Dr. Stevens is examining the DNA sequences of a group of mice. He notices that in one of the mice, one nucleotide has been substituted with another in the part of the DNA sequence that codes for fur color. However, despite the substitution, the mouse still has the same fur color as the other mice that have the typical DNA sequence. What best explains why the nucleotide substitution in the mouse does not change its phenotype?

Silent mutation

Explanation:

Mutation simply means a change in the nucleotide base sequence of a given gene. Mutation can happen by insertion, deletion, duplication, repetition or substitution.

Mutation can result in substitution of the original amino acid by another amino acid in a protein. This is known as missense mutation. On the other hand, some mutation results in shortened or incomplete protein otherwise known as nonsense mutation.

Some mutation however, results in no change to the amino acid sequence of a protein or no change to the function of the protein. This is known as silent mutation.

The substitution of nucleotide observed by Dr. Steven did not result in any change to the function of the resulting protein and hence, the phenotype. Dr. Steven must have observed silent mutation.

hammurabi rulers

good lesson