lecture_14_notes

lecture_14_notes - Life cycles Most "large"...

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Life cycles Most "large" eukaryotes are diploid Chromosomes have unique characteristics In the plant Arabidopsis, there are five chromosome types: 1, 2, 3, 4, 5 Each chromosome is characterized by its size, position of centromere (the constriction) and sequence. Staining with certain substances reveals zones (stripes). Diploid cells have two chromosome of each type: for Arabidopsis, two 1, two 2, etc, total = 10 The two chromosome are defined as homologous and referred to as homologs Diploidy is defined as a 2N stage, where N is the gametic chromosome number The two chromosomes of a type are identical or nearly identical, depending on the species and its mating habits Diploid cells cannot mate (fusion of male and female cell) because that would cause the progeny to have double the chromosome number So, diploid organisms like animal and plants produce specialize cells, the gametes that have only 1 copy of each chromosomes. This genetic make-up is called haploid Gametes and some small eukaryotes are haploid Haploid cells have one chromosome of each type. For Arabidopsis, total = 5 Haploid cells can mate. The resulting cell is diploid as the chromosome number is doubled
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This note was uploaded on 06/07/2009 for the course BIS BIS2A taught by Professor Lucacomai during the Spring '09 term at UC Davis.

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lecture_14_notes - Life cycles Most "large"...

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