what are the stages of meiosis

what are the stages of meiosis

1 year ago 45
Nature

Meiosis is a type of cell division that produces sex cells or gametes, such as eggs in females and sperm in males. Meiosis can be divided into two main stages: meiosis I and meiosis II. Both stages follow the same stages as mitosis, which are prophase, metaphase, anaphase, and telophase.

The stages of meiosis I are as follows:

  1. Interphase: The DNA in the cell is copied resulting in two identical full sets of chromosomes.
  2. Prophase I: Chromosomes condense, nuclear membrane dissolves, homologous chromosomes form bivalents, crossing over occurs.
  3. Metaphase I: Spindle fibers from opposing centrosomes connect to bivalents (at centromeres) and align them along the middle of the cell.
  4. Anaphase I: Spindle fibers contract and split the bivalent, homologous chromosomes move to opposite poles of the cell.
  5. Telophase I and cytokinesis: Chromosomes decondense, nuclear membrane may reform, cell divides (cytokinesis) to form two haploid daughter cells.

The stages of meiosis II are as follows:

  1. Prophase II: Chromosomes condense, nuclear membrane dissolves, centrosomes move to opposite poles (perpendicular to before).
  2. Metaphase II: Chromosomes line up in single file along the equator of the cell.
  3. Anaphase II: Sister chromatids are pulled to opposite poles of the equator.
  4. Telophase II and cytokinesis: This stage is the same as telophase I, and the cell divides to form four haploid daughter cells.

It is important to note that meiosis I is a reduction division, which reduces the number of chromosomes from diploid to haploid, while meiosis II is equational, meaning that the number of chromosomes remains the same.

Read Entire Article