What is the primary purpose of meiosis?

The primary purpose of meiosis is to reduce diploid cells to four haploid gametes. Meiosis is a specialized form of cell division that occurs in sexually reproducing organisms. This process is essential for sexual reproduction because it ensures that gametes (sperm and egg cells) contain half the number of chromosomes of the original diploid cell.

During meiosis, a single diploid cell undergoes two sequential divisions: meiosis I and meiosis II. In meiosis I, homologous chromosomes are separated, resulting in two haploid cells. Then, in meiosis II, the sister chromatids of each chromosome are separated, leading to a total of four haploid gametes. This reduction in chromosome number is crucial because, when fertilization occurs, the gametes combine to restore the diploid chromosome number in the zygote, maintaining genetic stability across generations.

This process also contributes to genetic diversity through mechanisms such as crossing over and independent assortment, which shuffle genes between chromosomes. Therefore, the reduction of diploid cells to haploid gametes is fundamental to sexual reproduction and the continuation of species.