Question

If a strand of DNA has the nitrogen base sequence 5'-ATTTGC-3', what will be the sequence of the matching strand?

Answer 1

3'-TAAACG-5'

Explanation:

According to Watson and crick base pairing and Chargaff's rule
adenosine pairs with thymine with 2 hydrogen bond
guanine pairs with cytosine with 3 hydrogen bond

the commentary strand is always in reverse direction (5 prime end and 3 prime end)