1. Mitosis & Meiosis Unit #7

2. 1. What is condensed and coiled up DNA called? chromosomes

3. 2. What does the DNA wrap around? histones

4. 3. One copy of the DNA is called? chromatids

5. 4. When the two chromatids are put together, they produce a ________. chromosome

6. 5. What holds the chromatids together? centromere

7. 6. What is the segment of DNA that codes for a trait? gene

8. 7. In a human, number of individual chromosomes ____ Number of pairs of chromosomes __ 46 23

9. 8. How many chromosomes are contributed by the mother’s gamete? ____ Father’s gamete? ____ Total for the new zygote? ____ 23 46

10. 9. Allele combinations for normal female- ____ Normal male- ____ XX XY

11. 10. In a human, chromosome pairs 1-22 are _________ chromosomes. autosome

12. 11. In a human, chromosome pair #23 are ___ chromosomes. In a female they are __________(specific type) and in a male they are ______________(specific type). Sex egg gametes Sperm gametes

13. 12. Homologous chromosomes are autosome pairs that are the same ____, _____and carry the _______for the same trait. Size shape information

14. 13. Diploid cells which are _____________ (type) cells have ___ (number) individual chromosomes and __(number) 0f pairs. body/somatic body 46 23

15. 14. Haploid cells which are __________(type) cells have ____ (number) individual chromosomes and ____ (number) of pairs. sex/gametes 23 0

16. 15. Mitosis occurs in ___________ cells and meiosis occurs in _______ cells. body/somatic Sex

17. 16. What are the 4 reasons for cells to divide? -replace dead/old cells -repair existing cells -for growth of the organism -to maintain healthy cell size

18. 17. How long is Interphase? ~ 90% of cell life

19. 18. Do all cells leave Interphase? Give an example No, like the nerve cell stays in G0

20. 19. What happens in G1 part of Interphase? Cell grows and makes centrioles/organelles

21. 20. What is replicated in the S phase? DNA

22. 21. What happens in G2 part of Interphase? Final preparation for cell division

23. 22. What are the 3 main events in prophase? –-nuclear membrane & nucleolus fad and disappear –-centrioles appear & move to opposite ends releasing spindle fibers –-chromosomes form

24. 23. What 2 events in metaphase? -Chromosomes line up in the middle (equator) -Spindle fibers attach to centromeres

25. 24. What are the 3 main events in anaphase? -Centromeres split in half -Chromosomes split/separate into chromatids -Centrioles pull in spindle fibers & chromatids to opposite ends

26. 25. What are the 3 main events in telophase? -Centrioles & spindle fibers fade and disappear -nuclear membrane reappears and forms around chromatids -cells stretches out

27. 26. What happens in cytokinesis? Splitting of the cytoplasm and cell membranes into 2 new cells

28. 27. What divides the plant cell in cytokinesis? Cell plate

29. 28. What divides the animal cell in cytokinesis? Cleavage furrow

30. 29.What are the 2 events that are the same in Prophase I to mitosis prophase? -centrioles & spindle fibers appear -nuclear membrane & nucleolus disappear

31. 29. cont.The one major difference that causes genetic diversity? Crossing over-exchange of genetic material between homologous chromosome pairs

32. 30. Draw crossing over.

33. 31.What is the event in metaphase I that is similar to metaphase in mitosis? Spindle fibers attach to the centromeres

34. 32.What is the event that causes genetic diversity in metaphase I? Lining up randomly

35. 33.What happens in anaphase I? Chromosmes separate to opposite sides (different than anaphase in mitosis because entire chromosomes not chromotids seperate)

36. 34.What 2 events happen in telophase1? (Underline which one is a temporary process) -nuclear membrane forms around chromosomes -Spindle fibers & centrioles disappear

37. 35.What happens after telophase that splits the cells? cytokinesis

38. 36.What is meiosis II very similar to? mitosis

39. 37.What are the 3 main differences between mitosis and meiosis II? -starts with 2 daughter cells not just one -ends with 4 non identical daughter cells not 2 identical daughter cells -each cell formed has only 23 chromosomes not 46 (haploid not diploid)

40. 38. Recopy your Venn diagram comparing mitosis to meiosis.

41. 39.Male meiosis also known as ____________ produces __(number) _____ (type) cells. spermatogenesis 4 sperm

42. 40.Female meiosis also known as _______ produces __(number) __________(type) cell. oogenesis 1 mature egg

43. 41.What two phases cause oogenesis to produce only one mature cell? –-cytoplasm splits unevenly in telophase I –-telophase II

44. 42. Why is it important to have a large egg cell? To develop an organism

45. 43. What is it called when offspring are produced from only 1 parent? Asexual reproduction

46. 44.What is it called when offspring are produced from the combination of gametes from 2 parents? Sexual reproduction

47. 45.What is the process of fusing sperm and egg? Fertilization

48. 46. What is the new cell called from the joining of sperm and egg? Zygote