Question

Which mutation is most likely to have a severe impact on the phenotype of an organism if it occurs within the first several bases of a gene coding region?

A) a frameshift mutation of three nucleotides

B) a missense mutation affecting one nucleotide

C) a missense mutation affecting three nucleotides

D) a silent mutation affecting one nucleotide

E) a frameshift mutation of one nucleotide

Answer 1

Ans- E is correct. A frameshift mutation of one nucleotide likely to have a severe impact on the phenotype of an organism. Because frameshift mutation of one nucleotide cause change in more than one amino acids in a protein sequence. Frameshift mutation is a mutation in which addition or deletion of base pairs in a DNA resulting in the translation of the genetic code in an unnatural reading frame.

A frameshift mutation of three nucleotides only change one amino acid in a protein sequence.

Missense mutation and silent mutation is a point mutation that only affects one amino acid in a protein sequence.