rRNA is synthesised in

Options

A. Nucleolus
B. Golgi body
C. Cytoplasm
D. Nucleoplasm

Answer

**Step-by-Step Solution:**

1. **Understanding rRNA**: Ribosomal RNA (rRNA) is a type of RNA that is a key component of ribosomes, which are the cellular structures responsible for protein synthesis.

2. **Identifying the Site of Synthesis**: The question asks where rRNA is synthesized. The primary site for rRNA synthesis in eukaryotic cells is the nucleolus.

3. **Role of the Nucleolus**: The nucleolus is a dense, darkly stained structure within the nucleus of a cell. It is associated with the chromatin and is specifically involved in the production of ribosomal RNA.

4. **Nucleolar Organizing Regions (NOR)**: The nucleolus is formed around specific chromosomal regions known as nucleolar organizing regions (NORs), which contain the genes for rRNA.

5. **Components of the Nucleolus**: The nucleolus has several parts: amorphous, fibrillar, granular, and chromatin. The fibrillar and granular components are primarily made up of RNA and proteins, contributing to the synthesis of rRNA.

6. **Conclusion**: Since the nucleolus is the site where ribosomal RNA is synthesized, the correct answer to the question is the nucleolus.

**Final Answer**: rRNA is synthesized in the nucleolus.

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