Educational worksheet on the cell cycle, featuring a matching section and a diagram illustrating various stages of mitosis.

Matching Section: Match the Term to the Description

The cell cycle involves several phases, including interphase, prophase, metaphase, anaphase, and telophase. Each phase has distinct characteristics. Let's match the terms to their descriptions:

#### Matching Answers:
1. The sister chromatids are moving apart.
- D. Anaphase
- During anaphase, the sister chromatids separate and move toward opposite poles of the cell.

2. The nucleolus begins to fade from view.
- B. Prophase
- In prophase, the nucleolus starts to disappear as the chromatin condenses into chromosomes.

3. A new nuclear membrane is forming around the chromosomes.
- E. Telophase
- During telophase, a new nuclear membrane forms around each set of chromosomes, marking the end of mitosis.

4. The cytoplasm of the cell is being divided.
- E. Telophase (or cytokinesis)
- Cytokinesis, which occurs during or after telophase, divides the cytoplasm into two daughter cells.

5. The chromosomes become invisible.
- A. Interphase
- During interphase, the chromosomes are not visible because they exist as loosely coiled chromatin.

6. The chromosomes are located at the equator of the cell.
- C. Metaphase
- In metaphase, the chromosomes align at the cell's equatorial plate (metaphase plate).

7. The nuclear membrane begins to fade from view.
- B. Prophase
- The nuclear membrane breaks down in prophase, allowing the chromosomes to be visible.

8. The division (cleavage) furrow appears.
- E. Telophase (or cytokinesis)
- A cleavage furrow forms during cytokinesis in animal cells, dividing the cytoplasm.

9. The chromosomes are moving towards the poles of the cell.
- D. Anaphase
- During anaphase, the chromosomes move toward the spindle poles.

10. Chromatids line up along the equator.
- C. Metaphase
- Chromatids align at the metaphase plate during metaphase.

11. The spindle is formed.
- B. Prophase
- The spindle apparatus forms during prophase to help separate the chromosomes.

12. Chromosomes are not visible.
- A. Interphase
- Chromosomes are not visible during interphase because they are in the form of chromatin.

13. Cytokinesis is completed.
- E. Telophase
- Cytokinesis completes the division of the cell, often occurring during or after telophase.

14. The cell plate is completed.
- E. Telophase
- In plant cells, a cell plate forms during telophase, eventually developing into a new cell wall.

15. Chromosomes are replicated.
- A. Interphase
- DNA replication occurs during S phase of interphase, resulting in duplicated chromosomes.

16. The reverse of prophase.
- E. Telophase
- Telophase is often considered the reverse of prophase, as the nuclear membrane reforms and the chromosomes decondense.

17. The organization phase.
- A. Interphase
- Interphase is the phase where the cell grows, replicates its DNA, and prepares for mitosis.

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Diagram Analysis Questions

#### Question 1: Cells A & F show an early and a late stage of the same phase of the cell cycle. What phase is it?
- Answer: Prophase
- Cell A shows the beginning of prophase, where the chromatin is starting to condense into chromosomes, and the nuclear envelope is beginning to break down.
- Cell F shows a later stage of prophase, where the chromosomes are more condensed, and the nuclear envelope is almost completely dissolved.

#### Question 2: Which cell is in metaphase?
- Answer: Cell C
- In metaphase, the chromosomes align at the cell's equatorial plate. Cell C clearly shows this alignment.

#### Question 3: Which cell is in the first phase of M phase (mitosis)?
- Answer: Cell B
- The first phase of mitosis is prophase. Cell B shows chromosomes that have fully condensed, and the nuclear envelope is completely dissolved, indicating prophase.

#### Question 4: In cell A, what structure is labeled X?
- Answer: Nuclear Envelope
- Structure X in cell A is the nuclear envelope, which is beginning to break down during prophase.

#### Question 5: List the diagrams in order from first to last in the cell cycle.
- Answer: A → B → C → E → F → D
- A: Early prophase (chromatin condensing).
- B: Late prophase (chromosomes fully condensed, nuclear envelope dissolved).
- C: Metaphase (chromosomes aligned at the equator).
- E: Anaphase (sister chromatids separating).
- F: Telophase (nuclear envelope reforming, chromosomes decondensing).
- D: Interphase (chromosomes not visible, cell growth and preparation for mitosis).

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Final Answer:

1. Prophase
2. Cell C
3. Cell B
4. Nuclear Envelope
5. A → B → C → E → F → D

Boxed Final Answer:
\[
\boxed{\text{Prophase, Cell C, Cell B, Nuclear Envelope, A → B → C → E → F → D}}
\]