In meiosis I, specifically during karyokinesis (the division of the nucleus), the homologous chromosomes separate. This is a critical step in meiosis, as it ensures that each daughter cell receives one chromosome from each pair of homologous chromosomes.
Steps involved in karyokinesis of meiosis I:
- Prophase I: Chromosomes condense and homologous chromosomes pair up through a process known as synapsis. Crossing-over occurs, exchanging genetic material between homologous chromosomes.
- Metaphase I: Homologous chromosome pairs align at the equatorial plate of the cell.
- Anaphase I: The homologous chromosomes are pulled apart by the spindle fibers toward opposite poles of the cell. This is where the separation occurs.
- Telophase I: The separated chromosomes reach the poles, and the cell divides into two daughter cells.
Thus, during meiosis I, it is the homologous chromosomes that separate, not the sister chromatids, which occur in meiosis II.