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  2. Prophase - Wikipedia

    en.wikipedia.org/wiki/Prophase

    As it occurs after G2 of interphase, DNA has been already replicated when prophase begins. [1] Fluorescence microscope image of two mouse cell nuclei in prophase (scale bar is 5 μm). [2] Prophase (from Ancient Greek προ- 'before' and φάσις (phásis) 'appearance') is the first stage of cell division in both mitosis and meiosis.

  3. Meiosis - Wikipedia

    en.wikipedia.org/wiki/Meiosis

    This is an accepted version of this page This is the latest accepted revision, reviewed on 19 December 2024. Cell division producing haploid gametes For the figure of speech, see Meiosis (figure of speech). For the process whereby cell nuclei divide to produce two copies of themselves, see Mitosis. For excessive constriction of the pupils, see Miosis. For the parasitic infestation, see Myiasis ...

  4. Zygotene - Wikipedia

    en.wikipedia.org/wiki/Zygotene

    Zygotene (from greek "paired threads" [1]) is the second stage of prophase I during meiosis, the specialized cell division that reduces the chromosome number by half to produce haploid gametes. It follows the Leptotene stage and is followed by Pachytene stage.

  5. Chromosomal crossover - Wikipedia

    en.wikipedia.org/wiki/Chromosomal_crossover

    Crossing over occurs between prophase I and metaphase I and is the process where two homologous non-sister chromatids pair up with each other and exchange different segments of genetic material to form two recombinant chromosome sister chromatids. It can also happen during mitotic division, [1] which may

  6. Leptotene stage - Wikipedia

    en.wikipedia.org/wiki/Leptotene_stage

    The leptotene stage, also known as leptonema, is the first of five substages of prophase I during meiosis, ... [1]: 27 [2]: 353 ...

  7. Synapsis - Wikipedia

    en.wikipedia.org/wiki/Synapsis

    The SC protein scaffold stabilizes the physical pairing of homologous chromosomes by polymerizing between them during meiotic prophase. [2] During synapsis, autosomes are held together by the synaptonemal complex along their whole length, whereas for sex chromosomes , this only takes place at one end of each chromosome.

  8. 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 ...

  9. Bivalent (genetics) - Wikipedia

    en.wikipedia.org/wiki/Bivalent_(genetics)

    The formation of a bivalent occurs during the first division of meiosis (in the zygotene stage of meiotic prophase 1). In most organisms, each replicated chromosome (composed of two identical sister chromatids [1] [2]) elicits formation of DNA double-strand breaks during the leptotene phase. [3]