Question

which best describes a codon?
a cell structure that gives the master instructions for an organism
a segment of dna that is the basis of heredity in organisms
the sequence of three bases that codes for a specific amino acid
the basic unit of structure and function of all living things

Explanation:

A codon is a triplet of nucleotides (three - base sequence) in mRNA that codes for a specific amino acid during protein synthesis. The first option describes a cell structure like the nucleus which contains DNA with master instructions. The second option describes a gene. The fourth option describes a cell.

Answer:

the sequence of three bases that codes for a specific amino acid