1. Words to think about in this unit. Mitosis Meiosis Chromosomes Chromatids Homologous chromosomes Cell cycle Cancer Haploid vs. diploid Somatic cells versus germ line cells

2. Mitosis and Meiosis Sea star morula

4. Sea Urchin Development

5. In prokaryotes, cell division is simple= Binary Fission forms 2 daughter cells Single circular DNA molecules

6. Binary Fission

7. Different story for Eukaryotes… WHY? Bigger More DNA many linear chromosomes Packaged differently than prokaryotes Chromosome= long DNA molecule packaged with proteins (called ____________)into compact shape.

8. OVERVIEW Chromosomes composed of CHROMATIN= Protein and DNA 1 human chrom= 140 million nucleotides 1 chromosome stretched out = 2 inches

9. Mitosis and Meiosis Mitosis: cell ÷ in somatic cells Meiosis: cell ÷ in germ cells

10. Cell cycle- cell division and the events that prepare a eukaryotic cell for division

11. Chromosome When chromosomes replicate, form IDENTICAL sister chromatids. Centromere-connects 2 sister chromatids

13. Each member of pair carries SIMILAR info!

15. Diploid(2n) versus haploid(n)

16. QUIZ

17. QUIZ In the cell cycle, what does “S” stand for? What is the definition of somatic cell? What does this picture represent?

18. Mitosis

19. Mitosis

21. Meiosis

22. Meiosis

23. Mitosis versus meiosis

24. Independent Assortment

25. Crossing over

26. Nondisjunction in meiosis I

27. Nondisjunction in meiosis II

28. Fertilization after nondisjunction