Chapter 12: The Cell Cycle

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Teresa Wells
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1 Name Perid Chapter 12: The Cell Cycle Overview 1. What are the three key rles f cell divisin? State each rle, and give an example. 2. What is meant by the cell cycle? Cncept 12.1 Mst cell divisin results ht genetically identical daughter cells 3. What is the meaning f genme? 4. Hw many chrmsmes are in a human smatic cell? 5. Name tw types f smatic cells in yur bdy. 6. What is a gamete? 7. Name the tw types f gametes. 8. Hw many chrmsmes are present in a human gamete? 9. Define chrmatin. 10. Think carefully, nw. Hw many DNA mlecules are in each f yur smatic cells? 72-

2 11. Yu are ging t have t learn the difference between several similar-sunding terms. The fllwing sketch that lks like an X represents a replicated chrmsme that has tw sister chrmatids. The narrw "waist" represents the lcatin f the centrmere. Students ften get all these terms cnfused, s take time nw t label the indicated areas f the figure and then define each f the terms belw. chrmsme chrmatid centrmere chrmatin 12. Study Figure 12.5 in yur text. Label the fllwing figure, and summarize what ccurs at the DNA level in each stage. \ / d.fÿ.\. j/ nzj 13. What is mitsis? Hw is it different frm cytkinesis? 14. What ccurs in meisis? Hw is the chrmsme number f daughter cells different?

3 15. Select either mitsis r meisis t answer the fllwing questins. By what prcess are the damaged cells in a wund replaced? By what prcess are eggs frmed? By what prcess des a zygte develp int a multicellular rganism? In which prcess are identical daughter cells prduced? Which prcess reduces the chrmsme number f daughter cells? 16. Dn't skip the Cncept Check Questins! They are a gd way t verify yur understanding. Here is a variatin f questin 3: A hedgehg has 90 chrmsmes in its smatic cells. a. Hw many chrmsmes did the hedgehg inherit frm each parent? b. Hw many chrmsmes are in each f the hedgehg's gametes? c. Hw many chrmsmes will be in each smatic cell f the hedgehg's ffspring? Cncept 12.2 The mittic phase alternates with interphase in the cell ÿtcle 17. Label each f the parts f the cell cycle listed belw, and give a brief explanatin f what happens in each phase. G1 S G2 M 18. What are the cmpnents f the mittic spindle? What is the surce f these cmpnents? 19. In animal cells, the assembly f spindle micrtubules starts at the centrsme. What is anther name fr the centrsme? 74-

4 20. Sketch and label a centrsme with tw centriles. 21. What are the cmpnents f the mittic spindle? 22. Describe what happens t the centrsme during interphase and then prphase. 23. What is a kinetchre? Read yur text carefully, and then make a labeled sketch that shws a replicated chrmsme with tw kinetechres and sme attached spindle fibers. Figure 12.8 in yur text may help. 24. Yu will need t spend sme serius time with Figure 12.7 in yur text. Use it t help yu label this figure. Label each phase by name; then label the smaller structures. Finally, make tw r three summary statements that indicate imprtant features t nte abut the phase. Phase Imprtant Features f Phase d Uÿ = rÿ ID eq +,a az eÿ0 1 c) 75-

5 Phase Imprtant Features f Phase 25. Explain the difference between kinetchre and nnkinetechre micrtubules. What is the functin f each? 26. At which end d kinetchre micrtubules shrten during anaphase? Explain the Inquiry Figure that supprts where this shrtening ccurs. 27. Describe cytkinesis in an animal cell. Use a labeled sketch that shws the cleavage furrw. 28. Describe cytkinesis in a plant cell. Use a labeled sketch that shws the cellplate. 29. Hw is the cell plate frmed? What is the surce f the material fr the cell plate? L) 30. Prkaryte reprductin des nt invlve mitsis, but instead ccurs by binary fissin. This prcess invlves an rigin f replicatin. Describe binary fissin. 31. Ntice that nw yu are learning a number f differences between prkarytic and eukarytic cells. Besides the fact that prkarytes lack a membrane-bunded nucleus, describe the fllwing differences: Mde f reprductin? Number f chrmsmes? Shape f the bacterial chrmsme? 76-

6 Cncept 12.3 The eukarytic cell ÿ3,'cle is regulated by a mlecular cntrl system 32. What cntrls the cell cycle? Study the Inquiry Figure in yur text t help yu answer this questin. 33. What is a cell cycle checkpint? 34. Summarize what happens at each checkpint. Yu may add t this chart as yu study this sectin. a1 G2 M 35. What is the GO phase? Describe this phase. 36. What is a prtein kinase? 37. Kinases drive the cell cycle, but they must be activated by attachment f a d 38. The activity f cyclin-dependent kinases (CDks) rises and falls. Why? 39. What des MPF trigger? What are sme specific activities that it triggers? ID 40. What happens if all the chrmsme kinetchres are nt attached t spindle fibers? When this ccurs, which checkpint is nt passed? ('4 41. What are grwth factrs? Hw des platelet-derived grwth factr (PDGF) stimulate fibrblast divisin? I 42. Cancer cells exhibit different behavirs than nrmal cells. Here are tw nrmal behavirs they n lnger shw. Explain each behavir. density-dependent inhibitin anchrage dependence

Cancer cells als shw lss f cell cycle cntrls and may divide withut being checked. The stry f HeLa cells is wrth nting. What is their surce? Hw ld are they?

7 Cancer cells als shw lss f cell cycle cntrls and may divide withut being checked. The stry f HeLa cells is wrth nting. What is their surce? Hw ld are they? Nte that, unlike nrmal cells, HeLa cells are immrtal! 44. What is transfrmatin? What is metastasis? 45. Distinguish between a benign tumr and a malignant tumr. 46. List tw specific cancer treatments, and tell hw each treatment wrks. 47. In the fllwing light micrgraph f dividing cells near the tip f an nin rt, identify a cell in each f the fllwing stages: prphase, prmetaphase, metaphase, anaphase, and telphase. eo O O IO O O Oq Test Yur Understanding Answers Nw yu shuld be ready t test yur knwledge. Place yur answers here: , 7. (abve)

The Cell Cycle & Cellular Division

The Cell Cycle & Cellular Divisin Name: Perid: Date: I. Cell Divisin: All are derived frm preexisting cells (Cell Thery) is the prcess by which cells prduce new cells Cells grw in number, NOT in Smaller