2025 Molecular Basis of InheritanceRNA World Medium Question 1 of 2 in RNA World

Given below are two statements:
Statement I: In the RNA world, RNA is considered the first genetic material evolved to carry out essential life processes. RNA acts as a genetic material and also as a catalyst for some important biochemical reactions in living systems. Being reactive, RNA is unstable.
Statement II: DNA evolved from RNA and is a more stable genetic material. Its double helical strands being complementary, resist changes by evolving repairing mechanism.
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

The answer is A.

Solution

Both statements correctly describe the RNA world and evolution of stable DNA.

RNA acted as both the initial genetic repository and biocatalyst. Due to 2'-OH groups, RNA is reactive and labile. DNA evolved via methylation (uracil to thymine) and deoxygenation into a double-stranded complementary helix with repair mechanisms, providing chemical and structural stability.

Concept RNA vs DNA Evolution

RNA World in past papers

2 questions from this chapter have appeared across 2 exam years.