During what phase of meiosis does crossing over occur?

A normal somatic human cell contains 46 chromosomes. During anaphase of meiosis I, prior to reformation of the nuclear envelope, how many chromosomes are present in a human cell?

Suppose X is the amount of DNA in a mature human cell that is not actively replicating. What amount of DNA would be found in a mature cell that has fully completed meiosis?

Which of the following are true of meiosis?

During which of the following stages of meiosis is the ploidy of the cell equal to n (haploid)?

I. Telophase I, after nuclear envelopes reform

II. Metaphase II, while chromosomes are lined up on the equatorial plate

III. Anaphase II, immediately after separation of sister chromatids

IV. Metaphase I, while chromosomes are lined up on the equatorial plate

Which event takes place in meiosis, but not in mitosis?