Question

There are three nucleotides in each codon, and each of these nucleotides can have one of four different bas- es. How many possible unique codons are there?

Answer 1

Answer: 64

Explanation:

A codon is a nucleotide sequence made up of three nucleotides that codes for a specific amino acid. Proteins are synthesized in the ribosome in a process called translation. During translation, these nucleotide triplets are read in a successive and non overlapping manner. A nucleotide is made up of a pyrimidine or purine base, a ribose sugar and a phosphate group. The base distinguishes one nucleotide from another. The bases present in a messenger RNA (mRNA) are uracil (U), cytosine (C), adenine (A) and guanine (G). The number of possible codons can be calculated as follows: 4x4x4=64.

See the attached diagram for illustration.

Answer 2

64

Step-by-step explanation:

One codon has three nucleotides. There are four types of nucleotides present in mRNA. These nucleotides differ from each other with respect to the nitrogenous base present in them. These bases present in the mRNA are uracil, guanine, cytosine, and adenine. Therefore, each codon of a triplet code can be replaced with three other nucleotides to produce a different codon. This means that a triplet can have four different bases for each of its three nucleotides. In this way, there are total of 4^3= 64 unique codons.