Answer :
Answer:
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.