Q48.Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R.
Assertion A:
Scientists believe that RNA is the primitive genetic material.
Reason R:
RNA has the ability to catalyze chemical reactions.
In the light of the above statements, choose the most appropriate answer from the options given below:
(1) Both A and R are correct and R is the correct explanation of A
(2) Both A and R are correct but R is not the correct explanation of A
(3) A is correct but R is not correct
(4) A is not correct but R is correct
Both Assertion A and Reason R are correct, and R correctly explains A, making option (1) the right choice. This NEET-style question tests the RNA World hypothesis from molecular evolution.
Option Analysis
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Option (1): Both correct, R explains A. Correct—scientists support RNA as primitive genetic material due to its catalytic ability (ribozymes), enabling self-replication in early life.
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Option (2): Both correct, R doesn’t explain. Incorrect—R (catalysis) directly supports why RNA could function without proteins/DNA.
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Option (3): A correct, R false. Incorrect—R true; RNA acts as enzymes (e.g., ribosome peptidyl transferase).
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Option (4): A false, R true. Incorrect—A true; RNA World widely accepted based on ribozyme discovery.
RNA is the primitive genetic material—this core idea from the RNA World hypothesis powers NEET assertion-reason questions like Q48. Unlock why Assertion A holds, Reason R explains it perfectly, and option (1) scores full marks.
RNA World Hypothesis Basics
In prebiotic Earth (~4 billion years ago), RNA served dual roles: storing genetic info (like DNA) and catalyzing reactions (like proteins). This “RNA World” preceded DNA-protein systems, as RNA enables self-replication without enzymes.
Why R Explains A
RNA’s catalytic power (ribozymes) allows it to replicate itself, mutate, and evolve—key for primitive life. Evidence: ribosomes (RNA enzymes), viroids (self-replicating RNA). Without catalysis, RNA couldn’t be “genetic material”.
NEET Exam Insights
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Recall: RNA uracil (vs DNA thymine), single-stranded flexibility, 2′-OH enables catalysis.
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Common trap: Confusing RNA stability (DNA better long-term) with primitive role.
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Link to syllabus: Molecular Basis of Inheritance.
Master RNA is the primitive genetic material for 100% accuracy in evolution questions. Practice more ARQs!
