AP Bio 2014 Practice Test FRQ

8B)Bacteriophages, like other viruses, consist primarily of a protein coat and packaged DNA. Describe the function of ONE critical enzyme in bacterial cells that is necessary for replicating bacteriophage DNA. (1 point maximum)

• DNA polymerase synthesizes new DNA.

4C)Based on the scientist's claim, predict which treatment group will have the smallest amount of accessible nutrients in the soil at the end of the experiment. Justify your prediction in terms of the relative impact of a keystone species in the environment. (2 points maximum

Group 1 -Keystone species have a disproportionate impact on the ecosystem relative to their abundance.

1B) Based on the experimental results, estimate the optimal pH of the enzyme. Explain your estimate by connecting the experimental results to the structure and function of proteins. (3 points maximum)

(1) 8 (2) Highest absorbance amount while others didn't (3)denatures the enzyme and reduces its activity alters the structure of the enzyme's active site and reduces its

2A)Based on a pedigree of a family in which one parent in the first generation has Loeys-Dietz syndrome (type 2B), a researcher claims that the disorder is an autosomal dominant condition. Describe TWO characteristics of the pedigree that would support the researcher's claim. (2 points maximum)

Autosomal-Inherited equally by males and females Dominant- If the trait is not observed in one generation it will not be observed in subsequent generations. There are no unaffected carriers of the allele

4A)Describe ONE common role of both bacteria and fungi in the movement of energy and matter in ecosystems

Both bacteria and fungi recycle nutrients by breaking down organic matter

6A)Describe ONE type of molecular evidence that can be used to determine the genetic relatedness of bacterial strains isolated from naturally occurring populations

DNA/RNA sequence comparison between the two bacterial strains

2D) Propose THREE features of a model to connect the genetic mutation you predicted with the activity of a signaling pathway involving the LDS2B gene product. (3 points maximum

Mutation causes a structural change in polypeptide. • Change in sequence activates signaling (a gain of function). • Change in sequence decreases signaling pathway (a loss of function).

5A)Describe TWO functions of neurotransmitters at the postsynaptic membrane. (2 points maximum)

Neurotransmitters bind to receptor molecules. Neurotransmitters open ion channels.

5B)Based on the information provided above, explain how TTX most likely interferes with the transmission of information across synapses. (2 points maximum)

No action potential in neurons Na+ cannot flow across neuronal membranes

6B)Using the information presented in the graph, describe the relationship between antagonism and genetic relatedness in the communities of Vibrio bacteria sampled for the study. (1 point)

↑ genetic distance ↑ antagonism

7A)Make a claim about the role of the inner mitochondrial membrane in ATP synthesis. 7B)Present ONE piece of experimental evidence that supports the role you proposed in part (a). 7C)Provide reasoning to explain how the evidence you presented in part (b) supports the claim you made in part (a)

IMM is the site for ATP synthesis Presence of ATP synthase in IMM IMM is where ADP undergoes phosphorylation IMM contains ATP synthase complex for making ATP. Protons move through ATP synthase from intermembrane space to matrix and produce ATP

8A)Predict the experimental result that would best support the claim that DNA is the source of heritable information, and provide reasoning to explain how the result supports the claim. (2 points maximum)

Radioactive phosphorus label is found mostly inside infected cells. Radioactive phosphorus labels DNA. Radioactive sulfur primarily labels proteins.

1C)Propose an appropriate control treatment for the experiment, and describe how the control treatment would increase the validity of the results. (2 points maximum)

Reaction with enzyme- proves enzyme is needed Reaction with Denatured enzyme- proves it must be active

2C)One genetic change associated with the disorder results in a methionine-to-valine substitution at amino acid position 425 of the encoded polypeptide, as shown in Figure 1. Using the codon table in Figure 2, predict a DNA point mutation that will result in a methionine-to-valine substitution. (1 point maximum)

T-->C

6C) Provide reasoning to show how the results of the study support the claim that cooperation among Vibrio bacteria can increase the fitness of some individual bacteria living in a natural environment.

By producing antimicrobial substances, the bacteria promote the growth of bacteria that are genetically related.

4B) Describe how analyzing the data from the treatment group sprayed with water only will increase the validity of the experimental results

Describe that the water only treatment is a control that allows any change in the experimental groups to be attributed to the presence or absence of bacteria or fungi.

1D) Genetic engineering can be used to disrupt specific genes in the genome of an organism. Predict how the browning of apple slices would be affected in a strain of apples that was genetically engineered to lack functional copies of the gene encoding polyphenol oxidase. Justify your response. (2 point)

Fruit will not brown- Browning requires a functional enzyme.

3B)Predict the most likely single mutation affecting amino acid 104 in the species and justify how β-hemoglobin can function normally in all four species despite the mutation.

G -->A mutation in second position of the Arg codon of the coding/nontemplate strand If the substitution doesn't cause a major disruption of structure, the function is maintained.