12. Meiosis

Which statement describes a major difference between meiosis II and mitosis in a diploid animal?

During which of the following stages of meiosis do homologous chromosomes pair up and align along the metaphase plate of the cell?

What separates during Anaphase II?

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

Select True or False for each statement.

Sister chromatids are homologous chromosomes.

Non-sister chromatids are found on two different homologs.

Crossing over occurs between sister chromatids.

A chiasma forms between two of the four molecules of double-stranded DNA on duplicated homologous chromosomes.

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

If you followed a woman's cells through meiosis, at what stage of meiosis would the amount of DNA in one of these cells be equal to the amount of DNA in one of her G1 phase (before DNA replication) kidney cells?

Norway rats have 42 chromosomes in their diploid cells. If such a cell enters meiosis, how many chromosomes and double-helical molecules of DNA will be present in each daughter cell at the end of meiosis II?

a. 21 chromosomes and 21 double-helical DNA molecules

b. 21 chromosomes and 42 double-helical DNA molecules

c. 42 chromosomes and 42 double-helical DNA molecules

d. 42 chromosomes and 84 double-helical DNA molecules

A micrograph of a dividing cell from a mouse showed 19 chromosomes, each consisting of two sister chromatids. During which of the following stages of cell division could such a picture have been taken? (Explain your answer.)

a. Prophase of mitosis

b. Telophase II of meiosis

c. Prophase I of meiosis

d. Prophase II of meiosis