TCTCG and AGAGC are the perfect pair.
Option A
<h3><u>Explanation:</u></h3>
DNA is the genetic molecule of a living cell. The DNA stores genetic information of the species inside itself by means of particular pattern or sequence of nitrogen bases called as gene. The gene is comprised of the particular sequence of nitrogenous bases which are four in number - adenine, guanine, thymine and cytosine.
The nitrogen bases are present in both the strands of DNA and they have complementary relationship between them. The adenine forms hydrogen bonds with thymine and guanine pairs with cytosine.
Here the sequence of one strand is given as TCTCG. So according to the complementary pairing process, the opposite strand must have the sequence of AGAGC to maintain the structure.
