Final answer:
The nitrogenous bases of DNA have complementary base pairing. Adenine (A) pairs with Thymine (T), and Cytosine (C) pairs with Guanine (G). In RNA, Uracil (U) replaces Thymine as the complementary base to Adenine. So, the correct matches are A and B.
Step-by-step explanation:
In DNA, adenine (A) pairs with thymine (T), and cytosine (C) pairs with guanine (G). The correct matches are:
A. Adenine - Thymine: Adenine always forms a complementary base pair with thymine in DNA. This pairing is stabilized by two hydrogen bonds.
B. Cytosine - Guanine: Cytosine always pairs with guanine in DNA, forming three hydrogen bonds between them.
The incorrect matches are:
C. Adenine - Uracil: This pairing is found in RNA, not DNA. In RNA, adenine pairs with uracil.
D. Guanine - Cytosine: This is a correct match. Guanine always pairs with cytosine in DNA, forming three hydrogen bonds.
So, the correct matches are A and B.