Meiosis and producing genetically diverse offspring Discussions start

Meiosis and producing genetically diverse offspring Discussions start this week.

Fig 16. 10 Protein

Fig 12. 3 {Meiosis: producing gametes} For life to exist, the information (genes) must be passed on. {Mitosis: producing more cells}

Mitosis: A DNA Perspective

Fig 11. 3 Sister chromatids are replicated DNA

Mitosis plays a role in: • Growth and Development • Repair and Turnover of Cells • Reproduction –Asexual

Fig 11. 5 The Cell Cycle

start of mitosis Fig 11. 7

Fig 12. 3 {Meiosis: producing gametes} For life to exist, the information (genes) must be passed on. {Mitosis: producing more cells}

Fig 12. 13 Asexual Reproduction extremely low genetic diversity vs. Sexual Reproduction greater genetic diversity How does sexual reproduction generate genetic diversity?

Gene for growth hormone Gene for brown hair pigment Gene for blue eye pigment Gene for hemoglobin Gene for DNA polymerase Haploid chromosomes

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

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

sister chromatids= replicated DNA (chromosomes) tetrad= pair of sister chromatids Tbl 12. 2

Fig 12. 2 Meiosis splits apart the pairs of chromosomes. X 23 in humans

haploid X 23 in humans diploid X 23 in humans Inheritance = The interaction between genes inherited from Mom and Dad.

Fig 12. 13 Asexual Reproduction extremely low genetic diversity vs. Sexual Reproduction greater genetic diversity How does sexual reproduction generate genetic diversity?

Fig 12. 2 Meiosis splits apart the pairs of chromosomes. X 23 in humans

Fig 12. 7 Crossing-over (aka Recombination) DNA cut and religated

Fig 12. 7 Crossing-over: Proteins in the cell cut and religate the DNA, increasing the genetic diversity in gametes.

Fig 12. 7

Fig 12. 9 Independent Assortment (aka Random Assortment)

Fig 12. 9 Independent Assortment 2 possibilities for each pair, for 2 pairs 22 = 4 combinations

Fig 12. 9 Independent Assortment 2 possibilities for each pair, for 23 pairs 223 = 8, 388, 608 combinations

Fig 12. 2 Crossingover Meiosis: (Ind. Assort. ) In humans, crossing -over and independent assortment lead to over 1 trillion possible unique gametes. (1, 000, 000) Meiosis II 4 Haploid cells, each unique

Fig 12. 13 Asexual Reproduction extremely low genetic diversity vs. Sexual Reproduction greater genetic diversity How does sexual reproduction generate genetic diversity?