48. 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                                                                                   B
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

Introduction:

Eukaryotic cells rely on three distinct RNA polymerases to transcribe their genetic material. Each RNA polymerase plays a crucial role in transcribing specific types of RNA molecules that are vital for cellular functions. Understanding which RNA polymerase transcribes which type of gene is fundamental to grasping the complexities of gene expression. In this article, we will review the roles of RNA polymerases I, II, and III and match them with the genes they transcribe.

The Three Eukaryotic RNA Polymerases:

1. RNA Polymerase I: RNA polymerase I is responsible for transcribing the majority of rRNA genes, specifically the genes encoding ribosomal RNA (rRNA), which are essential components of ribosomes. These rRNA molecules are crucial for protein synthesis in the cell.

2. RNA Polymerase II: RNA polymerase II transcribes protein-coding genes into mRNA (messenger RNA), as well as miRNA (microRNA) and snRNA (small nuclear RNA). These types of RNA play significant roles in regulating gene expression and processing mRNA.

3. RNA Polymerase III: RNA polymerase III is responsible for transcribing genes encoding smaller RNA molecules, including tRNA (transfer RNA) and 5S rRNA, both of which are essential for protein synthesis.

The Table of RNA Polymerases and Their Transcription Targets:

Column (A): RNA Polymerases

1. RNA polymerase I: Transcribes rRNA genes

2. RNA polymerase II: Transcribes mRNA, miRNA, and snRNA genes

3. RNA polymerase III: Transcribes tRNA and 5S rRNA genes

Column (B): Genes Transcribed

a. mRNA, miRNA, snRNA genes b. tRNA and 5S rRNA genes c. rRNA genes

Correct Matching:

Let’s match the RNA polymerases with the correct group of genes they transcribe:

• RNA polymerase I transcribes rRNA genes (option c).

• RNA polymerase II transcribes mRNA, miRNA, and snRNA genes (option a).

• RNA polymerase III transcribes tRNA and 5S rRNA genes (option b).

So the correct matching is: i & c; ii & a; iii & b

Conclusion:

Understanding the distinct roles of the three eukaryotic RNA polymerases helps us appreciate how cells regulate gene expression to ensure proper functioning. RNA polymerase I, II, and III each have specialized functions in transcribing different classes of RNA, which are critical for the cell’s life processes.

Answer:

A. i & c; ii & a; iii & b