What is the process called that results in the formation of gametes with half the normal number of chromosomes?

The formation of gametes with half the normal number of chromosomes is known as meiosis. This specialized type of cell division reduces the chromosome number by half through two sequential rounds of division, ensuring that when gametes unite during fertilization, the resulting offspring have the correct diploid number of chromosomes.

Meiosis consists of one round of chromosome duplication followed by two rounds of division—meiosis I and meiosis II. During meiosis I, homologous chromosomes are separated, which reduces the chromosome number from diploid (2n) to haploid (n). Then, meiosis II separates the sister chromatids without further replication, finalizing the production of four haploid gametes from a single diploid cell.

This process is critical for sexual reproduction, allowing for genetic diversity through the recombination of genetic material. By contrast, other processes such as mitosis result in identical diploid cells, fertilization combines gametes to restore the diploid number, and binary fission is a method of asexual reproduction in single-celled organisms.