CELL CYCLE
1.
Name and briefly describe the three main stages of the cell cycle.
2.
How long does it take eukaryotic cells to complete the cell cycle?
3.
What is the purpose of interphase?
4.
Name and describe the three stages of interphase.
5.
What is chromatin?
6.
What is the name of the stage of the cell cycle immediately following interphase when the cell’s nuclear material
divides and separates into opposite end of the cell called?
7. Draw the cell at each phase of mitosis. Label the four parts of the cell using the letter given. Describe what is going on in
your own words.
Parts of the cell involved in mitosis
A
chromosomes
B
spindle fibers (apparatus)
C
centrioles
D
nuclear membrane
Phase
PROPHASE
METAPHASE
ANAPHASE
TELOPHASE
Diagram of cell (draw)
What is happening (own words)
8. Following telophase, what is the name of the step in which the cytoplasm divides?
9. Describe in your own words what is happening during this last step.
10. Is the following diagram a picture of an animal cell or a plant cell dividing? Explain how you know.
11. How many cells are created at the end of the cell cycle? How do these new cells compare to each other?
You observe the following cells while looking at a onion root tip under a microscope.
12. On the above diagram, circle and label one cell in each stage of the cell cycle (interphase, prophase, metaphase,
anaphase and telophase)
13. Using the diagram on the previous page, calculate the percent of cells in each phase of the cell cycle.
Percent of cells in phase =
Total number of cells in phase
----------------------------------------- x 100
Total number of cells counted
Stage of cell cycle
Interphase
# of cells
% of cells in each phase
Prophase
Metaphase
Anaphase
Telophase
Total # of cells
100%
14. It takes approximately 24 hours (1440 minutes) for onion root tip cells to complete the entire cell cycle. Calculate the
amount of time spent in each phase of the cell cycle.
Time in phase (minutes) =
Percent of cell in phase x 1440 minutes
-----------------------------------------------------100
15. Graph your above results (minutes spent in each stage). Make sure to include a title and labels.
16. Which phase of the cell cycle is not considered part of mitosis?
17. How can prophase be distinguished from interphase under a microscope?
18. Where do a cell’s chromosomes line up at during metaphase?
19. Which stage does a cell spend most of its time?
20. Which stage does a cell spend the least of its time?
21. Why is an onion root tip used to count the cells in the stages of the cell cycle?