline due to reduced populations of algae. C. The remaining whales would accumulate mutations at a faster rate. D. The remaining whales would be forced to forage in the deepest parts of the ocean

B. The surface fish populations would decline due to reduced populations of algae.

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- the shape and charge of the substrates are compatible with the active site of the enzyme

n a certain flock of sheep, 4 percent of the population has black wool and 96 percent has white wool. Assume that the population is in Hardy-Weinberg equilibrium What percentage of the population is homozygous for white wool? A. 20% B. 40% C. 64% D. 80% E. 96%

C. 64%

Students analyzed several photosynthetic eukaryotic organisms in the laboratory to determine their phylogenetic relationships The organisms were Spirogyra (a green alga), a moss, a spruce tree, and an apple tree. Table 1 compares several characteristics in the organisms (+ indicates the trait is present, - indicates the trait is absent). 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. Cell wall composed of cellulose

In a transformation experiment, a sample of E. colbacteria was mixed with a plasmid containing the gene for resistance to the antibiotic ampicillin (amp*). The plasmid was not added to a second sample, Samples were plated on nutrient agar plates, some of which were supplemented with the antibiotic ampicillin. The results of E. co growth are summarized below. The shaded area represents extensive growth of bacteria, dots represent individual colonies of bacteria. Plates that have only ampicillin-resistant bacteria growing include which of the following? A. 1 only B. Ill only C. IV only D. 1 and il

C. IV only

question 51 Samples of DNA were isolated from four different individuals and each sample was digested by the same restriction enzymes. Gel electrophoresis was used to separate the resulting DNA fragments and the results are shown above. These data best support which of the following hypotheses? A. Individual 1 is the offspring of 2 and 3. B. Individual 1 is the offspring of 3 and 4. C. Individual 2 is the offspring of 1 and 3. D. Individual 2 is the offspring of 1 and 4. E. Individual 3 is the offspring of 1 and 4.

C. Individual 2 is the offspring of 1 and 3

The bird, Parus major, is commonly found in man-made habitats. During the summer these birds primarily feed on insects, and in the winter, when insects are scarce, they forage in gardens and bird feeders for seeds, nuts, and berries, Recently, climate change has led to a decrease in food available from gardens, and scientists have observed that the average beak length of the birds has increased. 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. Longer beaks allow the birds to better access seeds in bird feeder

In eastern gray squirrels, Sciurus carolinensis, the allele for black fur (B) is dominant to the allele for gray fur (b). In a particular population of gray squirrels, 64% have black fur and 36% have gray fur. A researcher calculated the allelic frequencies to be B = 0.4 and b = 0,6. Five years later, the researcher returned to the location and determined the allelic frequencies within the squirrel population to be B = 0,6 and b = 0.4. 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 B allele increased because it is the dominant allele. B. The frequency of the B allele increased because squirrels with gray fur exhibited greater fitness. C. The frequency of the B allele increased due to the selective pressures of the environment. D. The frequency of the B allele increased because black squirrels randomly mate with other eastern gray squirrels.

C. The frequency of the B allele increased due to the selective pressures of the environment.

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? A. The molecules essential to life today did not exist at the time Earth was first formed. B. The molecules essential to life today could not have been carried to the primordial Earth by a comet or meteorite C. The molecules essential to life today could have formed under early Earth conditions. D. The molecules essential to life today were initially self-replicating proteins that were synthesized approximately four billion years ago

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

Question 59 All of the following are examples of prezygotic genetic isolating mechanisms EXCEPT A. Male fireflies of different species have differing flash patterns. B. Three closely related orchid species flower on different days. C. The progeny of a cross between two different lizard species fail to develop properly D. One species of snake lives in water and another is terrestrial. E. Peeper frogs mate in Apni, and tree frogs mate in June.

C. The progeny of a cross between two different lizard species fail to develop properly

In the Florida Everglades, Burmese pythons are an invasive species. They were introduced into southern Florida in 1992. These pythons feed on many of the native Florida species, establishing the pythons as the top predator in the environment. By the year 2000, their population had increased dramatically. Figures 1 and 2 display data collected by ecologists studying the results of the Burmese python invasion. Figure 1 shows counts of animals collected from nighttime road surveys in southem Florida, which are used to estimate population size Figure 2 shows data collected from mosquitoes captured from the wild. DNA sequencing was used to identify the species of blood that the mosquitoes had in their stomachs, identifying various hosts used by the mosquitoes In 1996, the native Culex cedecel mosquitoes in southern Florida preferentially took blood meals from white-tailed deer and raccoons. It was predicted that changes in host population size would alter these hcht preferences. Additionally, it is known that cotton rats are often infected by the Everglades virus, which normally exists in animals, but is capable of infecting humans. Ecologists predict that increased feeding on cotton rats by C. cedece/ may significantly increase the tendency of this virus to infect humans. Which of the following populations have significantly decreased in size between 1996 and 2011? A. White-tailed deer only B. Cotton rats and rabbits only C. White-tailed deer and raccoons only D. White-tailed deer, raccoons, and cotton rats

