Dictionary > Parthenogenesis


A form of asexual reproduction wherein the offspring develops from the egg or female gamete without the prior fertilization from the male gamete
Parthenogenesis is regarded as a form of asexual reproduction since a zygote forms without the union between female and male gametes. It is a common means of reproduction in plants, invertebrates (such as water fleas, aphids, stick insects, some ants, bees and parasitic wasps), and vertebrates (such as some reptiles, amphibians, fish, and few birds).
Parthenogenesis may be apomictic or automictic. Apomictic parthenogenesis is one in which the mature egg cells produced through mitosis develop directly into embryos. The offspring are full clones of the mother. In automictic parthenogenesis, the gametes undergo meiosis and therefore are haploid.
Parthenogenesis may be facultative or obligate. A facultative parthenogenesis is one in which the female reproduce either sexually or asexually. Mayflies are capable of facultative parthenogenesis. They undergo parthenogenesis when viable males are absent from the habitat. Obligate parthenogenesis is one in which the organism reproduce only by asexual means. Certain species of reptiles (most of them are lizards) are capable of obligate parthenogenesis.
Pathenogenesis may also be arrhenotokous, thelytokous, or deuterotokous. The arrhenotolous parthenogenesis (arrhenotoky) is a form of parthenogenesis in which the unfertilized eggs develop into males. Thelytokous parthenogenesis (thelytoky) is a form of parthenogenesis in which unfertilized eggs develop into females. Deuterotokous parthenogenesis (deuterotoky) is one in which the unfertilized eggs may develop into males and females.
Word origin: from Ancient Greek parthénos (“virgin”) + génesis (“origin, creation, generation”)

  • parthenogeny
  • apomixia

See also:

  • asexual reproduction
  • arrhenotoky
  • thelytoky
  • Related form(s):

    • parthenogenetic (adjective, of, pertaining to, or produced by, parthenogenesis)

    You will also like...

    Darwin's Finches - Natural Selection
    Darwin’s Finches & Natural Selection

    Darwin's Finches are an example of natural selection in action. They are an excellent example of the way species' gene p..

    Homeostatic Mechanisms and Cellular Communication
    Homeostatic Mechanisms and Cellular Communication

    Homeostasis is the relatively stable conditions of the internal environment that result from compensatory regulatory res..

    Peppered moth ("Biston betularia") melanic and light form
    Theory of Natural Selection

    This tutorial investigates the genetic diversity in more detail. It also delineates how certain alleles are favored over..

    Developmental Biology
    Developmental Biology

    Developmental biology is a biological science that is primarily concerned with how a living thing grows and attains matu..

    An artist depiction of a Precambrian multicellular life form.
    The Evolution of Cell Organelles

    The nucleus containing the genetic material, DNA, and the mitochondria, well-identified as the "powerhouse of the cell",..

    An artist's depiction of the origin of amphibians
    Amphibians & Early Reptiles

    Obtaining air outside an aquatic environment required species to acquire suitable adaptations, and this was the case of ..