Target Exam

CUET

Subject

Biology

Chapter

Molecular Basis of Inheritance

Question:

Why is DNA considered a more stable genetic material compared to RNA?

Options:

DNA lacks the 2'-OH group that makes RNA more reactive.

RNA does not have catalytic properties like DNA.

DNA mutates more frequently than RNA.

DNA can code for protein synthesis directly, unlike RNA.

Correct Answer:

DNA lacks the 2'-OH group that makes RNA more reactive.

Explanation:

The correct answer is Option (1) – DNA lacks the 2'-OH group that makes RNA more reactive.

2'-OH group present at every nucleotide in RNA is a reactive group and makes RNA labile and easily degradable. DNA lacks the 2'-OH group that makes RNA more reactive. RNA is also now known to be catalytic, hence reactive. Therefore, DNA chemically is less reactive and structurally more stable when compared to RNA. Therefore, among the two nucleic acids, the DNA is a better genetic material. In fact, the presence of thymine at the place of uracil also confers additional stability to DNA. Both DNA and RNA are able to mutate. In fact, RNA being unstable, mutate at a faster rate. Consequently, viruses having RNA genome and having shorter life span mutate and evolve faster.