Meiosis and producing genetically diverse offspring

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Meiosis and producing genetically diverse
offspring Bonus 1 and 2 are posted
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CB 17.3
Protein
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CB 13.5
Meiosis producing gametes
For life to exist, the information (genes) must
be passed on.
Mitosis producing more cells
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CB 12.4
Mitosis A DNA Perspective
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Mitosis plays a role in

• Growth and Development
• Repair and Turnover of Cells
• Reproduction
• Asexual

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The Cell Cycle
CB 12.5
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start of mitosis
CB 12.6
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CB 13.5
Meiosis producing gametes
For life to exist, the information (genes) must
be passed on.
Mitosis producing more cells
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Asexaul Reproduction
Sexaul Reproduction
vs.
extremely low genetic diversity
greater genetic diversity
How does sexual reproduction generate genetic
diversity?
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Allele for low express (short)
Allele for black hair
Allele for sickle cell Hb
Gene for growth hormone
Gene for hemoglobin
Gene for hair color
Diploid chromosomes
Allele for black hair
Allele for high express (tall)
Allele for normal Hb
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Each pair of chromosomes is comprised of a
paternal and maternal chromosome
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sister chromatids replicated DNA
(chromosomes) tetrad pair of sister chromatids
CB 13.4
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CB 13.7
X 23 in humans
Meiosis splits apart the pairs of chromosomes.
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haploid
X 23 in humans
X 23 in humans
diploid
X 23 in humans
Inheritance The interaction between genes
inherited from Mom and Dad.
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Asexaul Reproduction
Sexaul Reproduction
vs.
extremely low genetic diversity
greater genetic diversity
How does sexual reproduction generate genetic
diversity?
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CB 13.7
X 23 in humans
Meiosis splits apart the pairs of chromosomes.
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CB 13.11
Crossing-over (aka Recombination)
DNA cut and religated
DNA cut and religated
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CB 13.11
Crossing-over Proteins in the cell cut and
religate the DNA, increasing the genetic
diversity in gametes.
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CB 13.10
Independent Assortment (aka Random Assortment)
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CB 13.10
Independent Assortment
2 possibilities for each pair, for 2 pairs 22 4
combinations
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CB 13.10
Independent Assortment
2 possibilities for each pair, for 23 pairs 223
8,388,608 combinations
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CB 13.9
Crossing-over
Meiosis In humans, crossing-over and independent
assortment lead to over 1 trillion possible
unique gametes. (1,000,000,000,000)
Meiosis I
(Ind. Assort.)
Meiosis II
4 Haploid cells, each unique
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Asexaul Reproduction
Sexaul Reproduction
vs.
extremely low genetic diversity
greater genetic diversity
How does sexual reproduction generate genetic
diversity?