1. Cell Reproduction  Prokaryotes Bacteria  Eukaryotes Plants & animals

2. Prokaryotes  Lack a nucleus  Have a single chromosome  Reproduce by binary fission  Include bacteria

3. Steps in Binary Fission  Used by bacteria  Cells increase their cell mass slightly  DNA & cell components are replicated  Each cell divides into 2 daughter cells

4. Binary Fission of Bacterial Cell

5. E. Coli Dividing by Binary Fission

6. Eukaryotes  Contain a nucleus & membrane bound organelles  Asexually reproduce cells by mitosis

7. Cell Cycle  Stages in growth & division  G1 Phase  S Phase  G2 Phase  M Phase  Cytokinesis

8. G1 Phase  First growth stage  Cell increases in size  Cell prepares to copy its DNA

9. Synthesis Phase  Copying of all of DNA’s instructions  Chromosomes duplicated

10. G2 Phase  Time between DNA synthesis & mitosis  Cell continues growing  Needed proteins produced

11. M(mitosis) Phase  Cell growth & protein production stop  Cell’s energy used to make 2 daughter cells  Called mitosis or karyokinesis (nuclear division)

13. Life Cycle of a Cell Mitosis is a cycle with no beginning or end.

14. Interphase – Resting Stage  Cells carrying on normal activities  Chromosomes aren’t visible  Cell metabolism is occurring  Occurs before mitosis

15. Interphase

17. Stages of Mitosis  Prophase  Metaphase  Anaphase  Telophase

18. Cells Undergoing Mitosis

19. Steps in Prophase  DNA coils tightly & becomes visible as chromosomes  Nuclear membrane disappears  Nuceolus disappears  Centrioles migrate to poles  Spindle begins to form

21. Prophase,c4

22. Prophase

23. Eukaryotic Chromosome

24. Human Chromosomes

25. Metaphase

27. Steps in Metaphase  Spindle fibers from centrioles attach to each chromosome  Cell preparing to separate its chromosomes  Cell aligns its chromosomes in the middle of the cell

28. Metaphase,b4

29. Anaphase

30. Mitotic Spindle

32. Steps in Anaphase  The centromeres divide. Sister chromatids separate and move toward the corresponding poles.  Spindle fibers shorten so chromosomes pulled to ends of cell

33. Anaphase,a4

34. Telophase Plant Animal

35. Steps in Telophase  Separation of chromosomes completed  Cell Plate forms in plants  Cleavage furrow forms in animals  Nucleus & nucleolus reform  Chromosomes uncoil

36. Telophase,d4

38. Cytokinesis Cell Plate Forming in Plant Cells

39. Cytokinesis  Occurs after chromosomes separate  Forms two, identical daughter cells