Chiasma
Chiasma or crossover refers to the visible point where paired maternal and paternal homologous chromosomes join during meiosis 1 and then crossover. This recombination occurs when a segment of one paternal chromatid is replaced by the complementary form of the other maternal chromatid. [1]
There are 2 nuclear divisions in meiosis, and a chiasma forms in the first division of meiosis 1. The duplicated homologs align with each other and swap genetic information (recombination).
Crossover happens between 2 non-sister chromatids. The chiasma can be seen at the point where the homologs join in prophase 1, when the synaptonemal complex disassembles and begin to separate. [2]
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- ↑ Bruce Alberts, Alexander Johnson, Julian Lewis, Martin Raff, Keith Roberts and Peter Walter, 2008. Molecular biology of the cell. 5th edition. New York: Garland science.
- ↑ Bruce Alberts, Alexander Johnson, Julian Lewis, Martin Raff, Keith Roberts and Peter Walter, 2008. Molecular biology of the cell. 5th edition. New York: Garland science.