Meiosis

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Meiosis Reproduction
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Asexual Reproduction

• Identical offspring (clones)
• Mitosis
• Different kinds
• Binary fission
• Budding
• Fragmentation
• Regeneration

3
Sexual Reproduction

• Two parents
• Haploid gametes
• Genetic Variation
• Similar to parents
• Similar to each other

4
Haploid vs. Diploid

• HAPLOID
• 1n
• One copy of each chromosome

• DIPLOID
• 2n
• Two copies of each chromosome
• Homologous chromosomes

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Human Female Karyotype
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Human Male Karyotype
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Overview of Meiosis

• Meiosis halves the number of chromosomes. When
  reproductive cells unite there is normal number
  of chromosomes.
• Diploid parent cell divides twice to make haploid
  gametes

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Meiosis I
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Meiosis II
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Mitosis vs. Meiosis
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Genetic Variation

• Independent Assortment 50/50 chance that gamete
  gets maternal/paternal homologous chromosome
• Random Fertilization-
• Crossing over increases genetic variation even
  more

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Crossing Over

• Increases genetic variation
• Happens during Prophase I

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Gamete Possibilities(due to Independent
Assortment)
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• Oogenesis Produces gametes in female animals
• Spermatogenesis Produces gametes in male animals
• Life cycles
• Haploid
• Diploid
• Alternation of generations