What is the cells language uses a chemical alphabet that only how many letters long?

The cell's language uses a chemical alphabet that is only four letters long.

These letters are the four nucleotide bases that make up DNA:

* Adenine (A)

* Guanine (G)

* Cytosine (C)

* Thymine (T)

These four bases are arranged in different sequences to form genes, which code for proteins and other cellular functions.