What is the sequence of the complementary strand of DNA given the template DNA sequence below? (Note: Spaces between nucleotides have no purpose but to make the sequences easier to read.)
A) 5'-GCC TCG GAA CGT CTT CGA-3'
B) 3'-GCC CTG GAA CGT CTT CGA-5'
C) 3'-GCC UCG GAA CGT CUU CGA-5'
D) 5'-CGA GGC GTC AAC TCG CTT-3'
E) 3'-CGG AGC CTT GCT GAA GCT-5'

Question

What is the sequence of the complementary strand of DNA given the template DNA sequence below? (Note: Spaces between nucleotides have no purpose but to make the sequences easier to read.) 
A) 5'-GCC TCG GAA CGT CTT CGA-3' 
B) 3'-GCC CTG GAA CGT CTT CGA-5' 
C) 3'-GCC UCG GAA CGT CUU CGA-5' 
D) 5'-CGA GGC GTC AAC TCG CTT-3' 
E) 3'-CGG AGC CTT GCT GAA GCT-5'

Quizplus · Accepted Answer

To determine the complementary strand of DNA, we need to use the base-pairing rules: A pairs with T and C pairs with G. In the given template DNA sequence, we have:
5'-GCC CTG GAA CGT CTT CGA-3'

The complementary strand will have the opposite sequence but the same directionality (5' to 3'):
3'-CGG GAC CTT GCA GAA GCT-5'

However, the question is asking for the complementary strand in the reverse direction (3' to 5'), which can be denoted by adding a prime ('') symbol. So the final answer is: 
3'S1'-CGG GAC CTT GCA GAA GCT-5'

Option A has the correct sequence but in the wrong directionality (5' to 3' instead of 3' to 5'). Option C has incorrect base-pairings (using U instead of T). Option D has the correct base-pairings but in the wrong order (not complementary). Option E also has incorrect base-pairings.

What Is the Sequence of the Complementary Strand of DNA