1. The Cell Cycle & Cell Division

2. Vocabulary Somatic Cell: Body Cell
Gamete: Sex cell (egg cell or sperm cell)
Diploid: 2n (Full set of chromosomes, somatic cells)
Haploid: n ( Half the amount of chromosomes, sperm or egg cells)
Crossing Over: Happens during Prophase 1, causes genetic variation.

3. The Cell Cycle

4. Animated Cycle

5. 2 Forms of DNA Chromatin – DNA that is all spread out
Chromosomes – DNA that is folded tightly together.

6. Numbers of Chromosomes differ between organisms
Chromosome Number
Amoeba 50
Carrot 18
Cat 32
Chimpanzee 48
Dog 78
Earthworm 36
Goldfish 94
HUMAN 46
Lettuce

7. MITOSIS

8. Mitosis
The process of cell division which results in the production of two daughter cells from a single parent cell.
The daughter cells are identical to one another and to the original parent cell.

9. Mitosis can be divided into stages
Interphase
Prophase
Metaphase
Anaphase
Telophase & Cytokinesis

10. Interphase The cell prepares for division
Animal Cell
DNA replicated
Organelles replicated
Cell increases in size
Plant Cell
DNA replicated
Organelles replicated
Cell increases in size

11. G1 Phase
Cell is duplicating its contents. Everything except the chromosomes. Checkpoint.

12. S Phase
All 46 Chromosomes are duplicated in this phase.

13. G2 Phase
Checkpoint makes sure that the duplicated DNA is all correct.

14. Interphase Plant Cell Animal Cell
Photographs from:

15. Prophase The cell prepares for nuclear division
Animal Cell
Packages DNA into chromosomes
Plant cell
Packages DNA into chromosomes

16. Prophase Plant Cell Animal Cell
Photographs from:

17. Metaphase The cell prepares chromosomes for division
Animal Cell
Chromosomes line up at the center of the cell
Spindle fibers attach from daughter cells to chromosomes at the centromere
Plant Cell
Chromosomes line up at the center of the cell
Spindle fibers attach from daughter cells to chromosomes at the centromere

18. Metaphase Plant Cell Animal Cell
Photographs from:

19. Anaphase The chromosomes divide
Animal Cell
Spindle fibers pull chromosomes apart
½ of each chromosome (called chromotid) moves to each daughter cell
Plant Cell
Spindle fibers pull chromosomes apart
½ of each chromosome (called chromotid) moves to each daughter cell

20. Anaphase Plant Cell Animal Cell
Photographs from:

21. Telophase The cytoplasm divides
Plant Cell
DNA spreads out
2 nuclei form
New cell wall forms between to nuclei to form the 2 new daughter cells
Animal Cell
DNA spreads out
2 nuclei form
Cell wall pinches in to form the 2 new daughter cells

22. Telophase Plant Cell Animal Cell
Photographs from:

23. Mitosis Animation

24. Animal Mitosis -- Review
Interphase                                                             
Prophase                                                             
Metaphase                                                             
Anaphase                                                             
Telophase                                                             

25. Plant Mitosis -- Review
Interphase                                                             
Prophase                                                             
Metaphase                                                             
Anaphase                                                             
Telophase                                                             

27. MEIOSIS

28. One parent cell produces four daughter cells.
Meiosis
Meiosis is the type of cell division by which sex cells (eggs and sperm) are produced.
One parent cell produces four daughter cells.
Daughter cells have half the number of chromosomes found in the original parent cell

29. During meiosis, DNA replicates once, but the nucleus divides twice.

30. Four stages can be described for each division of the nucleus.
Meiosis
Four stages can be described for each division of the nucleus.

31. First division of meiosis
Meiosis I
First division of meiosis

32. First Division of Meiosis
Prophase 1: Homologous chromosomes pair up and crossing over occurs. Crossing over allows for Variation
Metaphase 1: Homologous Chromosomes align at the center of the cell.
Anaphase 1: Homologous Chromosome pairs separate and go to opposite sides of the cell.
Telophase 1: Two daughter cells are formed with each daughter containing only one chromosome of the Homologous chromosome pair.

33. Prophase I

34. Prophase I

35. Metaphase I

36. Telophase I

37. Second Division of Meiosis

38. Second Division of Meiosis
Prophase 2: DNA does not replicate. No homologous pairs and no crossing over. This looks just like the prophase in Mitosis.
Metaphase 2: Chromosomes line up at the center of the cell
Anaphase 2: Sister chromatids move separately to each pole.
Telophase 2: Cell division is complete.
Four haploid daughter cells are formed.

39. Prophase II

40. Metaphase II

41. Telophase II

42. Meiosis

43. Meiosis Animation

44. Differences in Mitosis & Meiosis
Asexual
Cell divides once
Two daughter cells
Makes body cells (for growth and repair)
Genetic information is identical (2 sets of chromosomes = diploid)
Meiosis
Sexual
Cell divides twice
Four daughter cells
Makes gametes (sex cells)
Genetic information is different (there is 1/2 as much…1 set of chromosomes [haploid] instead of 2)

45. Comparison Animation