Question

Given below are two statements:
Statement I: Alternative splicing generates uniform mRNA from identical pre-mRNA molecules
Statement II: Changes in splicing patterns may have many different effects on translated proteins
In the light of the above statements, choose the most appropriate answer from the options given below

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

Hint:

Alternative Splicing: Generates MULTIPLE DIVERSE mRNA isoforms from ONE pre-mRNA (NOT uniform mRNA), creating protein diversity from single genes.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
Post-transcriptional eukaryotic gene regulation: alternative pre-mRNA splicing generates diverse mRNA isoforms and distinct protein variants from a single gene locus.

Step 2: Detailed Explanation:
1. Statement I: Alternative Splicing is a regulated post-transcriptional process where different combinations of exons from a single primary pre-mRNA transcript are spliced together or skipped. It generates multiple diverse, non-uniform mRNA isoforms, NOT uniform mRNA. Hence, Statement I is incorrect.
2. Statement II: Differential exon inclusion/exclusion alters the open reading frame, generating protein isoforms with varied catalytic activities, receptor affinities, subcellular localizations, or regulatory domains (e.g., membrane-bound vs secreted antibodies). Hence, Statement II is correct.

Step 3: Final Answer:
Therefore, Statement I is incorrect but Statement II is correct, matching option (D).