1. Today… Please go get your science notebooks Turn in any missing work that you have! Get an SSR (silent sustained reading) book

2. MITOSIS AND MEIOSIS Cell Division

3. Why do cells need to divide? Adult human bodies are made of ~40 TRILLION cells Make 70 BILLION new cells every day  Over 800,000 new cells every second Cells need to divide for...  Growth and development for organisms  Repair of damaged or old cells

4. Types of Reproduction Asexual Reproduction:  Single parent passes all its DNA to its offspring  Daughter cell is genetically IDENTICAL to parent Sexual Reproduction  Two parents form reproduction cells which fuse to form offspring during fertilization.  Offspring gets half of both parents DNA  Daughter cell is genetically DIFFERENT than parent cells

5. Types of Reproduction AsexualSexual Positives Negatives Repair Identical cells Quick Genetically varied offspring Species is more stable Organisms are all the same (disease can wipe out an entire population) Requires 2 parents More time consuming

6. Cell Type Reproduction Prokaryotic cells reproduce by binary fission  Asexual reproduction that produces identical daughter cells Eukaryotic cells reproduce by mitosis and meiosis

7. Type of Cell Division Mitosis: Process of asexual reproduction to produce somatic cells  Somatic cell = body cells  (skin, hair, liver, intestine, etc.) Somatic cells are called diploid cells because they contain two sets of chromosomes = 2N

8. Type of Cell Division Meiosis: Process of cell division to produce gamete cells to prepare organism for sexual reproduction  Gamete cell = sex cells  (sperm and egg) Gamete cells are called haploid cells because they contain one (or half) set of chromosomes = N

9. Type of Cell Division Fertilization is the union of gametes (egg and sperm) that restores the diploid number  Egg (N) + Sperm (N) = Diploid Zygote (2N)

10. DNA & Chromosomes Chromosomes are made of DNA, found in nucleus  Before a cell divides, DNA must first be copied so each daughter cell will have a copy

11. DNA & Chromosomes DNA will condense before a cell divides to form chromosomes  Chromosomes are only visible in a cell during cell division

12. DNA & Chromosomes Chromosomes contain BOTH copies of DNA  One copy of DNA will condense into a chromatid  Two copies of DNA will condense into identical chromatids = sister chromatids  Sister chromatids attach at a point called the centromere

13. Today… Grab you science notebooks, put any late/missing work in the turn in tray! Make sure you have your foldable/rubric from last class (if you were absent, check the Absent Folder) Bellwork: Put phases in order on desks (at the beginning of the class time)

14. The Cell Cycle Cells goes through phases or a cell cycle during their life before they divide to form daughter cells The Cell Cycle is made of 3 parts: 1. Interphase 2. Mitosis 3. Cytokinesis

15. Bellwork (11/14) What type of reproduction produces identical daughter cells? What is a somatic cell? How many sets of chromosomes do somatic cells have? What do we call these?

16. Bellwork 11/18 http://www.youtube.com/watch?v= L0k-enzoeOM https://www.youtube.com/watch?v= gwcwSZIfKlM Write 3 facts you learn in the video we will watch at the beginning of the hour!

17. Cell Cycle Foldable

18. Interphase Interphase is the longest part of a cell’s life  Cell is carrying out normal function  Cell will grow in size, copy it’s DNA, and makes more organelles all to prepare to divide

19. Mitosis Mitosis is the division of the nucleus and chromosomes/ DNA within it PMAT  Prophase  Metaphase  Anaphase  Telophase

20. Mitosis Prophase  DNA condenses into chromosomes  Nucleus dissolves  Spindle fibers start to form

21. Mitosis Metaphase  Spindle fibers move chromosomes to the middle of the cell

22. Mitosis Anaphase  Spindle fibers pull chromosomes apart by separating sister chromatids at their centromeres

23. Mitosis Telophase  Two nucleus starts to form  Chromosomes unwind back into DNA

24. Cytokinesis Cytokinesis: division of cytoplasm and cell to results in 2 daughter cells

25. Stages of Mitosis Lab

26. Bellwork (11/24) What are two reasons why an organism’s cells would go through mitosis? What is the result when a single cell reproduces by mitosis? a) Two cells with genetic material identical to the parent cell b) Two cells with half the genetic material of the parent cell c) Four cells with half the genetic material of the parent cell d) Four cells with genetic material identical to the parent cell What phase of mitosis has two nuclei found in the cell?

27. Bellwork (11/23) What type of cells are made in mitosis? What type of cells are made in meiosis What is a somatic cell? What happens during Interphase of the Cell Cycle?

