Question

Which of the following ribosomes are involved in protein synthesis?

• A. Ribosomes which occur on the nuclear membrane and E.R
• B. Ribosomes of only cytosol
• C. Ribosomes of only nucleolus and cytosol
• D. Ribosomes of only mitochondria and cytosol

Answer 1

The correct option is A

Ribosomes which occur on the nuclear membrane and E.R

The correct option is A.

Explanation for correct option:

1. Ribosomes that occur on the nuclear membrane and E.R. are involved in protein synthesis.
2. Ribosomes are small structures that are present in both prokaryotes and eukaryotes.
3. They are genernally found attached to the nuclear membrane and the E.R. ribosomes are made up of ribosomal proteins and rRNA.
4. They contain two subunits, one smaller and one larger.
5. In ribosomes, the synthesis of protein takes place by the process of translation.

Explanation for incorrect options:

Option B

1. Ribosomes of only cytosol are not involved in protein synthesis.
2. Cytosol contains an organised framework that constitute the cytoskeleton, which gives shape to the cell and enables organelles to move in the cell.

Option C

1. Ribosomes of only nucleolus and cytosol.
2. The nucleolus is a structure present in the nucleus of eukaryotic cells it participates in assembling the ribosomes.
3. The nucleolus is composed of RNA and proteins.
4. cytosol is responsible for giving shape to the cell and maintaining cytoskeleton of the cell.

Option D

1. Ribosomes of only mitochondria and cytosol are not involved in protein synthesis.
2. The mitochondrial ribosome is also known as mitoribosome, is a protein complex active and mitochondria and functions as ribo protein.
3. cytosol is responsible for shape of cell and movement of organelles in the cell.

Final answer: Ribosomes that occur on the nuclear membrane and E.R. are involved in protein synthesis.