Biology 1001A Lecture Notes - Lecture 4: Genetic Recombination, Covalent Bond, Meiosis
6 Nov 2016
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Dna molecules to line up and recombine precisely because they have the same size, shape, and gene location: once homologous region of dna are paired, enzymes break a covalent bond in each of the four sugar-phosphate backbones. The free ends of each backbone are then exchanged and reattached to those of the other dna molecule. The result is two recombined molecules: cutting and pasting four dna backbones results in one recombination event the stage of meiosis when recombination occurs, during meiosis, homologous chromosomes are paired in prophase i. They may undergo recombination by exchanging segments during this time products of meiosis in animals vs. plants, fungi and algae: meiosis in animals: zygotes divide by mitosis, gametes produced by meiosis. In plants: spores and zygotes divide by mitosis in haploid and diploid phases. In fungi and algae: spores divide by mitosis, formed by meiosis.
