Ap Bio Unit 5: MCQ progress check

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.

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

Separation of chromatids occurs once, and there are two rounds of cell division in meiosis.

The students plan to use a significance level of p=0.01. Which of the following is the most appropriate critical value for the students to use in their chi-square goodness-of-fit test?

11.34

The mean map distance between gene R and gene L is closest to which of the following?

28 map units

The mean number of fruit flies per student that are homozygous recessive for both genes is closest to which of the following?

29

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

Sex chromosomes determine the phenotype of sex in humans. Embryos containing XX chromosomes develop into females, and embryos containing XY chromosomes develop into males. The sex chromosomes separate during meiosis, going to different gamete cells. A woman is heterozygous for the X-linked recessive trait of hemophilia A. Her sex chromosomes can be designated as XHXh. During meiosis the chromosomes separate as shown in Figure 1. Figure 1. Transmission pattern for sex chromosomes of a woman heterozygous for hemophilia A into gametes If the woman and a man with normal clotting function have children, what is the probability of their children exhibiting hemophilia A?

50 percent for sons, 0 percent for daughters

Researchers performed a dihybrid cross with coffee bean 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 Table 1. Which of the following is closest to the calculated chi-square (χ2) value for the data presented in Table 1?

72.01

Huntington's disease has been traced to the number of CAG repeats in the HTT gene, which is located on chromosome 4. The phenotypic influence of individual alleles with different numbers of repeats is shown in Table 1. 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 CAGCAG repeats was inherited by the affected person.

A model of crossing over during gamete formation is shown in Figure 1. Figure 1. Model of crossing over during meiosis Based on Figure 1, which of the following questions could best be addressed?

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

A model showing the cells in anaphase 1 and anaphase 2 of meiosis during a nondisjunction event is shown in Figure 1. Figure 1. Model of a nondisjunction event 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.

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

Homologous pairs of chromosomes are aligned during metaphase II, but individual chromosomes are aligned during metaphase IIII.

A compound that prevents the separation of the homologous chromosomes in anaphase I is being studied. Which of the following questions can be best answered during this study?

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

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.

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.

Which of the following best explains how the sweet pea plants in the parental generation produce F1 offspring with 14 chromosomes?

Meiosis 2 and 3 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.

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. Figure 1. Summary of a genetics experiment using pea plants 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?

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

Based on the data in Figure 1, which of the following is the best prediction of the mode of inheritance of red eyes in Japanese koi?

The allele for red eyes is inherited in an autosomal dominant pattern.

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.

The researchers calculated a chi-square value of 29.25. If there are three degrees of freedom and the significance level is p=0.05, which of the following statements best completes the chi-square test?

The critical value is 7.82, and the null hypothesis can be rejected because the calculated chi-square value is greater than the critical value.

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 follow indicates the mean number per cross of F2 plants producing medium-red grain and correctly explains the distribution of the phenotypes?

The mean number of medium-red phenotypes per cross is 20.8. The distribution of phenotypes suggests that multiple genes are involved in grain color determination.

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?

Several members of a family are found to involuntarily sneeze when exposed to bright lights, such as sunlight. Following analysis of the condition in the family, a doctor predicts that the symptoms have an underlying genetic basis. A pedigree of the family is shown in Figure 1. Figure 1. Pedigree showing family members with and without symptoms For this condition, which of the following modes of inheritance is most consistent with the observations?

autosomal dominant