We say that DNA is complementary. This means that one side complements the other. Since we know the base-pairing rules..... if the bases on one side of the DNA were ACCGTA, what would be on the other side?
a)ACCGTA
b)TGGCAT
c)TCCGAT
d)AGGCAT
This is because in DNA, purines (A and G), pair with pyrimidines (C and T), and more specifically, adenine pairs with thymine and cytosine pairs with guanine. Per this base pairing, B should be the right answer.