Question

Which organelle is the site of ribosome synthesis?
A) Mitochondria
B) Smooth Endoplasmic reticulum
C) Chloroplast
D) Golgi apparatus
E) Nucleolus

Answer 1

Hint:Ribosome is the organelle which is the site of protein synthesis. They are found freely in the cytoplasm of prokaryotic cells and remain attached to the rough endoplasmic reticulum in the eukaryotic cell.

Complete answer:
To solve this question, we must know about the ribosome synthesis.
The ribosome biosynthesis is a very complex process. The proteins required for the synthesis of ribosome is synthesised by the ribosome itself in the cytoplasm. It is then transported to the nucleus for further processing. In the nucleus the dense region called the nucleolus is present which is responsible for the packaging and assembly of the proteins and form ribosomes. After the assembly it is exported out to the cytoplasm.
Mitochondria- It is the organelle responsible for synthesis of ATP.
Smooth ER- It plays a role for the synthesis of hormones and lipids in the cell.
Chloroplast- It is the site of photosynthesis. It is present only in plant cells.
Golgi apparatus- It is responsible for the sorting assembly and transport of proteins.

Thus the correct answer is option (E). Nucleolus is the site of ribosome synthesis.

Note:Nucleolus is a special dense region in the eukaryotic cell. It is composed of RNA and protein. It plays a vital role in sensing cellular stress and assembling of ribosomes. In prokaryotic cells, the ribosome is synthesised in cytoplasm. The cell uses 60% of its energy in ribosome biosynthesis.