Nucleic acids are the biopolymers in which the repeating structural monomeric units is a nucleotide. The nucleotides structural monomeric unit is a nucleotide. The nucleotides consist of three components, a pentose sugar `(D-(0)-" ribose or 2 - deoxy "-D-(-)-"ribose, heterocyclic base")`, (purines i.e., adenine and guanine and pyridines i.e., thymine, cytosine and uracil) and phosphoric acid. Sugar - base constitutes nucleosides. the two types of nucleic acids are DNA and RNA. Nucleic acids play significant role in replication and protein synthesis.
If one of the strands of DNA has the following sequence of bases in the 5' - 3' direction.
`5'-A-G-T-C-A-A-G-3'`
Which base is closest to the 5' - end in the complementary strand?

Explanation

The complementary strand is :
`3.-T-C-A-G-T-T-C-5.`
Since the complementary strands run in the opposite direction, therefore, the closest base to the `5.-` end is C.