Educational worksheet for labeling mitosis phases and understanding cell division processes.

I will solve this worksheet on mitosis step by step, explaining each answer based on the provided diagrams and biological knowledge.

Part 1: Label the phases of Mitosis (Questions 11-15)

First, I need to identify the stages of mitosis shown in the five diagrams. The stages are typically Prophase, Metaphase, Anaphase, Telophase, and Cytokinesis (which often occurs alongside Telophase).

- Diagram 11: Shows a cell with a visible nucleus and nucleolus, but chromosomes are not yet condensed. This is Interphase.
- Diagram 12: Chromosomes are lined up at the equator (metaphase plate) of the cell. This is Metaphase.
- Diagram 13: Sister chromatids are being pulled apart to opposite poles. This is Anaphase.
- Diagram 14: Two nuclei are forming, and the cell is starting to pinch in the middle. This is Telophase.
- Diagram 15: Two separate daughter cells are formed. This represents the end of Cytokinesis.

So, the answers are:
11. Interphase
12. Metaphase
13. Anaphase
14. Telophase
15. Cytokinesis

---

Part 2: Complete the Table (Questions 16-22)

This table asks whether certain events occur during Interphase or Mitosis.

- 16. Cell growth occurs: This happens primarily during Interphase (specifically G1 and G2 phases). Yes for Interphase, No for Mitosis.
- 17. Nuclear division occurs: This is the definition of Mitosis. No for Interphase, Yes for Mitosis.
- 18. Chromosomes are finishing moving into separate daughter cells: This describes the end of Mitosis (Telophase). No for Interphase, Yes for Mitosis.
- 19. Chromosomes are duplicated: DNA replication happens during the S phase of Interphase. Yes for Interphase, No for Mitosis.
- 20. DNA synthesis occurs: Also happens during the S phase of Interphase. Yes for Interphase, No for Mitosis.
- 21. Where cells spend most of their life: Cells spend the majority of their time in Interphase, preparing for division. Yes for Interphase, No for Mitosis.
- 22. Mitochondria and other organelles are made: Organelle synthesis occurs during Interphase (G1 and G2). Yes for Interphase, No for Mitosis.

---

Part 3: Use the illustrations for questions 23-32

These questions refer to the six black-and-white diagrams labeled A through F.

#### Questions 23 & 24: Identify structures

- 23. In cell A, what is the structure labeled X?
- Cell A shows chromosomes condensing and spindle fibers beginning to form. Structure X points to one of these spindle fibers. These are called spindle fibers or microtubules.
- 24. In cell F, what is the structure labeled Y?
- Cell F shows chromosomes aligned at the metaphase plate. Structure Y points to one of the sister chromatids making up a chromosome. So, Y is a sister chromatid.

#### Question 25: Which cell is not in a phase of mitosis?

- 25. Which cell is not in a phase of mitosis?
- Cell D shows a cell with an intact nucleus and no visible chromosomes. This is Interphase, which is not technically a phase of mitosis (mitosis is nuclear division, while interphase is the preparatory stage). So, the answer is D.

#### Question 26: Phase where new nuclear membranes form

- 26. New nuclear membranes are forming in B. What is this phase called?
- Cell B shows two distinct nuclei forming at opposite poles, with chromosomes decondensing. This is Telophase.

#### Question 27: Sequence the diagrams chronologically

- 27. Sequence the six diagrams in chronological order from first to last.
- We need to arrange the cells from the start of mitosis to the end.
- D: Interphase (start)
- A: Prophase (chromosomes condense, spindle forms)
- F: Metaphase (chromosomes align at equator)
- E: Anaphase (sister chromatids separate)
- B: Telophase (nuclear envelopes reform)
- C: Cytokinesis (cell splits into two)
- So, the sequence is: D, A, F, E, B, C

#### Question 28: When do chromosomes move to the middle?

- 28. Chromosomes move to the middle of the cell during?
- This happens during Metaphase.

#### Question 29: When do sister chromatids separate?

- 29. When do the sister chromatids separate?
- They separate during Anaphase.

#### Question 30: When do chromosomes first become visible?

- 30. During which phase do chromosomes first become visible?
- Chromosomes become visible as distinct structures during Prophase.

#### Question 31: When does the cleavage furrow start forming?

- 31. During which phase does the cleavage furrow start forming on animal cells?
- The cleavage furrow begins to form during Telophase as the cell prepares to divide.

---

Final Answers:

Part 1:
11. Interphase
12. Metaphase
13. Anaphase
14. Telophase
15. Cytokinesis

Part 2:
16. Interphase: Yes, Mitosis: No
17. Interphase: No, Mitosis: Yes
18. Interphase: No, Mitosis: Yes
19. Interphase: Yes, Mitosis: No
20. Interphase: Yes, Mitosis: No
21. Interphase: Yes, Mitosis: No
22. Interphase: Yes, Mitosis: No

Part 3:
23. Spindle fiber (or microtubule)
24. Sister chromatid
25. D
26. Telophase
27. D, A, F, E, B, C
28. Metaphase
29. Anaphase
30. Prophase
31. Telophase