Question

question 6 of 10
which mutation would likely have the largest effect on an enzyme?
a. a frameshift mutation near the end of a gene
b. an insertion of three nucleotides near the end of the gene
c. a substitution that produces a stop codon at the beginning of a gene
d. a deletion of three nucleotides near the end of the gene

Explanation:

A stop codon at the beginning of a gene would halt protein synthesis early. Enzymes are proteins, so this mutation would likely prevent the enzyme from being formed at all. A frameshift near the end (A) affects some codons but not as severely as a start - stop. Insertion/deletion of three nucleotides (B, D) is one codon, so less disruptive than a premature stop.

Answer:

C. A substitution that produces a stop codon at the beginning of a gene