C. White-tailed deer and raccoons only

CFTR protein is made up of 1,480 amino acids linked together in a chain. Some humans produce a version of the CFTR protein in which phenylalanine (an amino acid) has been deleted from position 508 of amino acid chain . 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 CFTR protein. B- It will affect the primary structure of the CFTR protein, but the other levels of protein structure will not be affected. C- It will affect the secondary and tertiary structures of the CFTR protein, but the primary structure will not be affected. D- It will affect the primary, secondary, and tertiary structures of the CFTR protein.

D- It will affect the primary, secondary, and tertiary structures of the CFTR protein.

A researcher claims that increased atmospheric carbon dioxide levels cause increased growth rates in plants. 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- atmospheric carbon dioxide is the raw material for photosynthesis, which plants rely on for producing sugars and other organic compounds

Both mitosis and meiosis being with a parent cell that is diploid. Which of the following best describes how mitosis and meiosis result in daughter numbers of chromosomes? A- in mitosis, the chromosomes consist of a single chromatid, which is passed to two haploid daughter cells. In meiosis, the chromosomes consist of two chromatids during the first round of division and one chromatid during the second round of division, resulting in two haploid daughter cells. B- In mitosis, synapsis of homologous chromosomes results in four haploid daughter cells after one division. In meiosis, synapsis of homologous chromosomes occurs during the second division and results in four diploid daughter cells C- mitosis produces one identical daughter cell after one round of division. meiosis has two rounds of division and doubles the number of chromosome in the second round of division, producing four diploid cells. D- mitosis produces two identical diploid daughter cells after one round of division. Meiosis produces four haploid daughter cells after two rounds of division.

D- mitosis produces two identical diploid daughter cells after one round of division. Meiosis produces four haploid daughter cells after two rounds of division.

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 DNA and that is more similar to prokaryotic DNA in structure and function than to the eukaryotic DNA found in the cell's nucleus.

D- some organelles contain their own DNA and that is more similar to prokaryotic DNA in structure and function than to the eukaryotic DNA found in the cell's nucleus.

Which of the following observations best represents a mutualistic relationship? (A. Some bacteria and fungi obtain their nutrients by enzymatically digesting larger organisms. (B. Chloroplasts in green algae provide sugars for use in cellular metabolism (C. Hermit crabs utilize empty sea snail shells to protect themselves from predators. (D. Flowers produce nectar that bees gather to make honey, and in the process, the bees pollinate the flowers

D. Flowers produce nectar that bees gather to make honey, and in the process, the bees pollinate the flowers

Question 43 IF Step 1 step 2 step 3 DNA-----Pre-mRNA------mRNA-~----Protein Which of the following best describes an event during step 2 in the simplified model above? A. A new RNA molecule is synthesized using a DNA template B. A new polypeptide is synthesized using an RNA template C. Thymine nucleotides in an RNA molecule are replaced with uracil nucleotides D. Noncoding sequences are removed from a newly synthesized RNA molecule.

D. Noncoding sequences are removed from a newly synthesized RNA molecule.

if the normal spermatogenesis is disrupted, the gametes can have different chromosomes than expected. Which of the following is the most likely cause of one of the four gametes having two X chromosomes and one having neither an X nor a Y chromosome? A. Nondisjunction of the chromosomes during meiosis I B. Nondisjunction of both the X and Y chromosomes during meiosis II C. Nondisjunction of the Y chromosome during meiosis II D. Nondisjunction of the X chromosome during meiosis II

D. Nondisjunction of the X chromosome during meiosis II

Question 45 Antibiotics interfere with prokaryotic cell functions. Streptomycin is an antibiotic that affects the small ribosomal subunit in prokaryotes. Specifically, streptomycin interferes with the proper binding of tRNA to mRNA in prokaryotic ribosomes. Which of the following best predicts the most direct effect of exposing prokaryotic cells to streptomycin? ® A. Amino acid synthesis will be inhibited. B. No mRNA will be transcribed from DNA. C. Posttranslational modifications will be prevented. D. Synthesis of polypeptides will be inhibited.

D. Synthesis of polypeptides will be inhibited.

Figure one shows the number of chromosomes observed in an actively diving human cell at each stage of cell division. Which of the following presents a correct interpretation of the changes in chromosome number depicted in Figure 1? A- DNA replication occurs between metaphase and anaphase, doublin the number of chromosomes. Between telephone 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 in two separate cells. D- at anaphase a cell contains two identical copied of each chromosome, but following telophase, one of the copied is broken down into nucleotides.

