Given the choice of 4 bases and the number of bases needed to make up a codon, how many possible codons are there? 16 23 64 128

64

Explanation:

A codon is a group of three nucleotide sequence in a mRNA that specifies a particular amino acid acid. There are only four nucleotides composed of the four nitrogenous bases viz: Adenine, Guanine, Cytosine and Thymine/Uracil.

A codon is composed of only three of these nucleotide bases at a time. Hence, considering the number of nucleotide bases that can make up one codon and the 4 nucleotide bases, there can only be 4^3 = 64 combinations of the four nucleotides. This means that there are 64 possible codons.