In a cell, which of the following is the active site of Ribosomal RNA synthesis?
- ((a))
DNA
- ((b))
Nucleoplasm
- ((c))
Nucleus
- ((d))
Nucleolus
Show Answer
Nucleolus
The correct answer is Nucleolus.

Key Points
- The nucleolus is a dense, spherical structure within the nucleus of a cell and is the primary site for ribosomal RNA (rRNA) synthesis.
- rRNA is an essential component of ribosomes, which are responsible for protein synthesis in cells.
- In the nucleolus, rRNA genes are transcribed, and rRNA is processed and assembled with ribosomal proteins to form ribosomal subunits.
- The nucleolus also plays a key role in regulating cellular stress responses and maintaining genomic stability.
- The size and activity of the nucleolus are directly proportional to the protein synthesis demands of the cell, making it more prominent in cells with high protein production.

Additional Information
- DNA:
- DNA (Deoxyribonucleic Acid) is the molecule that carries genetic information in all living organisms and many viruses.
- It serves as the template for the synthesis of RNA during transcription but is not directly involved in ribosomal RNA synthesis.
- In eukaryotic cells, rRNA is transcribed from specific regions of DNA known as rRNA gene clusters, which are located on multiple chromosomes.
- Nucleoplasm:
- The nucleoplasm, also known as nuclear sap, is the semi-fluid substance that fills the nuclear space within the nuclear membrane.
- It serves as a medium for the diffusion of ions, molecules, and enzymes required for nuclear processes like transcription, replication, and RNA transport.
- However, the nucleoplasm itself is not directly involved in rRNA synthesis.
- Nucleus:
- The nucleus is a membrane-bound organelle in eukaryotic cells that houses the genetic material (DNA).
- It is the control center for cellular activities such as transcription, replication, and RNA processing.
- While the nucleus contains the nucleolus, which is responsible for rRNA synthesis, the nucleus as a whole is not specifically the active site for rRNA synthesis.

















