Question

Consider the following and choose the correct answer Assertion [A]: B-DNA is the most stable and predominant form of DNA under physiological conditions. Reason [R]: B-DNA possesses major and minor grooves. The correct answer is

• A. Both [A] and [R] are true and [R] is the correct explanation of [A]
• B. Both [A] and [R] are true and [R] is not the correct explanation of [A]
• C. [A] is true, but [R] is false
• D. [A] is false, but [R] is true

Hint:

Characteristics of B-DNA: \[ \boxed{ \begin{aligned} &\text{Most common DNA form} &\text{10 base pairs per turn} &\text{Major and minor grooves present} \end{aligned} } \]

Answer 1

The Correct Option is B

Step 1: Examine the assertion. B-DNA is the predominant and most stable form of DNA under normal physiological conditions. Hence, \[ \boxed{\text{Assertion [A] is true}.} \]

Step 2: Examine the reason. B-DNA possesses one major groove and one minor groove. Thus, \[ \boxed{\text{Reason [R] is true}.} \]

Step 3: Establish the relationship. Although B-DNA has major and minor grooves, this fact does not explain why it is the most stable DNA form under physiological conditions. Therefore, \[ \boxed{ \text{Both [A] and [R] are true, but [R] is not the correct explanation of [A].} } \] Hence, \[ \boxed{(B)} \] is the correct answer.