Chapter 13, Problem 4
If the DNA content of a diploid cell in the G1 phase of the cell cycle is x, then the DNA content of the same cell at metaphase of meiosis I will be a. 0.25x. b. 0.5x. c. x. d. 2x.
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A human cell containing 22 autosomes and a Y chromosome is a. a sperm. b. an egg. c. a zygote. d. a somatic cell of a male.
The two homologs of a pair move toward opposite poles of dividing cell during a. mitosis. b. meiosis I. c. meiosis II. d. fertilization.
Meiosis II is similar to mitosis in that a. sister chromatids separate during anaphase. b. DNA replicates before the division. c. the daughter cells are diploid. d. homologous chromosomes synapse.
If we continue to follow the cell lineage from question 4, then the DNA content of a single cell at metaphase of meiosis II will be a. 0.25x. b. 0.5x. c. x. d. 2x.
DRAW IT The diagram shows a cell in meiosis. a. Label the appropriate structures with these terms: chromosome (label as duplicated or unduplicated), centromere, kinetochore, sister chromatids, nonsister chromatids, homologous pair (use a bracket when labeling), homolog (label each one), chiasma, sister chromatid cohesion, and gene loci, labeling the alleles of the F and H genes.
Assume that genes A and B are on the same chromosome and are 50 map units apart. An animal heterozygous at both loci is crossed with one that is homozygous recessive at both loci. What percentage of the offspring will show recombinant phenotypes resulting from crossovers? Without knowing these genes are on the same chromosome, how would you interpret the results of this cross?