Gametogenesis

Gametogenesis is the production of haploid gametes from precursor cells. In plants, animals, and some algae, two morphologically distinct types of gametes are produced via distinct differentiation programs. In animals, gametes develop from a dedicated tissue, the germline, that forms early in embryonic development, and the haploid cells produced by meiosis directly undergo gametogenesis to form gametes. By contrast, plants, fungi, and some protists do not produce a dedicated germline. Rather, diploid somatic cells undergo meiosis, often in specialized structures called sporangia, to produce haploid cells that subsequently divide to produce a haploid gametophyte generation. Eventually, some of these haploid cells, often in response to an environmental stimulus, develop into gametes.