🦠microbiology review

Meiosis

Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025

Definition

Meiosis is a type of cell division that reduces the chromosome number by half, resulting in four genetically diverse haploid cells. It is crucial for sexual reproduction and genetic diversity in eukaryotic organisms.

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5 Must Know Facts For Your Next Test

  1. Meiosis consists of two successive divisions: meiosis I and meiosis II.
  2. During prophase I, homologous chromosomes undergo synapsis and crossing over, which increases genetic variability.
  3. Meiosis I results in two haploid cells with duplicated chromosomes, while meiosis II resembles mitosis and separates sister chromatids.
  4. The end product of meiosis is four non-identical haploid gametes or spores.
  5. Errors in meiosis can lead to aneuploidy conditions such as Down syndrome.

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