Meiosis

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.

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.

Review Questions

• What are the key differences between meiosis I and meiosis II?
• How does crossing over during prophase I contribute to genetic diversity?
• Why is meiosis important for sexual reproduction?

Related terms

Mitosis:

A type of cell division that results in two genetically identical diploid daughter cells.

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

Haploid:

A cell containing a single set of unpaired chromosomes, typically found in gametes.