Question

Normally DNA molecule has A-T, G-C pairing. However, these bases can exist in alternative valency status, owing to rearrangements called as

• A. Point mutation
• B. Analogue substitution
• C. Frame-shift mutation
• D. Tautomerisational mutation

Answer 1

Answer: (D)

Tautomerisational mutation

Watson and Crick pointed that the bases in DNA are not static. Movement of Hydrogen atoms from one base to another base results in tautomeric shifts that result in tautomerization mutation. These mutations are unstable and remain for a short period. If the changed bases are replicated, mutations may occur resulting in imino or enol bases forming Adenine-cytosine and Guanine-Thymine base pairs.

So, the correct answer is 'Tautomerisational mutation'.