Asexual Reproduction

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Asexual Reproduction
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Sexual Reproduction

• recombination of genetic material
• More combinations means there is a higher chance
  at least some will survive a catastrophe
• Offspring not identical to parents

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Sexual Reproduction

• Union 2 haploid (1n) gametes (Such as Sperm and
  Egg)to form a diploid (2n) Zygote

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Diploid vs Haploid

• These terms refer to the number of sets of
  chromosomes an organism has.
• Humans are Diploid, we have two sets of
  chromosomes 46 total or 23 Pairs of Homologous
  chromosomes
• Sperm and eggs are haploid they only have 23
  chromosomes each.
• When sperm and egg join the resulting zygote will
  have 46 chromosomes

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Homologous Chromosomes

• Homologous means Like or Same
• Homologous chromosomes are chromosomes that code
  for the same genes. Remember that a gene codes
  for a protein that may result in a trait.
• The homologous chromosomes may have different
  version of the genes called Alleles They code
  for the same trait but may have different forms
  or colors.

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Meiosis

• The process of making a haploid cell
• Also known as a reduction division because the
  number of chromosomes is reduced in this process.
  
• Two stages
• Meiosis I
• Meiosis II
• Results in 4 haploid (1N) Gamates

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Meiosis I

• DNA is Replicated
• Homologous chromosomes line up in metaphase.
• This is when genetic recombination can occur so
  not all offspring from the same pair will be
  identical! Very important for variation within a
  population and for the rise of new species.
• Results in 2 haploid cells

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Meiosis I
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Meiosis II

• DNA in NOT replicated in the two haploid cells
• chromatids separate and divide
• results in 4 haploid (1n) cells.

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Meiosis II