Which of the following statements is correct?
- Adenine does not pair with thymine
- Adenine pairs with thymine through one H-bond
- Adenine pairs with thymine through two H-bonds
- Adenine pairs with thymine through three H-bonds
Answer
(3) Adenine pairs with thymine through two H-bonds
Solution
As per NCERT (Watson–Crick model), the bases of the two strands pair through hydrogen bonds: adenine forms two hydrogen bonds with thymine (A=T), and guanine forms three hydrogen bonds with cytosine (G C).
Answer: (3)