(Picture is of overall Process, does not name particular phases named below)
III. Metaphase I - Tetrads line up at the equator.
IV. Anaphase I - Homologous chromosomes split apart and travel toward the poles.
V. Telophase I - Cell divides into 2 "haploid" cells. This division is called the reduction division because the chromatid pairs are still together and this significantly reduces the amount of allelic information.
VI. Prophase II - 2 cells now. No replication, tetrad formation, nor crossing over.
VII. Metaphase II - Chromatid pairs line up at the equators.
VIII. Anaphase II - Chromatids split apart and move to the poles
IX. Telophase II - Cells split into 4 genetically unique haploid gametes.
Why is Meiosis So Important?
1. Makes sure that exactly 1/2 of the information comes from a sperm cell and 1/2 from the egg cell.
2. Diploidy- Chromosomes are in pairs. We have backup for "bad" copies.
3. Genetic Variablity
a. We are 1/2 and 1/2 of 2 uniqure parents.
b. Crossing over - # 1 source of varablitity
c. Independent Assortment - in humans there are 2 to the 23 power number of combos of homologues reaching a sperm or egg cell.
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