THE CELL CYCLE WORKSHEET Name: _________________________________ Date: __________ Per: ___ A) The diagram below shows six cells in various phases of the cell cycle. Note the cells are not arranged in the order in which the cell cycle occurs. Use the diagram to answer questions 1-11. ________ 1. Cells A & F show an early and a late stage of the same phase of the cell cycle. What phase is it? ________ 2. Which cell is in metaphase? ________3. Which cell is in the first phase of M phase (mitosis)? ________4. List the diagrams in order from first to last in the cell cycle. 5. In cell A, what structure is labeled X? 6. Are the cells depicted plant or animal cells? Explain your answer. a) If it were the other type of cell what would be different in the diagrams? 7. What is the longest phase of the cell cycle? 8. Why is mitosis important? 9. Predict what would happen if an individual had faulty spindle fibers. 10. Predict what would happen if cytokinesis was skipped. 11. How does interphase fit into this cell cycle organization listed above? 12. Sketch and label replicated chromosomes B) Answer the following questions: 1. What is meant by the concept that cells go through a cell cycle? 2. Do all cells go through the cell cycle at the same rate or at the same frequency? Explain. 3. What is meant by the G0 phase. 4. What is the significance of cells that are permanently in G0 phase? 5. Label the diagram of the cell cycle. C) Below is a list of the phases of the cell cycle. Write a brief description of what occurs in each phase. a. G1 b. S c. G2 d. M e. C f.Describe the two irreversible points in the cell cycle. g. What is the G1/S checkpoint and where does it fit into the cell cycle? h. What cell conditions are being monitored at the G1/S checkpoint? i. What is the G2/M checkpoint and where does it fit into the cell cycle? j. What cell conditions are being monitored at the G2/M checkpoint? k. What is the spindle checkpoint and where does it fit into the cell cycle? l. What cell conditions are being monitored at the spindle checkpoint? m. Why is the regulation of the cell cycle critical to normal function in the multicellular organism? D) For each of the following, takes notes about what type of molecule they are and their role in the cell cycle. a. Cdk’s b. cyclins c. growth factors d. PDGF e. MPF f. Describe a model for an external signal for growth. E) Answer the following: 1. What is the relationship between cancer and mitosis? 2. What is the role of the p53 gene? 3. What are proto-oncogenes? 4. What are tumor suppressor genes? 5. What evidence is there that regulation is chemical in nature?