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  2. Polyploidy - Wikipedia

    en.wikipedia.org/wiki/Polyploidy

    Polyploidy occurs in some tissues of animals that are otherwise diploid, such as human muscle tissues. [45] This is known as endopolyploidy . Species whose cells do not have nuclei, that is, prokaryotes , may be polyploid, as seen in the large bacterium Epulopiscium fishelsoni . [ 46 ]

  3. Ploidy - Wikipedia

    en.wikipedia.org/wiki/Ploidy

    The extreme in polyploidy occurs in the fern genus Ophioglossum, the adder's-tongues, in which polyploidy results in chromosome counts in the hundreds, or, in at least one case, well over one thousand. [citation needed] It is possible for polyploid organisms to revert to lower ploidy by haploidisation. [citation needed]

  4. Gene duplication - Wikipedia

    en.wikipedia.org/wiki/Gene_duplication

    Polyploidy, or whole genome duplication is a product of nondisjunction during meiosis which results in additional copies of the entire genome. Polyploidy is common in plants, but it has also occurred in animals, with two rounds of whole genome duplication in the vertebrate lineage leading to humans. [4]

  5. List of organisms by chromosome count - Wikipedia

    en.wikipedia.org/wiki/List_of_organisms_by...

    The list of organisms by chromosome count describes ploidy or numbers of chromosomes in the cells of various plants, animals, protists, and other living organisms.This number, along with the visual appearance of the chromosome, is known as the karyotype, [1] [2] [3] and can be found by looking at the chromosomes through a microscope.

  6. Endoreduplication - Wikipedia

    en.wikipedia.org/wiki/Endoreduplication

    Endoreduplication (also referred to as endoreplication or endocycling) is replication of the nuclear genome in the absence of mitosis, which leads to elevated nuclear gene content and polyploidy. Endoreduplication can be understood simply as a variant form of the mitotic cell cycle (G1-S-G2-M) in which mitosis is circumvented entirely, due to ...

  7. Megakaryocyte - Wikipedia

    en.wikipedia.org/wiki/Megakaryocyte

    The cell eventually reaches megakaryocyte stage and loses its ability to divide. However, it is still able to replicate its DNA and continue development, becoming polyploid. [4] The cytoplasm continues to expand and the DNA amount can increase up to 64n in humans and 256n in mice.

  8. Diploidization - Wikipedia

    en.wikipedia.org/wiki/Diploidization

    The main goals of diploidization are: (1) To ensure proper gene dosage; and (2) to maintain stable cellular division processes. This process does not need to occur rapidly for all chromosomes in one or few steps. In recent polyploid events, segments of the genome may still remain in a tetraploid status.

  9. Hybrid speciation - Wikipedia

    en.wikipedia.org/wiki/Hybrid_speciation

    In cases where the first-generation hybrids are viable but infertile, fertility can be restored by whole genome duplication (polyploidy), resulting in reproductive isolation and polyploid speciation. Polyploid speciation is commonly observed in plants because their nature allows them to support genome duplications. Polyploids are considered a ...