Mitosis and the Cell Cycle Questions For animations of the stages of the cell cycle, visit: Johnkyrk.com - Mitosis 1. Arrange the following in order from smallest to largest (codon, chromatin, chromosome, gene, gene, nucleotide base) 2. In the following picture, label the sister chromatids, chromosome, and centromere. 2. In what way are the newly formed cells, which result from mitosis, similar to the mother cell? 3. Why is it necessary for DNA to replicate before mitosis begins?
AP BIOLOGY ACTIVITY 1.19 4. The picture below is of a cell in interphase, label any visual clue that would help you to identify a cell in this stage. 2. Interphase is made up of three distinct stages. Describe them below. Phase Phase Description G1 S G2 3. The picture below is of a cell in prophase (the first step of mitosis,) label any visual clue that would help you to identify a cell in this stage. 4. Briefly describe what happens in early prophase.
5. Below is a cell in prometaphase (a transition from prophase to metaphase,) label any visual clue that would help you to identify a cell in this stage. 6. Briefly describe what happens in prometaphase. 7. The picture below is of a cell in metaphase, label any visual clue that would help you to identify a cell in this stage. 8. Briefly describe what happens in metaphase.
AP BIOLOGY ACTIVITY 1.19 9. The picture below is of a cell in anaphase, label any visual clue that would help you to identify a cell in this stage (besides, you know, the arrow labeled anaphase ). 10. Briefly describe what happens in anaphase. 11. (p 181) Gary Borisy and his colleagues at the University of Wisconsin hypothesis that during anaphase, a chromosome is walked along a microtubule as a microtubule depolymerizes at is kinetochore end, releasing subunits. Describe or draw what that means, and then explain how their work supported it. 12. The picture below is of a cell in telophase, label any visual clue that would help you to identify a cell in this stage.
AP BIOLOGY ACTIVITY 1.19 13. Briefly describe what happens in telophase. 13. Identify the stage of mitosis in each of the following onion cells. 14. In the image below, label at least two cells in each stage of division, and two cells that are not dividing.
15. Go to the University of Arizona s Online Onion Root Tip Lab, follow the directions and total up the numbers of cells you identify in each stage. Interphase Prophase Metaphase Anaphase Telophase Total number of cells percent of cells 36 100 16. On average, it takes 24 hours for an onion root-tip cells to complete the cell cycle. Using this information, and your results above, calculate the amount of time spent in each phase of the cell cycle. Interphase Prophase Metaphase Anaphase Telophase Total Percent of Time Actual Time 100 1440 minute s 17. In class, grab a microscope and an onion root-tip slide. Take a look at four or five fields of view at high power and try to count how many of 100 cells are in each stage of the cell cycle. Do they match up to what you saw in the online activity? Interphase Prophase Metaphase Anaphase Telophase Total number of cells 100
18. What are the major differences between mitosis in animal cells and mitosis in plant cells? Animal Cell Mitosis Plant Cell Mitosis 19. Draw a picture, or describe with words how cytokinesis differs in plant and animal cells. 20. What directs the sequential events of the cell cycle? 21. Using the image below, explain the mechanical analogy of the cell cycle control system
22. What is the significance or importance of the checkpoints in the cell cycle? 23. For many cells, what seems to be the most important checkpoint? 24. What happens to the cell if it meets the requirements of this checkpoint? 25. What happens to the cell if it fails to meet the requirements of this checkpoint? 25. Explain how physical factors like density-dependent inhibition and anchorage dependence affect cell division.