The following disappear at the end of prophase

Options

A. Nucleolus
B. Nuclear envelope
C. Golgi and ER
D. All

Answer

To answer the question "What disappears at the end of prophase?", we can break down the information step by step:

### Step-by-Step Solution:

1. **Understanding Prophase**: Prophase is the first stage of mitosis, which is the process of cell division. It is characterized by several key events that prepare the cell for division.

2. **Chromosome Condensation**: During prophase, the chromatin condenses into visible chromosomes. Each chromosome consists of two sister chromatids joined at the centromere.

3. **Formation of Spindle Fibers**: As prophase progresses, the mitotic spindle begins to form. This structure is crucial for the separation of chromosomes during later stages of mitosis.

4. **Disappearance of the Nucleolus**: One of the key events at the end of prophase is the disappearance of the nucleolus. The nucleolus is a dense region within the nucleus where ribosomal RNA is synthesized.

5. **Disappearance of the Nuclear Envelope**: Along with the nucleolus, the nuclear envelope, which surrounds the nucleus, also breaks down at the end of prophase. This allows the spindle fibers to access the chromosomes.

6. **Disappearance of Golgi Apparatus and Endoplasmic Reticulum**: Additionally, the Golgi apparatus and the endoplasmic reticulum (ER) also undergo disassembly during prophase. This is part of the cell's preparation for division, as these organelles will reform after mitosis.

7. **Conclusion**: Therefore, at the end of prophase, the following structures disappear:
- Nucleolus
- Nuclear envelope
- Golgi apparatus
- Endoplasmic reticulum

### Final Answer:
At the end of prophase, the nucleolus, nuclear envelope, Golgi apparatus, and endoplasmic reticulum disappear.

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