Download Chap. 10 Notes Review Key

Chap. 10 Mitosis Notes Review
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Name ________________________
1. What is the purpose of mitosis? _____growth, development and cell repair_____ (1 pt)
2. Compare G1 of interphase to G2 of interphase.
G1 – cell, grows, does its job and prepares for mitosis. G2 – Cell continues to grow, duplicates the
organelles, creates spindle fibers (2 pts)
3. Describe what happens in prophase.
Chromatin thicken and become chromosomes, nucleolus and nuclear membrane disappears, asters
form and move to opposite sides of the cell, spindle apparatus forms. (3 pts)
4. What is congression?
The jerky movement of the chromosomes as the spindle fibers move them toward the metaphase plate.
(1 pt)
When does congression happen? ___Prometaphase_ (1 pt)
5. Describe what happens during anaphase.
The cohesion proteins that make up the centromere break down so the sister chromatid separate.
Spindle fibers shorten and the poles move apart causing the chromatid to move to opposite sides of the
cell. (3 pts)
6. Compare the process of cytokinesis in animals to cytokinesis in plants.
Cytokinesis in animals – the protein filaments that stretch across the cell shorten, creating the
cleavage furrow. The furrow deepens and the cells pull apart until they separate.
Cytokinesis in plants – the cell plate grows across the cell, gradually thickening. When it’s the proper
thickness, the cells separate. 4 pts)
7. What is cell apoptosis? Why would the cell do this?
Programed cell death. When errors have occurred in DNA replication or replication of a new cell that
are too extensive to correct, the cell causes the incorrectly made cell to die so that it can be
replaced with one that is correctly made. (3 pts)
8. Why do cell cycles vary in length?
Each species spends a different amount of time in G1 and G0 of interphase. (1 pt)
Why do most cells spend their time in this phase?
This is when the cell does its job. (2 pts)
9. Describe what happens during prometaphase and metaphase.
During prometaphase – spindle fibers grow out from the asters and attach to the chromosomes’
kinetochores. The chromosomes are moved toward the metaphase plate by congression.
During metaphase - the chromosomes are lined up along the metaphase plate. The centromeres are
lined up on the plate to ensure that the chromosomes are divided properly. (4 pts)
10. Explain the consequences of errors in metaphase.
When the spindle fibers shorten during anaphase, the chromatid will be separately unevenly. This
means that one cell will have too much information while the other has too little._(3 pts)
11. Compare what happens during Anaphase A with what happens during Anaphase B. (4 pts)
Anaphase A – the spindle fibers shorten, pulling the sister chromatid toward the poles.
Anaphase B – the poles begin to move away from each other, making the cell a peanut shape, again
moving the chromatid toward the poles.
Vocabulary: (1 pt each)
12. Centromere ____cohesion protein that holds sister chromatid together___________
13. Kinetochore _____proteins on the sides of the chromosome where the spindle fibers attach___
14. Sister chromatid ___the original chromosome and its duplicate_______
15. Aster ______a centriole and the spindle fibers that come out from it_______
16. Spindle fiber __a microtubule that grows out from the centriole, attaches to the kinetochore and moves
a chromosome during mitosis_______
17. Spindle apparatus ___a group of spindle fibers that grow out of the asters and stretch across the cell
during Prophase.
18. Cleavage furrow ___the indention between the original and newly created cell caused by shrinking
protein fibers. The cleavage furrow will eventually deepen enough to separate the
cells.
19. Metaphase plate ____the imaginary line the divided the cell in half. The chromosomes will line up here
during metaphase.____