Which of the following is a phase of mitosis?

• A. G1 phase
• B. Prophase
• C. Cytokinesis
• D. S phase

Answer: (B)

Verified step by step guidance

1. Understand that mitosis is the process of cell division where a single cell divides into two identical daughter cells. It consists of specific phases: prophase, metaphase, anaphase, and telophase.
2. Recognize that the G1 phase and S phase are part of the cell cycle but occur during interphase, which is the preparatory phase before mitosis begins. These are not phases of mitosis.
3. Clarify that cytokinesis is the process of dividing the cytoplasm and occurs after mitosis, but it is not considered a phase of mitosis itself.
4. Identify prophase as the first phase of mitosis, where chromatin condenses into visible chromosomes, the nuclear envelope begins to break down, and spindle fibers start to form.
5. Conclude that among the options provided, prophase is the correct answer as it is a phase of mitosis.