If one of the strands of DNA has the following sequence of bases in the `5'-3'` direction :
`5'-G-A-A-T-A-C-C-G-G-T-A-3'`
(i) What is the sequence of bases in the complementary strand ?
(ii) Which base is closest to the 5'-end in the complementary strand ?

Explanation

According to base -pairing principle. G faces, C,T faces A and vice -versa in the complimentary strand of DNA. Thus , the sequence of bases in the complementary strand is : `3'-C-T-T-A-T-G-G-C-C-A-T-5'`.
(ii) Since the complimentary strands run in the opposite direction , therefore , the closest base to the 5'-end is T.