What are the complementary base-pairing rules for biology?
In DNA, Adenine bonds with Thymine, Cytosine bonds with Guanine. In RNA, Thymine is changed with Uracil (bases capitalized for easy emphasis/reference, not grammar.)
In DNA:
Adenine and Guanine: Purines
Cytosine and Thymine: Pyrimidines
Adenine bonds with Thymine and Guanine bonds with Cytosine.
A&T have 2 hydrogen bonds and G&C have 3 hydrogen bonds.