What type of cell division occurs in all sexually reproducing eukaryotes?

Meiosis is the type of cell division that occurs in all sexually reproducing eukaryotes. This process is crucial for the production of gametes—sperm and eggs—where the chromosome number is halved from diploid (2n) to haploid (n). This reduction is essential for maintaining the species' chromosome number across generations; when the gametes fuse during fertilization, the diploid number is restored.

Meiosis consists of two sequential divisions: meiosis I and meiosis II. During meiosis I, homologous chromosomes are separated, while meiosis II resembles a mitotic division where sister chromatids are separated. The genetic variation introduced through crossing over and independent assortment during meiosis enhances genetic diversity in the offspring, which is a key advantage in evolution and adaptation.

In contrast, mitosis is primarily responsible for growth and repair in somatic cells and does not reduce the chromosome number. Binary fission is the method of reproduction in prokaryotes, such as bacteria, and is not applicable to eukaryotic organisms. The term "cell division" is broad and refers generally to the process by which a parent cell divides into daughter cells, encompassing both mitosis and meiosis but not specifying the type relevant