Meiosis

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Meiosis

• Unlike Mitosis where you have two identical cells
  (a cell splits) at the end of Meiosis you have 4
  cells each having half the number of chromosomes
  so that if the little one gets united with
  another different cell (from mom or dad it
  returns to having a full set of chromosomes

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• Diploid set of chromosomes from each parent 2n
• Haploid cell containing only one kind of
  chromosome n

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• http//onlinetc.its.brooklyn.cuny.edu/Core81/chap7
  .htmljump1

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Meiosissexual reproduction

• Has 2 separate divisions
• End result in males is 4 sperm
• In females is 3 ootids and one egg. WHY??

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Genetic recombination

• In mitosis cells are identical. In meiosis
  crossing over rearranges allele combinations
  resulting in new combinations from each parent.

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nondisjunction
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polyploidy

• Results in more than the usual number
• Rare in animals as it usually results in death
• But in plants is very useful and common
• Wheat HEXAPLOID 6n
• Apples 3n triploid

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Review of meiosis
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Overall review