What is the process of cell division that produces gametes with half the number of chromosomes?

Meiosis is the process of cell division specifically responsible for producing gametes—sperm and egg cells—in sexually reproducing organisms. This process is crucial because it reduces the chromosome number by half, resulting in haploid cells. In humans, for example, meiosis transforms diploid cells, which contain 46 chromosomes, into gametes that contain only 23 chromosomes.

During meiosis, two successive divisions occur: meiosis I and meiosis II. In meiosis I, homologous chromosomes are separated, while meiosis II resembles a mitotic division where sister chromatids are finally separated. The result is four genetically diverse haploid gametes, each carrying half the genetic information required to form a new organism upon fertilization.

The other processes mentioned involve different mechanisms: mitosis is for somatic cell division and retains the diploid chromosome number; binary fission is a form of asexual reproduction in prokaryotes; and apoptosis is a programmed cell death process that does not involve division at all. Understanding these distinctions highlights why meiosis is the correct answer when discussing the creation of gametes with half the number of chromosomes.