Meiosis I

Definition

Meiosis I is the first division phase in meiosis where homologous chromosomes are separated into two new cells. It reduces the chromosome number by half, resulting in haploid cells.

5 Must Know Facts For Your Next Test

1. Meiosis I includes Prophase I, Metaphase I, Anaphase I, and Telophase I.
2. During Prophase I, homologous chromosomes undergo synapsis and crossing over occurs.
3. In Metaphase I, homologous chromosomes line up along the metaphase plate.
4. Anaphase I involves the separation of homologous chromosomes to opposite poles of the cell.
5. Telophase I results in two haploid cells, each with half the number of chromosomes as the original cell.

Review Questions

• What significant event occurs during Prophase I that increases genetic diversity?
• How do chromosomes align during Metaphase I?
• What is the outcome of Telophase I in terms of chromosome number?

Related terms

Synapsis: The pairing of homologous chromosomes during Prophase I of meiosis.

Crossing Over: The exchange of genetic material between homologous chromosomes during Prophase I.

Haploid Cells: Cells that contain one set of chromosomes (n), produced at the end of Meiosis I and II.