[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.

A fish population of 250 in a pond has a maximum annual rate of increase of 0 & 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

c. 450 explanation: expected increase in population = 0.8x250=200 expected population size after one year =250+200=450

Lactose digestion in E col begins with its hydrolysis by the enzyme f-galactosidase. The gene encoding p-galactosidase, lacZ, is part of a coordinately regulated operon containing other genes required for lactose utilization. Which of the following figures correctly depicts the interactions at the lac operon when lactose is NOT being utilized? (The legend below defines the shapes of the molecules illustrated in the options.) RNA polymerase Repressor protein Lactose [check photos for diagram]

(the image with just the operator symbol)

Question 67 All of the following are density-dependent factors that limit animal populations EXCEPT A. weather B. predation C. birthrate D. food competition E. mortality

A. weather

Simple diffusion and facilitated diffusion are related in that both.. A- require protein carriers B- depend on a concentration gradient C- occur via concentrations of cytoskeletal elements attached to the membrane proteins D- are endergonic processes and thus require the hydrolysis of ATP E- occur in eukaryotic cells but not in prokaryotic cells

B- depend on a concentration gradient

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

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? A. The surviving organisms will evolve into a new species. B. The reduced population will likely have allelic frequencies that are different from the initial population. C. The population will adapt to deeper waters to avoid future landslides. D. The reduced population will have a greater number of different genes than the initial population.

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

Cell communication is critical for the function of both unicellular and multicellular eukaryotes. Which of the following is likely true of cell signaling? A- cell signaling uses the highest molecular weight molecules found in living cells B- cell signaling has largely been replaced by other cell functions in higher mammals. C- similar cell signaling pathways in diverse eukaryotes are evidence of conserved evolutionary processes. D- cell signaling functions mainly during early developmental stages

C- similar cell signaling pathways in diverse eukaryotes are evidence of conserved evolutionary processes.

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

If a segment of DNA is 5-TAC GAT TAG-3, the RNA, that results from the transcription of this segment will be A.3-TAC GAT TAU-5' B. 3-ATG CTA ATA-5 C. 3-UAC GAU UAG-5 D. 3'-AAC GAU UAA5' E. 3'-AUC CUA AUC-5

C. 3-UAC GAU UAG-5

An African violet grower observes that genetically identical African violet plants growing near the walls of the greenhouse have white flowers, that plants growing farther away from the walls have pale blue flowers, and that plants growing nearest the center of the greenhouse have dark blue flowers. 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. An enzyme responsible for flower color does not fold correctly in cooler temperatures, and the greenhouse is warmest in the center.

The relative location of four genes an a chromosome can be mapped from the following data on crossover frequencies Which of the following represents the relative positions of these four genes on the chromosome? A. ABCD B. ADCB C. CABD D. CBAD E. DBCA

C. CABD

question 47: Based on the universal genetic code, which of the following represents the correct polypeptide that will result from the translation of the mRNA molecule shown, beginning with the first available start codon? A. Asp - Arg - Met - Val - Thr - Lys-Phe - Gly - His B. Met - Arg - Asp - Stop - His - Gly-Phe - Lys - Thr - Val C. Met - Val - Thr-Lys-Phe-Gly-His D. Val - Thr - Lys-Phe- Gly- Hi

C. Met - Val - Thr-Lys-Phe-Gly-His

The pesticide DDT was widely used in the 1940s as a method of insect control. In the late 1950s the first DDT-resistant mosquitoes were discovered, and eventually DDT-resistant mosquitoes were faund globally. When DDT is used now, the development of DDT resistance in mosquito populations occurs in months rather than years. Which of the tollowing best explains the observations concerning DDT resistance in mosquitoes? A. Competition for limited resources causes mosquitoes to migrate to geographical areas that have richer supplies of DDT. B. The proportion of DDT-resistant mosquitoes in a population remains constant due to the metabolic costs of DDT utilization C. Natural selection favors DDT-resistant mosquitoes that are already present in a population when DDT exposure occurs. D. DDT is a chemical signal that delays normal reproductive cycles in many mosquito populations.

