In a double-stranded DNA, adenine pairs with thymine by how many hydrogen bonds? MCQ with Answer and Explanation

In a double-stranded DNA, adenine pairs with thymine by how many hydrogen bonds?
A. Three
B. One
C. Two
D. Four
Answer: Option C
Solution (By JKSSB Mock Tests)
Adenine (A) pairs with thymine (T) via two hydrogen bonds. Guanine (G) pairs with cytosine (C) via three hydrogen bonds. This base pairing (complementarity) is key to the double helix structure and ensures accurate replication and transcription. The higher number of bonds between G-C contributes to DNA stability; GC-rich regions are harder to denature.

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Correct Answer: Option B


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