1. Cellular Division

2. Cell Division All cells are derived from pre-existing cells
New cells are produced for growth and to replace damaged or old cells

3. Cell Division and Replication
Before cells divide they have to double cell structures, organelles, and their genetic information

4. How does DNA make more DNA?
DNA Replication
How does DNA make more DNA?

5. Identical Daughter Cells
Two identical daughter cells
Parent Cell

6. Keeping Cells Identical
Instructions for making cell parts are encoded in the DNA, so each new cell gets a complete set of the DNA molecules

7. Two new, identical DNA strands
DNA Replication
DNA must be copied or replicated before cell division
Each new cell will then have an identical copy of the DNA
Original DNA strand
Two new, identical DNA strands

8. Chromosomes

9. Chromosomes in Dividing Cells
Duplicated chromosomes are called chromatids & are held together by the centromere
Called Sister Chromatids

10. Cell Reproduction

11. Types of Cell Reproduction
Asexual Reproduction - a single cell divides to make 2 new identical cells
Eg. Mitosis
Sexual Reproduction - two cells (egg & sperm) that are NOT identical to the original cells unite to form a zygote Eg. Meiosis

12. The Cell Cycle

13. Cell Cycle Cell Grows in size (8hrs) Chromosomes duplicate (6hrs)

14. Cells prepare for Division Cell Divides into Identical cells
Cell Cycle
DNA Copied
Cells prepare for Division
Cells Mature
Daughter Cells
Cell Divides into Identical cells

15. Interphase - G1 Stage 1st growth stage after cell division
Cells mature by making more cytoplasm & organelles
Cell carries on its normal activities

16. Two identical copies of DNA
Interphase – S Stage
Synthesis stage
DNA is copied or replicated
Two identical copies of DNA
Original DNA

17. Interphase – G2 Stage 2nd Growth Stage
Occurs after DNA has been copied
All cell structures needed for division are made (e.g. centrioles)

18. Mitosis

19. Mitosis
Division of the nucleus
Has four stages

20. Four Mitotic Stages
Prophase
Metaphase
Anaphase
Telophase

21. Prophase

22. Prophase Chromatin in nucleus condenses to form visible chromosomes
Mitotic spindle forms from fibers in centrioles (animal)
Cytoplasm
Nucleolus
Nuclear Membrane
Chromosomes

23. Prophase Nuclear membrane & nucleolus are broken down
Spindle fibers attach to the centromere of each chromosome
Spindle finishes forming between the poles of the cell

24. Nucleus & Nucleolus have disintegrated
Prophase
Chromosomes
Nucleus & Nucleolus have disintegrated

25. Spindle Fiber attached to Chromosome
Kinetochore Fiber
Chromosome

26. Spindle Fibers
Polar fibers extend from one pole of the cell to the opposite pole
Kinetochore fibers extend from the pole to the centromere of the chromosome to which they attach

27. Sketch The Spindle

28. Metaphase

29. Metaphase
Chromosomes, attached to the kinetochore fibers, move to the center of the cell
Chromosomes are now lined up at the equator
Equator of Cell
Pole of the Cell

30. Metaphase
Spindle Fibers
Chromosomes lined at the Equator

31. Chromosomes at Equator
Metaphase
Chromosomes at Equator

32. Anaphase

33. Anaphase
Sister chromatids are pulled apart to opposite poles of the cell by kinetochore fibers

34. Sister Chromatids being separated
Anaphase
Sister Chromatids being separated

35. Telophase

36. Telophase Sister chromatids at opposite poles Spindle disassembles
Nuclear envelope forms around each set of sister chromatids
Nucleolus reappears
CYTOKINESIS occurs
Chromosomes reappear as chromatin

37. Cytokinesis Means division of the cytoplasm
Division of cell into two, identical halves called daughter cells

38. Cleavage furrow in animal cell Cell plate in plant cell
Cytokinesis
Cleavage furrow in animal cell
Cell plate in plant cell

39. Daughter Cells of Mitosis
Have the same number of chromosomes as each other and as the parent cell from which they were formed

40. Identical Daughter Cells
Chromosome number the same, but cells smaller than parent cell

41. Review of Mitosis

42. Name the Mitotic Stages:
Interphase
Name this?
Prophase
Telophase
Name this?
Metaphase
Anaphase

43. Name each stage as you see it occur?
Mitosis Animation
Name each stage as you see it occur?

44. Chromosomes during Metaphase of mitosis
Cell Division
Chromosomes during Metaphase of mitosis
Cytokinesis
Anaphase
Prophase
Metaphase
Telophase

45. Review of Mitosis

46. Telophase & Cytokinesis
Identify the Stages ?
Prophase ? ? ?
Metaphase
Anaphase
Prophase ? ? ?
Telophase & Cytokinesis
Anaphase
Telophase

47. Locate the Four Mitotic Stages in Plants
Anaphase
Telophase
Metaphase
Prophase

48. End of Mitosis
Coming Soon: Meiosis!