Nucleolus is formed from

Options

A. Nucleus
B. Nuclear sap
C. Sat chromosome
D. Giant chromosome

Answer

To answer the question "Nucleolus is formed from," we will analyze the options provided and understand the formation of the nucleolus step by step.

### Step-by-Step Solution:

1. **Understanding the Nucleolus**:
- The nucleolus is a small, dense structure found within the nucleus of a cell. It is primarily involved in the synthesis of ribosomal RNA (rRNA) and the assembly of ribosomes.

2. **Identifying the Options**:
- A. Nucleus
- B. Nucleus sat
- C. Sat chromosomes
- D. Joint chromosome

3. **Analyzing the Options**:
- **Option A (Nucleus)**: While the nucleolus is located within the nucleus, it is not formed directly from the nucleus itself.
- **Option B (Nucleus sat)**: This term is not commonly used in cell biology and does not accurately describe any cellular component related to the nucleolus.
- **Option C (Sat chromosomes)**: Satellite chromosomes, which have secondary constrictions, are associated with nucleolar organizing regions. These regions are crucial for the formation of the nucleolus.
- **Option D (Joint chromosome)**: This term is also not standard in cell biology and does not relate to the formation of the nucleolus.

4. **Conclusion**:
- Based on the analysis, the correct answer is **Option C: Sat chromosomes**. The nucleolus is formed from the nucleolar organizing regions located on satellite chromosomes.

### Final Answer:
**C. Sat chromosomes**