C. Natural selection favors DDT-resistant mosquitoes that are already present in a population when DDT exposure occurs.

The manner in which several different ions and molecules move through a cell membrane is shown in the diagram below. For each ion or molecule, the relative concentration on each side of the membrane is indicated. Which of the following accurately describes one of the movements taking place? A- glucose is transported into the cell by active transport B- Na+ is transported into the cell by active transport C- the movement of glucose through the membrane requires ATP hydrolysis D- NA+ transport out of the cell requires ATP hydrolysis

D- NA+ transport out of the cell requires ATP hydrolysis

Question 35 In the pedigree above, circles represent females, squares represent males, and shaded figures represent individuals expressing a specific trait. The expression of this trait is most likely due to which of the following? A. Sex-linked dominant inheritance (B. Sex-linked recessive inheritance C. Autosomal dominant inheritance D. Autosomal recessive inheritance E. A codominant relationship of a single pair of alleles

D. Autosomal recessive inheritance

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? A. Cloning the largest individuals to counteract the effects of aggressive predation B. Reducing the population size by one-fifth to decrease competition for limited resources C. Constructing a dam and irrigation system to control flooding D. Building ponds in the areas of dry land to promote interbreeding between the separated populations

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

The data above represents the results of three different crosses involving the inheritence of a gene that determine whether a certain organism is blue or white.Which of the following best explains the interference of gene ? A. The allele for white is an autosomal dominant allele because a 1:1 phenotype ratio of blue to white among both sexes is observed in cross 3 B. The allele for blue is an autosomal dominant allele because an approximate 3:1 phenotype ratio of blue to white is observed in cross 1 C. The allele for white is an X-linked dominant allele because no white females are produced in cross 1 D. The allele for blue is an X-linked dominant allele because there are no blue male offfspring in cross 2

D. The allele for blue is an X-linked dominant allele because there are no blue male offfspring in cross 2

Cancer cells behave differently than normal body cells. For example, they ignore signals that tell them to stop dividing. 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. The environment contains mutagens that induce mutations that affect cell-cycle regulator proteins.

A gene that influences coat color in domestic cats is located on the X chromosome. A female cat that is heterozygous for the gene (x4X0) has a calico-colored coat., in a genetics experiment, researchers mate a calico-colored fernale cat (X5)X°) with an orange- colored male cat (X'Y) to produce an F, generation. The researchers record observations for the cats in the F, generation and plan to use the data to perform a chi- square goodness-of-fit test for a model of X-tinked inheritance. The data for the chi-square goodness- of -fit test are presented in Table 1. 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-fittest? 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. The null hypothesis cannot be rejected because the chi-square value is less than the critical value

Question 65 Directions: Each set of lettered choices below refers to the numbered words or statements immediately following it. Select the one lettered choice that best fits each word or statement. A choice may be used once, more than once, or not at all in each set. The figure below represents a food web in a particular ecosystem. Each letter represents a species. The arrows indicate the direction of energy flow Members of which species are herbivores? A. A B. B C. C D. D E. E

D.D

Question 46 A tobacco plant can be made to express a gene from fireflies, resulting in the emission of light. Which of the following is the basis for this phenomenon? A. Chloroplasts can be made to produce light if firefly proteins are injected into plant cells. B. Fireflies and tobacco plants share a recent common ancestor. C. Fireflies and tobacco plants are infected by the same kinds of bacteria. D.Transcription and translation are fundamentally similar in both fireflies and tobacco plant

D.Transcription and translation are fundamentally similar in both fireflies and tobacco plant

The following questions refer to an experiment that is set up to determine the relative volume of O2 consumed by germinating and nongerminating (dry) pea seeds of two different temperatures. The change in volume is detected by using a respirometer over a given period of time. The data are given below. Which of the following conclusions is best supported by the data? A- non germinating pea seeds have a higher rate of respiration than germinating pea seeds do. B- light is required for pea seed germination C- in the non germinating pea seeds, oxygen consumption is directly proportional to oxygen concentration D- less carbon dioxide is produced by germination pea seeds at 26 degree Celsius than at 10 degree Celsius E- in pea seeds an increase in temperature results in an increase in oxygen consumption

E- in pea seeds an increase in temperature results in an increase in oxygen consumption

Which of the following is an important difference between light-dependent and light-independent reactions of photosynthesis? A- the light-dependent reactions occur only during the day, the light-independent reactions occur only during the night B- the light-dependent reactions occur in the cytoplasm, the light-independent reactions occur in chloroplasts C- the light-dependent reactions utilize CO2 and H2O, the light-independent reactions produce CO2 and H2O D- the light-dependent reactions depend on the presence of both photosynthesis I and II, the light-independent reactions require only photosynthesis I E- the light-dependent reactions produce ATP and NADPH, the light-independent reactions use energy stored in ATP and NADPH

E- the light-dependent reactions produce ATP and NADPH, the light-independent reactions use energy stored in ATP and NADPH

question 66 Which point on the curve in the diagram above best represents the carrying capacity of the environment for the population shown? A. A B. B C. C D. D E. E

E. E