noun. a base found in DNA and RNA and derived from pyrimidine; pairs with guanine.
- deoxyribonucleic acid
- ribonucleic acid
- desoxyribonucleic acid
Example sentences of the word cytosine
1. Noun, singular or mass
Adenine and thymine form one pair while cytosine and guanine form the other pair.
2. Verb, base form
This is then converted to orotic acid, which can then become either cytosine or thymine.