# DBT JRF 2022 — Question 1

Exam: DBT JRF 2022 · Section: A · Topic: Molecular Biology › RNA Polymerases & Transcription · Difficulty: Medium

## Question

In the Table given below, the column (A) lists three eukaryotic RNA Polymerases and column (B) lists group of genes they transcribe. Identify the correct match from the options below:
| A (RNA Polymerase) | B (Gene Group) |
| --- | --- |
| (i) RNA polymerase I | a. mRNA, miRNA, snRNA genes |
| (ii) RNA polymerase II | b. tRNA and 5S rRNA genes |
| (iii) RNA polymerase III | c. rRNA genes |

## Options

- **A.** i & c; ii & b; iii & a
- **B.** i & b; ii & c; iii & a
- **C.** i & b; ii & a; iii & c
- **D.** i & c; ii & a; iii & b

## Answer

Option D

## Explanation

Eukaryotes have three distinct nuclear RNA Polymerases, each dedicated to a specific class of genes: • RNA Pol I (in the nucleolus) transcribes the large ribosomal RNA precursor (45S pre-rRNA), which is processed into 18S, 5.8S, and 28S rRNAs. • RNA Pol II (in the nucleoplasm) transcribes all protein-coding genes into mRNAs, as well as most small non-coding RNAs including microRNAs (miRNA) and small nuclear RNAs (snRNA) involved in splicing. • RNA Pol III transcribes the small structural RNA genes: all tRNA genes and the 5S rRNA gene. This division of labour is conserved across all eukaryotes. Correct matching: i→RNA Pol I (rRNA), ii→RNA Pol II (mRNA/miRNA/snRNA), iii→RNA Pol III (tRNA/5S rRNA). Answer: (i & c; ii & b; iii & a) → Option 4.

Source: https://mypyqbuddy.com/questions/in-the-table-given-below-the-column-a-6a104cd5920734408bc0c6de