meiotikus

Meiotikus is the term used to describe processes related to meiosis, the specialized cell division that reduces the chromosome number by half to produce haploid gametes in sexually reproducing organisms. It contrasts with mitotic (mitosis) division and is essential for sexual reproduction and genetic variation. The term is often used in Hungarian-language scientific literature to denote meiotic phenomena.

Meiosis consists of two consecutive divisions, meiosis I and meiosis II, preceded by a single round of DNA replication. During meiosis I, homologous chromosomes pair and exchange genetic material through crossing over (recombination) in prophase I, and homologs segregate to opposite poles in anaphase I. This reduction division halves the chromosome number and creates genetic diversity through recombination and independent assortment of chromosomes.

Meiosis II resembles mitosis, separating sister chromatids to form four genetically distinct haploid cells. The stages of prophase I infer leptotene, zygotene, pachytene, diplotene and diakinesis, followed by metaphase I, anaphase I, telophase I and cytokinesis; meiosis II includes prophase II, metaphase II, anaphase II and cytokinesis.

Meiotikus has significance in evolution by increasing genetic variation; errors such as nondisjunction can cause aneuploidy (e.g., Down syndrome). Regulation occurs via cell-cycle checkpoints and recombination control. Differences exist among organisms in timing and product of meiosis; in fungi, plants, and animals, gametogenesis uses meiosis with variations in timing.