Match List-I with List-II
| List-I | List-II |
|---|---|
| Enzymes | Products/function |
| (A) RNA polymerase I | (I) tRNA, 5srRNA, and snRNAs |
| (B) RNA polymerase III | (II) rRNAs (28S, 18S, and 5.8S) |
| (C) RNases | (III) Heterogeneous nuclear RNA |
| (D) RNA polymerase II | (IV) RNA digestion |
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → (A) - (II), (B) - (I), (C) - (IV), (D) - (III)
In eukaryotes there are at least three RNA polymerases in the nucleus, and each makes a different kind of RNA.
(A) RNA polymerase I — this matches (II) rRNAs (28S, 18S, and 5.8S). It makes the large ribosomal RNAs, which form the structure of the ribosome.
(B) RNA polymerase III — this matches (I) tRNA, 5srRNA, and snRNAs. It makes the small RNAs: transfer RNA, the 5S rRNA and the small nuclear RNAs.
(C) RNases — this matches (IV) RNA digestion. RNases are not polymerases. They are enzymes that break down (digest) RNA. During DNA isolation, for example, RNA is removed by treatment with ribonuclease.
(D) RNA polymerase II — this matches (III) Heterogeneous nuclear RNA. It makes the precursor of mRNA, called hnRNA. The hnRNA is later spliced, capped and tailed to become mRNA.
NCERT Extract:
Transcription Unit and the Gene – “… (i) 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. The RNA polymerase I transcribes rRNAs (28S, 18S, and 5.8S), whereas the RNA polymerase III is responsible for transcription of tRNA, 5srRNA, and snRNAs (small nuclear RNAs). The RNA polymerase II transcribes precursor of mRNA, the heterogeneous nuclear RNA (hnRNA).”