Question

Subunits of a mitochondrial ribosome in animal cells are

• A. 25S and 40S
• B. 28S and 39S
• C. 30S and 40S
• D. 40S and 20S

Answer 1

The correct option is B

28S and 39S

The correct option is (B)

The explanation for the correct option

1. Ribosomes are composed of several components.
2. In eukaryotes, mitochondrial ribosomes have the same size as those in prokaryotes.
3. They are 70S, a type of subunit composed of smaller subunits.
4. They're smaller than cytosolic ribosomes.
5. In mitochondria, two 28S and 39S ribosome units unite to generate a 55S ribosome.
6. Inside the electron transport chain, mitoribosomes are primarily responsible for protein production.
7. Mitoribosome dysfunction can lead to metabolic disorders.

The explanation for the Incorrect option:

Option A, C and D:
In animal cells, the mitochondrial ribosome subunits are 28S and 39S, not 25S and 40S.

Final answer: Subunits of a mitochondrial ribosome in animal cells are the 40S and 20S.