Unit 5 Multiple Choice Questions

Four trials measuring recombination frequency between gene R and gene L were conducted, and the results are shown in Table 1. The mean map distance between gene R and gene L is closest to which of the following?

28 map units

How many degrees of freedom should be used when looking up the critical value for a chi-square analysis of the ratios of phenotypes observed among the F2 offspring versus the expected phenotypic ratio assuming independent assortment?

3

researchers performed a dihybrid cross with coffee beans plants to investigate whether the inheritance of two traits (height and stem circumference) follows Mendel's law of independent assortment. The data for the F2 generation are presented in the table which of the following is closest to the calculated chi square value for the data presented in table 1?

72.01

Which of the following is most likely the immediate cause of the first appearance of Huntington's disease in a person?

An allele with more than 39 CAG repeats was inherited by the affected person.

a model of crossing over during gamete formation is shown in figure one based on the figure which of the following questions could be addressed?

Does synapses of homologous chromosomes in the parent cell contribute to an increase in genetic diversity in the daughter cells?

Which of the following best predicts the effect of the chromosomal segregation error shown in Figure 1?

Half of the resulting gametes will have the correct number of chromosomes, and the other half will have an incorrect number of chromosomes.

The tadpoles of Mexican spadefoot toads are known to exhibit phenotypic plasticity depending on food availability. Tadpole mouthparts can vary significantly, prompting researchers to categorize them as either omnivore-morph or carnivore-morph. Carnivore-morph tadpoles are larger and have mouthparts that are better suited for predation. Remarkably, carnivore-morph tadpoles can change into omnivore-morph tadpoles when the food supply changes. Which of the following best describes an advantage of the phenotypic plasticity displayed by the tadpoles?

It gives the tadpoles increased versatility with respect to diet.

When a mustard plant seedling is transferred to an environment with higher levels of carbon dioxide, the new leaves have a lower stomata-to-surface-area ratio than do the seedling's original leaves. Which of the following best explains how the leaves from the same plant can have different stomatal densities when exposed to an elevated carbon dioxide level?

Leaf growth is promoted through increased photosynthesis, but the genetically regulated rate of stomatal production is not altered, leading to a decrease in stomatal density.

Sweet pea plants have a diploid (2n) chromosome number of 14. Which of the following best explains how the sweet pea plants in the parental generation produce F1 offspring with 14 chromosomes?

Meiosis II and IIII lead to the formation of cells with 7 chromosomes. During meiosis II, homologous chromosomes separate. During meiosis IIII, sister chromatids separate. Two cells combine during fertilization to produce offspring with 14 chromosomes.

Glycolysis is a metabolic pathway that converts glucose into pyruvate and is observed in each of the three domains. The hexokinase family of enzymes is required during glycolysis to phosphorylate six-carbon sugars. Researchers designed a general hexokinase inhibitor that is effective in the neurons of rats. Which of the following best predicts the effect of adding this inhibitor to a culture of plant cells?

Plant cells will be unable to perform glycolysis due to the inhibitor and will die.

In pea plants, purple flower color is dominant to red flower color and long pollen grains are dominant to round pollen grains. Researchers crossed two pure-breeding lines of the pea plants to investigate whether the genes controlling flower color and pollen shape segregate independently. The procedure for the genetics experiment is summarized in Figure 1. Which of the following tables best shows the expected values in the F2 generation for a chi-square goodness-of-fit test for a model of independent assortment?

Purple, long 1199 Purple, round 400 Red, long 400 Red,round 133

In corn plants, purple kernel color is dominant to yellow kernel color, and smooth kernels are dominant to wrinkled kernels. Researchers carried out a genetics experiment to investigate whether the genes controlling kernel color and kernel texture segregate independently. In their experiment, the researchers crossed two corn plants that were each heterozygous for both kernel color and kernel texture. The results of the experiment are presented in Table 1. Using a significance level of p=0.05, which of the following statements best completes a chi-square goodness-of-fit test for a model of independent assortment?

The calculated chi-square value is 3.91, and the critical value is 7.82. The null hypothesis cannot be rejected.

Himalayan rabbits are a breed of rabbits with highly variable fur color. If genetically similar rabbits are raised in environments that have different temperature conditions, the rabbits can have different color patterns. Which of the following statements best explains how the fur color can be different in Himalayan rabbits raised under different temperature conditions?

The environment determines how the genotype is expressed.

Which of the following questions would be most useful to researchers trying to determine the role of meiosis in the F2 phenotypic frequencies?

What is the recombination frequency between the genes for petal shape and pollen shape?

which of the following best explains a distinction between metaphase I and metaphase II?

homologous pairs of chromosomes are aligned during metaphase I but individual chromosomes are aligned during metaphase II

in anaphase I of meiosis, cohesion between the centromeres of sister chromatids is maintained while homologous chromosomes migrate to opposite poles of the cell along the meiotic spindle as represented in figure 1

is there a pattern to the movement of homologous chromosomes in the presence of this compound?

for sexually reproducing diploid parents cells, which of the following statements best explains the production of haploid cells that occurs in meiosis but not in mitosis

separation of chromatids occur once, and there are tow rounds of cell division in meiosis