Dictionary > Leptotene

Leptotene

Definition
noun
The first sub-stage of prophase I of meiosis I in which the chromosomes at this stage are characteristically threadlike in form
Supplement
Meiosis is form of cell division that gives rise to genetically diverse sex cells or gametes. It is comprised to two successive nuclear divisions namely meiosis I and meiosis II. Meiosis I is comprised of four stages: prophase I, metaphase I, anaphase I, and telophase I. Prophase I is the first stage and consists of the following sub-stages: leptotene, zygotene, pachytene, diplotene and diakinesis.
Leptotene is the first sub-stage and it is when the replicated chromosomes start to condense into long strands inside the nucleus. The chromosomes at this stage are threadlike (thus, the term leptos, meaning thin threads). And in each chromosome, chromomeres (i.e. serially aligned beads or granules resulting from local coiling of a continuous DNA thread) can be seen. The sister chromatids that make up the chromosome are so closely associated together at this point. Because of this, the sister chromatids appear to be a single strand since they are visually indistinguishable from each other.
Word origin: Greek leptós (“thin”) + –tene (“thread”)
Synonym:

  • leptonema

See also:

  • prophase I
  • meiosis I
  • zygotene
  • pachytene
  • diplotene
  • diakinesis
  • chromomere


  • You will also like...

    Pollution in Freshwater Ecosystems
    Pollution in Freshwater Ecosystems

    There are many environmental factors that arise due to the usage of water in one way or another and for every action tha..

    Disturbance on a still water
    Abiotic Factors – Water Conditions

    A still body of water may be disturbed by a variety of factors. One of them is wind. In fact, it is considered as the pr..

    Biological Viruses
    Biological Viruses

    Viruses possess both living and non-living characteristics. This unique feature distinguishes them from other organisms...

    A chart depicting Mendel's Law of Dominance
    Mendel’s Law & Mendelian Genetics

    One of Mendel’s law of inheritance is the “law of dominance”. Read this tutorial to know more about this form of i..

    green leaf - close up view
    Leaves

    Leaves are the major photosynthetic organ of a plant. Apart from that, they are also crucial to water movement. In this ..

    Homeostasis by water regulation
    Homeostasis of Organism Water Regulation

    Osmoregulation is the regulation of water concentrations in the bloodstream, effectively controlling the amount of water..

    Related Articles...

    No related articles found

    See all Related Topics