A stretch of one strand of a DNA fragment is 5′-GTCATCGTACT-3′.What is the complementary strand?
A) 5′-GTCATCGTACT-3′
B) 3′-GTCATCGTACT-5′
C) 5′-CAGTAGCATGA-3′
D) 3′-CAGTAGCATGA-5′
E) 5′-GTCAGACTACA-3′

Question

Quizplus · Accepted Answer

The complementary strand of DNA follows base pairing rules where adenine pairs with thymine and cytosine pairs with guanine. In order to find the complementary strand, we need to replace each base with its complementary base. Therefore, the complementary strand will be 3′-CAGTAGCATGA-5′.

A Stretch of One Strand of a DNA Fragment Is