Biology 1001A Lecture Notes - Lecture 12: Mendelian Inheritance, Zygote, Centromere
4 Dec 2015
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Document Summary
Zygotes bring dna from two different parents into the same: in animal life cycles the zygote divides by mitosis, in plant life cycles the zygotes and the spores divide by. Recombination during meiosis creates new combinations of: as you go towards tipis of chromosomes recombination frequency increases. Decreases as you go towards centromere: random: all the possible outcomes are equally frequent. Random vs. unpredictable: cells cant choose where the recombination happens, recombination is unpredictable and undirected. Alignment of one homologous pair is independent of others: random recombination mechanism for generating diversity (random all outcomes are equally likely) Distribution of variation is not random: tp53 mutations are not evenly distributed, insertions and deletions (blue and red spots at bottom, development of soma vs. germ line in c. elegans. Only variation in germ line is available for evolution. Some of cells in germ line specialized to make gametes. Some cells give rise to sex cells gametic cells.
