How is meiosis defined?

Meiosis is specifically defined as a type of cell division that reduces the chromosome number by half. This process is crucial for sexual reproduction because it produces gametes—sperm and eggs—in organisms. During meiosis, a diploid cell undergoes two rounds of division to form four genetically diverse haploid cells, each containing half the original number of chromosomes. This reduction in chromosome number ensures that when fertilization occurs, the resulting zygote has the correct diploid chromosome number, maintaining genetic stability across generations.

This biological mechanism is integral to ensuring genetic diversity through processes such as crossing over and independent assortment during meiosis, which contribute to variations seen in the offspring. In contrast, other types of cell division, such as mitosis, focus on growth, repair, and the maintenance of chromosome numbers rather than reducing them.