Question

Ribosomal RNA is actively synthesized in

• A. Lysosomes
• B. Nucleolus
• C. Nucleoplasm
• D. Ribosomes

Answer 1

The Correct Option is B

To determine where ribosomal RNA (rRNA) is actively synthesized, we need to understand the function and location of each given option related to cellular structures:

1. Lysosomes: These are membrane-bound organelles that contain enzymes for breaking down waste materials and cellular debris. They are not involved in RNA synthesis.
2. Nucleolus: The nucleolus is a prominent sub-structure within the nucleus of eukaryotic cells, primarily known for its role in the synthesis and assembly of ribosomes. Here, rRNA is transcribed and assembled with proteins to form the subunits of ribosomes. Therefore, this is the location where rRNA synthesis occurs actively.
3. Nucleoplasm: This is the gel-like substance within the nucleus where the chromatin and the nucleolus are found, but it does not directly participate in rRNA synthesis.
4. Ribosomes: These are the cellular components where protein synthesis takes place. Ribosomes are assembled from rRNA and proteins but do not engage in synthesizing rRNA themselves.

Based on this analysis, the correct answer is Nucleolus because it is the site where rRNA is synthesized and ribosome assembly is initiated.