5 A single strand of DNA contains the following sequence 5 G

5. A single strand of DNA contains the following sequence: 5\' GATTCGTCAACTG 3\'; the complementary single strand is: a) 3\' CUAAGCAGUUGAC 5\' b) 3\' CTAAGCAGTTGAC 5\' c) 5\' CTAAGCAGTTGAC 3\' d) 5\' GUTTCGTCUUCGT 3\' e) 3\' CATTCGTCAACTG 5\'

Solution

5. A single strand of DNA contains the following sequence: 5\' GATTCGTCAACTG 3\' the complementary single strand is:

b) 3\' CTAAGCAGTTGAC 5\'

Reason:

1. Complemantary Base pairing:

A bonds with T (double bond)

G bonds with C (Triple bond)

2. Antiparallel strand:

both DNA strands are antiparallel i.e if one strand is 5-->3 then the other one is 3\'--> 5\'