Question

Given below are two statements:
Statement I: In eukaryotes there are three RNA polymerases in the nucleus in addition to the RNA polymerase found in the organelles.
Statement II: All the three RNA polymerases in eukaryotic nucleus have different roles.
In the light of the above statements, choose the correct answer from the options given below:

• A. Statement I is correct but Statement II is incorrect
• B. Statement I is incorrect but Statement II is correct
• C. Both Statement I and Statement II are correct
• D. Both Statement I and Statement II are incorrect

Answer 1

The Correct Option is C

The question involves understanding the roles and existence of RNA polymerases in eukaryotic cells. Let's analyze each statement:

1. Statement I: In eukaryotes there are three RNA polymerases in the nucleus in addition to the RNA polymerase found in the organelles.

This statement is correct. In the eukaryotic cells, generally, there are three main types of RNA polymerases present in the nucleus:

• RNA Polymerase I: Primarily responsible for synthesizing rRNA (ribosomal RNA), except for the 5S rRNA.
• RNA Polymerase II: Synthesizes mRNA (messenger RNA) and some snRNA (small nuclear RNA).
• RNA Polymerase III: Responsible for synthesizing tRNA (transfer RNA), 5S rRNA, and other small RNAs.

Additionally, organelles such as mitochondria and chloroplasts have their own polymerases, distinct from the three nuclear types.

2. Statement II: All the three RNA polymerases in eukaryotic nucleus have different roles.

This statement is also correct. As described, each of the three types of nuclear RNA polymerases are responsible for transcribing different types of RNA:

• RNA Polymerase I: Produces most of the rRNAs, which are essential components of ribosomes and thus critical for protein synthesis.
• RNA Polymerase II: Transcribes mRNA, which is essential for conveying genetic information from DNA to the ribosome, where proteins are synthesized.
• RNA Polymerase III: Synthesizes tRNA and some rRNA components, playing a crucial role in translation and protein assembly.

Thus, both statements correctly describe the presence and unique functions of the RNA polymerases in eukaryotic cells.

Conclusion: Both Statement I and Statement II are correct, as they accurately describe the presence of RNA polymerases in eukaryotic nuclei and their distinct roles.

Correct Answer: Both Statement I and Statement II are correct.