Yahoo Answers is shutting down on May 4th, 2021 (Eastern Time) and beginning April 20th, 2021 (Eastern Time) the Yahoo Answers website will be in read-only mode. There will be no changes to other Yahoo properties or services, or your Yahoo account. You can find more information about the Yahoo Answers shutdown and how to download your data on this help page.
Trending News
Can you suggest an adaptive value for reatining the tetrad formation?
This question came up in one of my biology tasks, and I have no idea what it means. Its reffering to pollen. Is there such thing as the tetrad formation in pollen? Detailed explanation of the tetrad for formation would be appreciated too.
sorry i meant retaining*
1 Answer
- DNAunionLv 71 decade agoFavorite Answer
A tetrad is what is formed when homologous chromosomes pair up and synapse during prophase I of meiosis. Since each chromosome at that point consists of 2 sister chromatids joined together at their centromere, when two homologous chromosomes synapse the result has a total of four chromatids (tetra = 4, hence, tetrad).
In a tetrad, crossing over occurs, which is the exchanging of corresponding segments of non-sister chromatids of homologous chromosomes. In simpler terms, a single crossing over event might take a segment from maternal chromosome 3 and swap it with the same segment of the paternal chromosome 3, resulting in 2 chromosomes that have both maternal and paternal segments. This exchange of chromosomal segments shuffles the genetic information, creating new combinations of alleles, and so creates greater variety among the gametes. This in turn produces greater genetic variation among individuals, which is advantageous for evolution.