Target Exam

CUET

Subject

Biology

Chapter

Molecular Basis of Inheritance

Question:

The RNA polymerase I in the nucleus transcribes :

Options:

5s rRNA

tRNA

28s rRNA

snRNA

Correct Answer:

28s rRNA

Explanation:

The correct answer is Option (3) → 28s rRNA

In eukaryotes, there are  at least three RNA polymerases in the nucleus (in addition to the RNA polymerase found in the organelles). There is a clear cut division of labour.

(i) The RNA polymerase I transcribes rRNAs (28S, 18S, and 5.8S).

(ii) RNA polymerase III is responsible for transcription of tRNA, 5srRNA, and snRNAs (small nuclear RNAs).

(iii) The RNA polymerase II transcribes precursor of mRNA, the heterogeneous nuclear RNA (hnRNA).