RNA Instability and Viral Evolution — NEET Biology
✅ Asked in NEET 2023Given below are two statements: (NEET 2023) Statement I: RNA mutates at a faster rate. Statement II: Viruses having RNA genome and shorter life span mutate and evolve faster. Choose the correct answer:
Given below are two statements: (NEET 2023) Statement I: RNA mutates at a faster rate. Statement II: Viruses having RNA genome and shorter life span mutate and evolve faster. Choose the correct answer:
Answer & NCERT explanation
Correct answer: B — Both Statement I and Statement II are true.
Both statements are correct. RNA lacks 3'-exonuclease activity and has 2'-OH group making it less stable, hence mutates faster than DNA. RNA viruses have shorter generation time and higher mutation rates, leading to faster evolution. This explains why RNA viruses like influenza and HIV evolve rapidly, requiring frequent vaccine updates.
Read more NCERT concept on the PYQ
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.
NTA tests whether students understand that RNA's structural instability causes higher mutation rates compared to DNA, leading to rapid evolution in RNA viruses. Many students incorrectly assume DNA and RNA mutate at equal rates or confuse viral evolution with bacterial adaptation. The key trap is thinking mutation rate depends on genome size or replication speed rather than chemical stability. Remember: RNA lacks the 2'-OH group protection of DNA, making it chemically unstable and prone to degradation and errors. RNA viruses like influenza mutate faster because each replication introduces more errors, enabling them to evolve and escape immune responses quickly. This concept directly tests molecular basis of inheritance and viral genetics.
What does NCERT say about Both DNA and RNA?
Has this concept appeared in NEET?
Which chapter is this from?
Through deep analysis of NEET and NTA, 176 of the 180 ReNEET 2026 (June 21) questions were already in the MedicNEET question bank before the exam.
176/180MedicNEET's Biology question bank is built from the same NCERT lines NTA picks repeatedly. Not random MCQs — questions crafted exactly like NTA crafts them.