Biology 1001A Lecture Notes - Lecture 10: Meiosis, Ploidy, Mitosis
28 Mar 2016
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Document Summary
Independent study outcomes: products of meiosis in animals vs. plants, fungi and algae. Plants & some fungi/algae: mostly diploid phase. Product of meiosis is spores that is followed by mitosis which produces gametes gametes-followed by gamete. Gametes from mitosis production: timing of meiosis in vertebrate life cycles, in female mammals: oocytes stuck in meiotic arrest, sexual recombination has already occurred, fertilization triggers continuation of meiosis. In males: continuously sexually recombining : main differences between meiosis and mitosis. Produces 4 daughter cells: genetically different, haploid gametes (n, only occurs in diploid organisms. Produces 2 daughter cells: genetically identical, diploid products (2n, occurs in all organisms. Prophase i: 4c, 2n telophase i: 2c, 1n telophase ii 1c, 1n: mechanism of recombination during prophase, recombination occurs between homologues: regions of dna that are very similar (but not identical), in the sequence of bases. Once homologues regions are paired, enzymes break a covalent bond in each of the four sugar-phosphate backbones.
