The Cell Cycle Worksheet answer key showing correct answers for matching terms to descriptions and filling in blanks related to mitosis phases.

The Cell Cycle Worksheet Solution and Explanation

#### Matching Section
The task is to match the term (A. Prophase, B. Interphase, C. Telophase, D. Metaphase, E. Anaphase) to the description provided.

1. The sister chromatids are moving apart.
- Answer: E (Anaphase)
- Explanation: During Anaphase, the sister chromatids separate and move toward opposite poles of the cell.

2. The nucleolus begins to fade from view.
- Answer: B (Interphase)
- Explanation: In Interphase, the nucleolus is visible, but as the cell prepares for mitosis, it begins to fade during Prophase.

3. A new nuclear membrane is forming around the chromosomes.
- Answer: C (Telophase)
- Explanation: During Telophase, a new nuclear membrane forms around the separated chromosomes in each daughter nucleus.

4. The cytoplasm of the cell is being divided.
- Answer: C (Telophase)
- Explanation: Cytoplasmic division (Cytokinesis) occurs during Telophase, completing the separation of the two daughter cells.

5. The chromosomes become invisible.
- Answer: C (Telophase)
- Explanation: After Telophase, the chromosomes decondense and become invisible as they return to chromatin form.

6. The chromosomes are located at the equator of the cell.
- Answer: D (Metaphase)
- Explanation: During Metaphase, the chromosomes align at the metaphase plate (equator) of the cell.

7. The nuclear membrane begins to fade from view.
- Answer: A (Prophase)
- Explanation: In Prophase, the nuclear membrane begins to break down, allowing the chromosomes to become visible.

8. The division (cleavage) furrow appears.
- Answer: C (Telophase)
- Explanation: The cleavage furrow is a indentation that forms during Cytokinesis, which occurs in Telophase.

9. The chromosomes are moving towards the poles of the cell.
- Answer: E (Anaphase)
- Explanation: During Anaphase, the chromosomes move toward the spindle poles due to the shortening of microtubules.

10. Chromatids line up along the equator.
- Answer: D (Metaphase)
- Explanation: In Metaphase, the chromatids align at the metaphase plate (equator).

11. The spindle is formed.
- Answer: A (Prophase)
- Explanation: The spindle apparatus forms during Prophase, with microtubules extending from the centrosomes.

12. Chromosomes are not visible.
- Answer: B (Interphase)
- Explanation: During Interphase, chromosomes are in their uncondensed form (chromatin) and are not visible under a microscope.

13. Cytokinesis is completed (as next cycle begins).
- Answer: B (Interphase)
- Explanation: After Cytokinesis, the cell enters Interphase, where it prepares for the next round of cell division.

14. The cell plate is completed.
- Answer: C (Telophase)
- Explanation: In plant cells, the cell plate forms during Telophase, eventually developing into the new cell wall.

15. Chromosomes are replicated.
- Answer: B (Interphase)
- Explanation: DNA replication occurs during S phase of Interphase.

16. The reverse of prophase.
- Answer: C (Telophase)
- Explanation: Telophase is essentially the reverse of Prophase, where the nuclear membrane reforms, chromosomes decondense, and the cell returns to its normal state.

17. The organization phase.
- Answer: B (Interphase)
- Explanation: Interphase is the "resting" or organizational phase of the cell cycle, where the cell grows and prepares for division.

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#### Fill in the Blank Section
The task is to fill in the blanks using the provided terms (A. Prophase, B. Interphase, C. Telophase, D. Metaphase, E. Anaphase, F. Centromere, G. Chromatid, H. Cytokinesis, I. Mitosis, J. Spindle fiber, K. Cell plate).

18. What phase are daughter cells in as a result of mitosis?
- Answer: B (Interphase)
- Explanation: After mitosis, the daughter cells enter Interphase, where they grow and prepare for the next cell division.

19. During what phase of mitosis do centromeres divide and the chromosomes move toward their respective poles?
- Answer: E (Anaphase)
- Explanation: In Anaphase, the centromeres split, and the sister chromatids move toward opposite poles.

20. What is the phase where chromatin condenses to form chromosomes?
- Answer: A (Prophase)
- Explanation: During Prophase, chromatin condenses into visible chromosomes.

21. What is the name of the structure that connects the two chromatids?
- Answer: F (Centromere)
- Explanation: The centromere is the region where the two sister chromatids are attached.

22. In a chromosome pair connected by a centromere, what is each individual chromosome called?
- Answer: G (Chromatid)
- Explanation: Each individual chromosome in a pair is called a chromatid.

23. What are the two parts of cell division?
- Answer: I, H (Mitosis, Cytokinesis)
- Explanation: Cell division consists of Mitosis (nuclear division) and Cytokinesis (cytoplasmic division).

24. What structure forms in prophase along which the chromosomes move?
- Answer: J (Spindle fiber)
- Explanation: Spindle fibers form during Prophase and guide the movement of chromosomes during mitosis.

25. Which phase of mitosis is characterized by the chromosomes lining up at the equator?
- Answer: D (Metaphase)
- Explanation: During Metaphase, the chromosomes align at the metaphase plate (equator).

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Final Answer Summary

- Matching Section:
1. E, 2. B, 3. C, 4. C, 5. C, 6. D, 7. A, 8. C, 9. E, 10. D, 11. A, 12. B, 13. B, 14. C, 15. B, 16. C, 17. B

- Fill in the Blank Section:
18. B, 19. E, 20. A, 21. F, 22. G, 23. I, H, 24. J, 25. D

Boxed Final Answer:
\[
\boxed{
\text{Matching: } E, B, C, C, C, D, A, C, E, D, A, B, B, C, B, C, B \\
\text{Fill in the Blank: } B, E, A, F, G, I, H, J, D
}
\]