Final answer:
The base pairs in DNA are A and T, and G and C. Adenine always pairs with thymine, and guanine always pairs with cytosine.
Step-by-step explanation:
The base pairs in DNA are A and T (adenine and thymine) and G and C (guanine and cytosine). These base pairs are called complementary base pairs because they always pair together. Adenine always pairs with thymine, and guanine always pairs with cytosine.