1. CHAPTER 8 REVIEW “Sex in the Cell City”

2. #1 Contrast asexual and sexual reproduction: ASEXUAL 1 parent Forms identical cells Forms 2 daughter cells SEXUAL 2 parents Forms different cells Forms 4 daughter cells

3. Compare: Chromatin, Chromosomes, Chromatids

4. ANSWER ALL ARE DNA + PROTEIN Chromatin – loose in interphase Chromosomes – dense and coiled in mitosis- single strands Chromatid – paired with sister chromatid –very coiled

5. 2. (cont) What are nucleosomes and histones? Nucleosome: Subunit of chromatin composed of a short length of DNA wrapped around a core of histone proteins.

6. DNA Coiling Animation

7. #3 What do you call asexual reproduction in prokaryotes? Binary fission What do you call asexual reproduction in eukaryotes? mitosis

8. Asexual and Sexual Repro How do the chromosome numbers compare before and after reproduction in each? EXAMPLE: If the original cell had 20 chromosomes, how many chromosomes would each cell have after each type of reproduction?

9. Start with 20…ANSWER Sexual Reproduction -resulting cells have half the number of chromosomes (EXAMPLE: 10 chromosomes) Asexual Reproduction -resulting cells have the identical number of chromosomes (EXAMPLE: 20 chromosomes)

10. #4 Contrast DNA in prokaryotes and eukaryotes Shape Size complexity

11. ANSWER #4 Chromosomes differ in… PROKARYOTES Circular Smaller (3,000 genes in bacterium) simpler EUKARYOTES Long strands Larger ( 100,000 genes in humans) More complex

12. #4 Compare the number of genes: Humans to bacteria ANSWER: 100,000 to 3,000

13. 5. Put in correct order Telophase Anaphase Metaphase prophase

14. 5. ANSWER PMAT –Prophase –Metaphase –Anaphase –Telophase

15. 6. How does nuclear membrane change? In prophase In telophase

16. 6. ANSWER Dissolves in prophase Reforms in telophase

17. 7. What is…? cytokinesis

18. 7. ANSWER Division of the cytoplasm

19. 8. How is cytokinesis different in… PLANT CELLS ANIMAL CELLS

20. 8. ANSWER PLANT CELLS Form cell plate ANIMAL CELLS Form a cleavage furrow by pinching in the cytoplasm

21. 8. (continued) Define: Cell plate Cleavage furrow

22. 8. ANSWER Cell plate In plant cells the cell wall will form Cleavage Furrow Pinching of the cytoplasm by actin pulling like a drawstring

23. 9. What goes on in each? G 1 S G 2

24. ANSWER G 1 grows in size, increases organelles S DNA synthesis (replicates) G 2 makes centrioles for cell division + growth

25. What is the purpose of… Mitosis? A. make bigger cells B. make exact copies of cells in two daughter cells C. make copies of cells with twice the number of chromosomes D. decrease the number of cells

26. ANSWER B. make exact copies of cells in two daughter cells

27. #25 Who determines the sex of the child? Female donates only X’s (XX) Male donates X or Y IF daughter XX IF son XY SO FATHER DETERMINES THE SEX OF THE CHILD

28. 10. Locate Chromatids Centromeres Asters Centrioles spindles

29. 10. ANSWER Chromatids Centromeres asters Spindles centrioles

30. 11. What makes the… Chromatids move to the poles (centrioles)?

31. 11. ANSWER centromeres attach to spindles that shorten toward the centrioles

32. 12. What is the name of… The protein that signals each phase of the cell cycle to start? cyclins

33. 13. What body cells... Divide a lot? Not at all after formed?

34. 13. ANSWER Divide a lot skin blood digestive tract Don’t divide after formed nerve muscle brain

35. 13. How are cancer cells... Abnormal in the cell cycle?

36. ANSWER Do not have a properly functioning cell cycle control system- grow uncontrollably

37. 14. Name the Phase of Mitosis Chromatin thickens nuclear envelope disappears nuclear envelope reforms Prophase prophase telophase

38. 14. Name the Phase of Mitosis Centrioles move to the opposite poles spindle fibers form cell plate forms Prophase prophase telophase

39. 14. Name the Phase of Mitosis Chromosomes line up at the equator cytoplasm divides Metaphase cytokinesis

40. 14 nucleoli break down Nucleoli reform Prophase telophase

41. 14. Identify the phase anaphase

42. 14. Identify the Phase of Mitosis prophase

43. 14. Identify the Phase of Mitosis telophase

44. 14. Identify the Phase of Mitosis Interphase

45. 14. Identify the Phase of Mitosis prophase

46. 14. Identify the Phase Metaphase

48. Essay #1 (cont)

49. #2 Why would the study of cyclins be helpful in the research of cancer? A. Cyclins are proteins that regulate the cell cycle. B. Their levels rise to activate checkpoints in the cell cycle and levels fall to end the part of the cycle.

50. #2 Essay (continued) C. p53 acts to check and repair DNA. IF there is a problem, it will stop the cell cycle. If it is malfunctioning, it is one of the greatest causes of cancer. D. Analogy: Roman soldiers building camp, conquering town, tearing down camp and moving on to another town.

53. #4 What would cause greater damage? Gain of an autosome. There is more vital information on the autosomes. The Y chromosome only determines the testes determining factor. A. Gain of Autosome: Trisomy 21-Down Syndrome, mental retardation, short, respiratory problems, sluggish muscles

54. Gain of a sex chromosome: XXY-Klinefelters’s Small testes (sterile) Soft breasts Feminine features Normal intelligence

55. OR Loss of a chromosome – Turner Syndrome Underdeveloped ovaries (sterile) Web between head and shoulders Short stature Normal intelligence

60. If given the diploid number, what is the haploid number? Diploid 40 24 16 Haploid 20 12 8

66. #28 What are gametes? A. autosomes B. female chromosomes C. sex cells D. daughter cells ANSWER: Gametes are sex cells. For Human they are sperm (male) and egg (female)