Which of the following pairs of base sequences could form a short stretch of a normal double helix of DNA?
A) 5'-purine-pyrimidine-purine-pyrimidine-3' with 3'-purine-pyrimidine-purine-pyrimidine-5'
B) 5'-AGCT-3' with 5'-TCGA-3'
C) 5'-GCGC-3' with 5'-TATA-3'
D) 5'-ATGC-3' with 5'-GCAT-3'
E) All of these pairs are correct.

Question

Quizplus · Accepted Answer

DNA base pairing is specific, and adenine (A) only binds with thymine (T), while guanine (G) only binds with cytosine (C). Therefore, the only option that has complementary base pairs is D, where AT base pairs match with GC base pairs. A and B have the incorrect base pairing, and C has non-complementary base pairs.

Which of the Following Pairs of Base Sequences Could Form