gametas

Gametas, or gametes, are haploid reproductive cells that participate in sexual reproduction. They arise by gametogenesis in the gonads and fuse during fertilization to produce a diploid zygote, the first cell of a new individual. The haploid state allows for the restoration of diploidy when two gametes combine, contributing to genetic diversity in offspring.

In animals, the two main types are male gametes and female gametes. The male gamete is typically a sperm, which is usually small and motile, designed to reach and fertilize the female gamete. The female gamete is the ovum or egg, which is generally larger and nutrient-rich to support early development. In plants, fungi, and some algae, similar concepts apply, with pollen or other male gametophyte structures delivering male gametes to female gametes within the same or different individuals.

Gametogenesis encompasses the development of gametes through meiosis, followed by cellular development in the respective gonads. Spermatogenesis in males produces a large number of sperm continuously, whereas oogenesis in females typically yields a smaller number of ova, often with supporting polar bodies that are usually discarded.

Fertilization is the union of a male and a female gamete, restoring the diploid chromosome number and initiating embryonic development. This process introduces genetic variation through mechanisms such as recombination and the random combination of paternal and maternal genomes. Variation among gametes, the timing of fertilization, and environmental factors all influence reproductive strategies across species.