Meiosis

What type of cell(s) does meiosis start with?

• Meiosis starts with a diploid cell (2n), typically a germ cell.

What type of cell(s) does meiosis end with?

• Meiosis ends with haploid cells (n), which are gametes (sperm or egg cells).

How many divisions occur in meiosis?

• Meiosis consists of two divisions, called Meiosis I and Meiosis II.

When does crossing over occur?

• Crossing over occurs during Prophase I of Meiosis I.

What happens in crossing over?

• Homologous chromosomes exchange segments of genetic material, leading to genetic recombination.

Why is crossing over important?

• Crossing over increases genetic diversity by creating new combinations of alleles in gametes.

How many times is the DNA copied in meiosis? In which stage?

• DNA is copied once, during the S phase of interphase, before meiosis begins.

What type of cell is made in meiosis?

• Meiosis produces gametes (sperm and egg cells).

If you start with 46 chromosomes, how many chromosomes will the gametes have?

Why do cells undergo meiosis?