Question

Which of the following base-pairing rules is correct ?

Answer 1

There are various base-pairing rules for DNA and RNA.

Explanation:

1. DNA to DNA

• Possible Bases: Adenine, Thymine, Cytosine, Guanine
• G↔C, A↔T
• A and G are purines (double‐ring), C and T are pyrimidines (single‐ring)

2. DNA to mRNA

• Possible Bases: Adenine, Thymine, Cytosine, Guanine, Uracil (RNA only)
• G↔C, A→U, T→A
• A and G are purines (double‐ring), C, T, and U are pyrimidines (single‐ring)

3. mRNA to tRNA

• Possible Bases: Adenine, Cytosine, Guanine, Uracil
• G↔C, A↔U
• A and G are purines (double‐ring), C, T, and U are pyrimidines (single‐ring)