Guanine (noun)

1. A purine base that is a constituent of DNA and RNA, and that is derived from guanine.
2. A nitrogenous compound that is a constituent of DNA and RNA, and is one of the four nucleotide bases.

Origin:

From guano + -ine.

Examples:

1. Guanine is one of the four nucleotide bases in DNA.
2. Guanine is a purine base found in DNA and RNA.
3. Guanine is a nitrogenous compound that plays a crucial role in the genetic code.
4. Guanine is a component of DNA and RNA and is one of the four bases that make up the genetic code.
5. Guanine pairs with cytosine in the DNA double helix.