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  2. Meiosis - Wikipedia

    en.wikipedia.org/wiki/Meiosis

    Meiosis (/ m aɪ ˈ oʊ s ɪ s / ⓘ; from Ancient Greek μείωσις (meíōsis) 'lessening', (since it is a reductional division) [1] [2] is a special type of cell division of germ cells in sexually-reproducing organisms that produces the gametes, the sperm or egg cells.

  3. Oocyte - Wikipedia

    en.wikipedia.org/wiki/Oocyte

    An oocyte (/ ˈ oʊ ə s aɪ t /, oöcyte, or ovocyte is a female gametocyte or germ cell involved in reproduction. In other words, it is an immature ovum, or egg cell. An oocyte is produced in a female fetus in the ovary during female gametogenesis. The female germ cells produce a primordial germ cell (PGC), which then undergoes mitosis ...

  4. Spermatogenesis - Wikipedia

    en.wikipedia.org/wiki/Spermatogenesis

    Spermatogenesis produces mature male gametes, commonly called sperm but more specifically known as spermatozoa, which are able to fertilize the counterpart female gamete, the oocyte, during conception to produce a single-celled individual known as a zygote.

  5. Spermatocyte - Wikipedia

    en.wikipedia.org/wiki/Spermatocyte

    Spermatogonia going through mitosis to form primary spermatocytes in Grasshopper testes. Spermatocytogenesis. At puberty, spermatogonia located along the walls of the seminiferous tubules within the testis will be initiated and start to divide mitotically, forming two types of A cells that contain an oval shaped nucleus with a nucleolus attached to the nuclear envelope; one is dark (Ad) and ...

  6. Sexual reproduction - Wikipedia

    en.wikipedia.org/wiki/Sexual_reproduction

    Some proteins and other features that are key for sexual reproduction may have arisen in bacteria, but sexual reproduction is believed to have developed in an ancient eukaryotic ancestor. [10] In eukaryotes, diploid precursor cells divide to produce haploid cells in a process called meiosis. In meiosis, DNA is replicated to produce a total of ...

  7. Resumption of meiosis - Wikipedia

    en.wikipedia.org/wiki/Resumption_of_meiosis

    At birth, meiosis arrests at the diplotene phase of prophase I. [7] Oocytes will remain in this state until the time of puberty. At the time of ovulation a surge of LH initiates the resumption of meiosis and oocytes enter the second cycle, which is known as oocyte maturation. Meiosis is then arrested again during metaphase 2 until fertilisation ...

  8. Origin and function of meiosis - Wikipedia

    en.wikipedia.org/wiki/Origin_and_function_of_meiosis

    Meiosis generates genetic variation in the diploid cell, in part by the exchange of genetic information between the pairs of chromosomes after they align (recombination). Thus, on this view, [28] an advantage of meiosis is that it facilitates the generation of genomic diversity among progeny, allowing adaptation to adverse changes in the ...

  9. Human reproductive system - Wikipedia

    en.wikipedia.org/wiki/Human_reproductive_system

    This occurs when certain types of germ cells undergo meiosis to split the normal diploid number of chromosomes (n=46) into haploid cells containing only 23 chromosomes. [10] Anatomy of the testis. In males, this process is known as spermatogenesis and occurs only after puberty in the seminiferous tubules of the testes.