Dictionary > Haploidy

Haploidy

Definition
noun
(genetics) The state of being haploid, that is having half of the set of homologous chromosomes in somatic cells
Supplement
Ploidy refers to the number of sets of homologous chromosomes in the genome of a cell or an organism. Each set is designated by n. Thus, the term haploidy would refer to a state of being haploid, that is having half of the set of the homologous chromosomes relative to that in somatic cells. In humans and many other living things, the somatic cell contains two copies of genes. As such, they are referred to as diploid. Gametogenesis, the process of producing gametes, ends up with sex cells that are haploid. That is, the number of chromosomes is halved. This is essential so that during the union of gametes the resulting zygote would have a diploid state and thus the integrity of chromosomal number throughout generations is eventually preserved. In humans, for instance, the germ cell (a sperm or an egg cell) is haploid, which means it contains only one of each of the 23 chromosomes of the human genome, or it only has half the diploid (2n) number of a human somatic cell (which is 46).
Word origin: from Greek diplous, double
Symbol: n
Compare:

See also:

  • chromosomes
  • ploidy
  • fertilization
  • somatic cell
  • gamete
  • ”Related term(s):

    • dihaploid

    Related forms:

  • haploid (adjective and noun)


    You will also like...

    Biological Cell Defense
    Biological Cell Defense

    Organisms employ different strategies to boost its defenses against antigens. Humans have an immune system to combat pat..

    Independent Assortment and Crossing Over
    Independent Assortment and Crossing Over

    This tutorial describes the independent assortment of chromosomes and crossing over as important events in meiosis. Read..

    Muscle
    Muscle

    Muscle cells are specialized to generate force and movement. Learn about the different types of muscle tissues in this t..

    Human Reproduction
    Human Reproduction

    Humans are capable of only one mode of reproduction, i.e. sexual reproduction. Haploid sex cells (gametes) are produced ..

    takahē
    Takahē (Porphyrio hochstetteri)

    Meet the colorful takahē, an extremely rare flightless bird. Find out more about its unique features and why they matte..

    Hormone Production
    Hormone Production

    Hormones are chemical messengers produced by specialized glands and they were produced by switching on the genes designe..