Sheet1 Page 1 Lecture 12a: Chromosomes The carrier of traits?:-During Mendel's time, it was not known what carried the traits (genes)-Several things segregate during meiosis:->Chromosomes, centrioles, mitochondria, and chloroplasts-In 1902 it was suggested that it was chromosomes that possessed the "traits"->Supported by:-->Sperm contains very little cytoplasm-->Gametes are haploid-->Chromosomes segregate into gametes and assort randomly during meiosis Structure:-Chromatin is the entire collection of a cell's DNA and the associated proteins-Chromosomes are a single DNA strand and the associated proteins->Chromosomes change shape throughout the entire life of the cell-Lieaner, double-stranded DNA and histones (proteins) make nucleosomes-Bundles of nucleosomes further compact into condensed chromosome form Recombination:-One of the early objections to the "chromosomal theory" was that there were more traits than chromosomes->Now it is known that thousands of genes lie on a single chromosome
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This note was uploaded on 05/06/2008 for the course BIOL 121 taught by Professor Lopez during the Fall '07 term at Lansing.