1. Reproduction C-11-1

2. There are many types of reproduction

3. Reproduction C-11-1 Binary fission Done by bacteria

4. Reproduction C-11-1 Asexual Just split in half  Amoebas

5. Reproduction C-11-1 Fragmentation Pieces split off and each piece becomes a new organism  Starfish

6. Reproduction C-11-1 Budding Whole organism grows off another and then splits off  Hydra

7. Reproduction C-11-1 Parthenogenesis Female makes viable egg that grows without being fertilized  Water fleas

8. Reproduction C-11-1 Sexual 2 parents give genetic material to make offspring that are genetically different from them  Most eukaryotes * Advantage – genetic diversity

9. Reproduction C-11-1 Germ cells give rise to gametes = sex cells When gametes from the parents combine, the result is called a zygote

10. Reproduction C-11-1 Gametes = haploid 1 of each type of chromosome (1n) Zygote = diploid 2 of each type of chromosome (2n)

11. Reproduction C-11-1 For humans In each gamete, the 1n = 23 In each diploid cell the 2n = 46

12. Reproduction C-11-1 Homologous chromosomes Chromosomes of the same type Ex: chrom. 1 from mom is homologous to chrom. 1 from dad

13. Reproduction C-11-1 Autosomes Chromosomes that are not sex chromosomes

14. Meiosis C-11-2 Meiosis is cell division that makes daughter cells with half the number of chromosomes than the parent cell

15. Meiosis C-11-2 2 divisions take place: Meiosis I - 1 st division Prophase I  Chromosomes condense  Nuclear envelope breaks down  Homologous chromosomes pair up  Crossing over can occur

16. Meiosis C-11-2 Metaphase I Spindle fibers move homologous chromosomes to middle of cell Homologous remain together

17. Meiosis C-11-2 Anaphase I Homologous chromosomes move to opposite poles

18. Meiosis C-11-2 Telophase I Chromosomes gather at the poles Cytoplasm starts to divide

19. Meiosis C-11-2 Cytokinesis Cytoplasm divides

20. Meiosis C-11-2 Now we have 2 cells with ½ the number of chromosomes... But we still have 2 chromatids on each chromosome We need to split these again

21. Meiosis C-11-2 Meiosis II Prophase II  New spindles form

22. Meiosis C-11-2 Metaphase II Chromosomes line up in the middle of cell

23. Meiosis C-11-2 Anaphase II Chromosomes divide at centromeres and chromosomes move to either pole

24. Meiosis C-11-2 Telophase II Nuclear envelope forms around each set of chromosomes Spindles disappear Cell begins to divide

25. Meiosis C-11-2 Cytokinesis Cell divides

26. Meiosis C-11-2 This results in a total of 4 new haploid cells that are genetically different from the parent cell.

27. Meiosis C-11-2 When this process occurs, the homologous chromosomes will be randomly distributed Called independent assortment

28. Meiosis C-11-2 Also, the fertilization of gametes is random as well. There are about 64 trillion combinations of chromosomes

29. Multicellular Life Cycles C-11-3 Diploid life cycles: Most animals have this Most of life is spent in this state All cells except gametes are diploid  To make gametes, meiosis must occur...slightly different in males and females:

30. Multicellular Life Cycles C-11-3 Spermatogenesis: Oogenesis:

31. Multicellular Life Cycles C-11-3 Haploid life cycle: Happens in most fungi and some protist Most of life spent in haploid state Only diploid structure is the zygote New haploid cells go through mitosis to make multicellular haploid individuals

32. Multicellular Life Cycles C-11-3 p 258

33. Multicellular Life Cycles C-11-3 Alternation of generations: Some organisms alternate between diploid and haploid phases Ex: PLANTS  The multicellular diploid phase = sporophyte  Produces spores through meiosis  Spore forms a multicellular gametophyte which is haploid  Gametophyte makes gametes which when fertilized give rise to sporophyte

34. Multicellular Life Cycles C-11-3