AP Biology Test Question Review

Pedigree

B

Cladogram

C

Which of the following correctly explains where DNA replication will begin on the strand oriented 5' to 3', reading from left to right?

DNA replication will be initiated immediately to the left of the RNA, since DNA polymerase requires an RNA primer.

In sweet pea plants, two heterozygous plants for color and pollen shape were crossed and the results were not 9:3:3:1 ratio. Which of the following statements provides the most reasonable prediction to account for the deviation from the expected results?

In sweet pea plants, the gene for flower color and the gene for pollen grain shape are genetically linked.

Based on the information in Table 1, which of the following statements best describes the production of nearly identical AFGPs in these two species of fish?

The fish live in environments with similar selective pressures, and those that produce AFGPs are better able to survive.

Table 1. Effect of Exposing Identical Caterpillars to Specific Colors of Light. Which of the following best explains the cause of the phenotypic variation observed in the butterflies?

There was a differential gene expression of wing color and body size in response to the colors of light the caterpillars were exposed to.

Which of the following statements best explains how a condition of Hardy-Weinberg equilibrium results in a population that exhibits stable allele frequencies?

Without migration or mutation, new alleles cannot be introduced to the population.

CTC to CAC, Which of the following best describes the type of mutation shown in Figure 1 that leads to sickle-cell anemia?

substitution

B changed from 0.4 to 0.6. Which of the following could best explain the increase in the frequency of the B allele in the population after five years?

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

Scientists have observed that otters in the area are experiencing increased mortality because of an increase in harmful algal blooms. Which of the following best describes what happened to the otter population?

the population lost genetic diversity as a result of a bottleneck effect.

A particular triplet of bases in the template strand of DNA is 5' AGT 3'. The corresponding codon for the mRNA transcribed is

3' UCA 5'

Which of the following helps to stabilize mRNA by inhibiting its degradation?

5' cap and poly (A) tail

Which of the following is most likely the cause of the pattern of frequency of trisomy 21 births in the selected maternal age-groups?

At older maternal ages, the incidence of errors in meiosis during egg production increases, which leads to an increase in nondisjunction.

Table 1. Nucleotide composition of sample DNA from selected organisms. Which of the following statements best explains the data set?

Since the %A and %T are approximately the same in each sample, adenine and thymine molecules must pair up in a double-stranded DNA molecule.

In the cross diagrammed above, the expected and observed results are shown. Which of the following best explains the observed results of the cross?

The genes for body color and wing shape are located close to each other on the same chromosome.

The figure above represents tRNA that recognizes and binds a particular amino acid. Which codon on the mRNA strand codes for this amino acid?

UUC

Which of the following questions will best help the genetic counselor to evaluate the risk of a young man developing Huntington's disease and transmitting it to his children?

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

The phenotypic variation in behavior between the two populations can best be described as resulting from

artificial selection

Which of the following statements correctly describes the chromosomes in each daughter cell at the end of meiosis I?

Each daughter cell contains 12 chromosomes, each composed of two chromatids. Each chromosome is one of a pair of homologous chromosomes from the parent cell with the other homologue found in the other daughter cell.

Which of the following questions about genetic diversity could most appropriately be answered by analysis of the model in Figure 1?

How does the independent assortment of the two sets of homologous chromosomes increase genetic diversity?

Which of the following best describes the process responsible for the change in the percent of tuskless female elephants in the Gorongosa National Park population shown in Figure 1?

Human hunting of elephants with tusks between 1977 and 1992.

A model that represents a process occurring in a cell of a particular organism is shown in Figure 1. Which of the following correctly explains the process shown in Figure 1?

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

During prophase I replicated homologous chromosomes pair up and undergo synapsis. What testable question is generated regarding synapsis and genetic variability by Figure 1?

Is the distance between two gene loci related to crossover rate?

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?

Is the level of genetic variation in the gametes related to the amount of DNA methylation observed?

Both mitosis and meiosis begin with a parent cell that is diploid. Which of the following best describes how mitosis and meiosis results in daughter cells with different numbers of chromosomes?

Mitosis produces two identical daughter cells after one round of division. Meiosis produces four haploid daughter cells after two rounds of division.

Which of the following best explains the distribution of lactase persistence in the areas shown in Figure 1?

Mutations conferring lactase persistence likely arose independently in different geographic areas and offered a selective advantage.

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?

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

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?

Synthesis of polypeptides will be inhibited.

A current challenge for doctors involves the bacterial strain Clostridioides difficile, which no longer responds to traditional antibiotic treatments. Which of the following best explains why this particular strain of bacteria is resistant to antibiotic treatment?

The bacteria have high genetic variability and high reproductive rates

FIgure 1 represents part of a process that occurs in eukaryotic cells. These are untranslated regions (UTR) in this sequence. Which of the following best explain the process represented by Figure 1?

The enzyme-regulated processing of pre-RNA into mature mRNA.

Females: 40 red eyes, 13 sepia eyes. Males: 39 red eyes, 11 sepia eyes. Which of the following best describes the likely mode of inheritance for the eye-color gene?

The eye-color gene is likely autosomal because males and females have similar phenotype ratios.

Birds feed off of gardens and bird feeders. Which of the following best explains the directional shift in beak length in these birds?

longer beaks allow the birds to better access seeds in bird feeders.

What amino acid sequence will be generated, based on the following mRNA codon sequence? 5' AUG-UCU-UCG-UUA-UCC-UUG 3'

met-ser-ser-leu-ser-leu

The blue-flowered African violet of unknown ancestry self-pollinated and produced 50 seeds. These seeds germinated and grew into flowering plants. Of these plants, 36 produce blue flowers and 14 produce pink flowers. What is the best explanation for the pink flowered offspring?

pink flower color is a trait recessive to blue flower color.