Dictionary » P » Prophase I

Prophase I

Definition

noun

The first stage in the first meiotic division of meiosis. This stage is characterized by having five sub-stages namely leptotene, zygotene, pachytene, diplotene and diakinesis. It highlights the exchange of DNA between homologous chromosomes via a process called homologous recombination and the cross-over at chiasma(ta) between non-sister chromatids. Thus, this stage is important to increase genetic variation. This stage then ends with the disintegration of the nucleolus and the nuclear membrane.


Supplement

Since meiosis consists of two consecutive nuclear divisions, prophase occurs twice. Thus, there are prophase I and prophase II.


See also: prophase II, meiosis I


Please contribute to this project, if you have more information about this term feel free to edit this page



This page was last modified 13:02, 26 October 2009. This page has been accessed 35,464 times. 
What links here | Related changes | Permanent link