28. Go get your science notebooks, please! Turn in any late/missing work Bell work:  Cell Division Summary Refresher AS A CLASS!

29. Mitosis Summary 1 parent diploid cell 2 daughter diploid cells (genetically identical to parent)

30. http://www.pbslearningmedia.org/asset/lsps07_int _celldivision/ http://www.pbslearningmedia.org/asset/lsps07_int _celldivision/

31. Mitosis Video https://www.youtube.com/watch?v=gwcwS ZIfKlM https://www.youtube.com/watch?v=gwcwS ZIfKlM

32. Meiosis Meiosis: cell division that produce haploid gametes (sperm and egg) cells  1 Diploid Parent Cell  4 Haploid Daughter Cells  Requires 2 divisions:  Meiosis 1  Meiosis 2

33. Meiosis Homologous chromosomes  Homologous = same information  Paired chromosomes that both carry a pair of “matching” genes  one from mom and one from dad

34. Meiosis Meiosis 1: separate homologous pairs  Interphase  Cell grows and copies DNA  Prophase 1  DNA  chromosomes  Nucleus dissolves  Crossing over between homologous chromosomes

35. Meiosis Crossing Over:  portions of the chromosomes are exchanged with homologous chromosomes – adds to genetic variety in offspring for sexual reproduction

36. Meiosis Meiosis 1: separate homologous pairs  Metaphase 1  Homologous chromosomes line up in the middle  Anaphase 1  Homologous chromosomes are pulled apart

37. Meiosis Meiosis 1: separate homologous pairs  Telophase 1  2 nuclei form  Cytokinesis  Cytoplasm and cell splits into 2 cells

38. Meiosis Meiosis 2: separate sister chromatids  Prophase 2  Nucleus dissolves  Metaphase 2  Chromosomes line up in the middle

39. Meiosis Meiosis 2: separate sister chromatids  Anaphase 2  Chromosomes are pulled apart  Telophase 2  2 nuclei form  Chromosomes  DNA  Cytokinesis  Each cell splits = 4 cells!

40. Meiosis 1 & 2

41. Meiosis Summary 1 parent diploid cell 4 daughter haploid cells (gametes)

42. Practice Questions An organism’s diploid number is 50. a. How many chromosomes would be found in a somatic cell of this organism? b. How many chromosomes would be found in a gamete of this organism?

43. Practice If an organism has a somatic cell with 20 chromosomes and it undergoes meiosis, how many chromosomes will the daughter cells have? If a organism’s skin cell has 106 chromosomes, it undergoes mitosis twice, how many chromosomes will each daughter cell have? How many daughter cells will there be total?

44. Practice If a gamete has 30 chromosomes, how many chromosome are in the intestine cell of this individual If a cell undergoes mitosis and the resulting cell has 30 chromosomes, how many did the original have?

45. Fertilization Meiosis  Fertilization  Mitosis & Development (N) (N + N) (2N) 46 23 meiosi s sperm egg fertilization mitosis development zygote 46

46. Differentiation All cells start like this...

47. Differentiation Become... Red blood cells

48. Differentiation Become... Cheek cells

49. Differentiation Become... Small intestine cells

50. Differentiation Become... Nerve cell

51. Differentiation Become... Muscle cell

52. Differentiation Become... Bone cell

53. Differentiation Differentiation: After fertilization (fusing of gametes), cells will divide and become specialized in specific functions – they become different cells!

54. Mitosis vs. Meiosis Mitosis  # of divisions  Parent Cell  Daughter Cell  Chromosome #  Crossing Over? Meiosis  # of divisions  Parent Cell  Daughter Cell  Chromosome #  Crossing Over?

55. Explain Booklets Explain Google Classroom

56. Types of Reproduction Sexual reproduction introduces genetic variation in species  Genetic recombination  Homologous chromosomes randomly align during metaphase  Crossing over  Mixing of genes across homologous chromosomes  Random fertilization  Which sperm will fertilize which egg?

57. Types of Reproduction AsexualSexual Positives Repair Identical cells Genetically varied offspring Species is more stable Negatives Organisms are all the same (disease can wipe out an entire population) Requires 2 parents More time consuming

58. Meiosis Video http://www.youtube.com/watch?v=toWK0fIyFlY

59. Meiosis WebQuest

60. Critical Reading

61. Mitosis vs Meiosis WebQuest

62. Bill Nye Video

63. Mitosis and Meiosis

64. Cell Division Venn Diagram