Chargoff's rules states that which nucleotide pairings occurred?

• A. A and G, C and T
• B. T and U, C and G
• C. G and U, C and A
• D. A and T, C and G

Answer: (D)

Verified step by step guidance

1. Understand Chargaff's rules: These rules state that in a DNA molecule, the amount of adenine (A) is equal to thymine (T), and the amount of cytosine (C) is equal to guanine (G). This is due to the base pairing nature of DNA.
2. Recognize the base pairing: In DNA, adenine pairs with thymine through two hydrogen bonds, and cytosine pairs with guanine through three hydrogen bonds. This complementary base pairing is crucial for the structure and function of DNA.
3. Identify the correct nucleotide pairings: Based on Chargaff's rules, the correct pairings are A with T and C with G. This ensures the DNA strands are complementary and can form the double helix structure.
4. Eliminate incorrect options: Review the given options and eliminate those that do not match the base pairing rules. For example, A and G, C and T do not follow Chargaff's rules.
5. Confirm the correct answer: After eliminating incorrect options, confirm that the correct nucleotide pairings according to Chargaff's rules are A and T, C and G.