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...

    Kidneys
    Kidneys and Regulation of Water and Inorganic Ions

    The kidneys are responsible for the regulation of water and inorganic ions. Read this tutorial to learn about the differ..

    Crossing Over and Genetic Diversity
    Inheritance and Probability

    Gregor Mendel, an Austrian monk, is most famous in this field for his study of the phenotype of pea plants, including ..

    vitamins
    A Balanced Vitamin Diet – Vitamins A – K

    A balanced diet is essential to a healthy organism. Insufficiency or too much of a particular element or compound, such ..

    Ecological Research Measuring & Analysis
    Ecological Research: Measuring & Analysis

    This lesson is about the methods used for ecological research, such as quadrat and transect sampling, canopy fogging, an..

    Plant meristem
    Plant Meristems and Growth

    In plants, growth occurs in meristems, which are the site of repeated cell division of unspecialized cells. These cells ..

    Sugar Homeostasis
    Sugar Homeostasis

    The blood sugar level is regulated by two hormones. The mechanism behind this type of negative feedback control is descr..

    Related Articles...

    No related articles found

    See all Related Topics