Nucleolus contains

Options

A. Genetic insturctions
B. Ribsome assemble line
C. Protein synthesis machinery
D. Enzymes for polysaccharide formation.

Answer

**Step-by-Step Solution:**

1. **Understanding the Nucleolus**: The nucleolus is a prominent structure found within the nucleus of eukaryotic cells. It is not surrounded by a membrane and is primarily involved in the production and assembly of ribosomes.

2. **Composition of the Nucleolus**: The nucleolus contains various components, including proteins, ribonucleic acid (RNA), and some deoxyribonucleic acid (DNA). However, its primary constituents are proteins and RNA.

3. **Function of the Nucleolus**: The main function of the nucleolus is to synthesize ribosomal RNA (rRNA). This rRNA is essential for the formation of ribosomes, which are the cellular machinery responsible for protein synthesis.

4. **Identifying the Correct Option**: Among the options provided:
- A. Genetic instructions: This refers to DNA, which is not the primary role of the nucleolus.
- B. Ribosome assembly line: This accurately describes the nucleolus's function in synthesizing rRNA and assembling ribosomes.
- C. Protein synthesis machinery: While ribosomes are involved in protein synthesis, the nucleolus itself does not synthesize proteins.
- D. Enzymes for polysaccharide formation: This is unrelated to the nucleolus's function.

5. **Conclusion**: Based on the analysis, the correct answer is **B. Ribosome assembly line**, as the nucleolus is primarily responsible for the assembly of ribosomes through the synthesis of rRNA.

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