Bonus #1 and #2 are posted. Discussions start this week Th and F.

CB 17.3 Protein

For life to exist, the information (genes) must be passed on. CB 13.5 {Meiosis: producing gametes} For life to exist, the information (genes) must be passed on. {Mitosis: producing more cells}

How does sexual reproduction generate genetic diversity? Asexaul Reproduction Sexaul Reproduction vs. extremely low genetic diversity greater genetic diversity How does sexual reproduction generate genetic diversity?

Gene for growth hormone Gene for hair color Gene for hemoglobin Allele for low express (short) Allele for black hair Allele for sickle cell Hb Gene for growth hormone Gene for hair color Gene for hemoglobin Diploid chromosomes Allele for high express (tall) Allele for black hair Allele for normal Hb

Each pair of chromosomes is comprised of a paternal and maternal chromosome

Two processes generate genetic diversity during sexual reproduction. Asexaul Reproduction Sexaul Reproduction vs. extremely low genetic diversity greater genetic diversity Two processes generate genetic diversity during sexual reproduction.

Crossing-over: Proteins in the cell cut and religate the DNA, increasing the genetic diversity in gametes. CB 13.11

CB 13.11 Crossing-over: Proteins in the cell cut and religate the DNA, increasing the genetic diversity in gametes.

2 possibilities for each pair, for 2 pairs CB 13.10 Independent Assortment 2 possibilities for each pair, for 2 pairs 22 = 4 combinations

2 possibilities for each pair, for 23 pairs CB 13.10 Independent Assortment 2 possibilities for each pair, for 23 pairs 223 = 8,388,608 combinations

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

CB 13.8

CB 13.8 4 haploid cells

CB 13.9

CB 13.5 {Producing gametes} Sexual reproduction creates genetic diversity by combining DNA from 2 individuals, but also by creating genetically unique gametes. {Producing more cells}

CB 13.6 Different organisms have different patterns of haploid and diploid stages

Asexual Reproduction genetically identical to parent (this tree can reproduce both sexually and asexually)

Why does sexual reproduction exist? Cons: Need two individuals Hard to find mate Diseases/Competition Pros: Genetic diversity or Replace damage DNA

Plant Evolution: different plants have different ploidy for the different parts of their lifecycle. CB 29.7

CB 29.8 and .12 Haploid dominant (algae) Diploid dominant (fern)

Why does sexual reproduction exist? Cons: Need two individuals Hard to find mate Diseases/Competition Pros: Genetic diversity or Replace damage DNA

Bonus #1 and #2 are posted. Discussions start this week Th and F.