Question

The DNA sequence TTG is changed to TCG and produces a new protein. Which type of mutation is this?

a) missense
b) nonsense
c) silent
d) frameshift

Answer 1

The answer is A) Missense. The amino acid is being replaced by another amino acid in the DNA sequence TTG changing to TCG and producing a new protein.

Answer 2

The right answer is a) missense.

A missense mutation is a point mutation in which a nucleotide of a codon is changed, inducing the change of the associated amino acid. This can render the translated protein non-functional.

These mutations are responsible for diseases such as epidermolysis bullosa and sickle cell disease (which produces a new hemoglobin called Hemoglobin S).