It's Paired With Cytosine in a DNA Strand
This page is the CodyCross answer for the clue below from Café, Group 1339, Puzzle 3 (Croissants).
Question is: It's Paired With Cytosine in a DNA Strand
and the answer is: GUANINE
Word Meaning:
GUANINE — (chemistry) A substance first obtained from guano; it is a nucleic base and pairs with cytosine in DNA and RNA (by means of three hydrogen bonds).
Definitions from Wiktionary.