Question

In the gene TATTCATTGTTA—TGATTT—ATTCG, CATTGTTA encodes for pepsin, a digestive enzyme. The rest of the sequence doesn’t code for any protein. Which sequence contains a mutation that will affect the formation of pepsin?
TATTCATTCATTA—TGATTT—ATTCG



TATTCATTGTTA—TGACTTT—ATTCG



TATTCATTGTTA—TGATTT—ATTGGCG



TATTCATTGTTA—TGAT—ATTCG



TGCATTCATTGTTA—TGATTT—ATTCG

Answer 1

Answer:

TATTCATTCATTA—TGATTT—ATTCG

Explanation:

A mutation is a permanent change in the nucleotide sequence of DNA. A mutation occurs during replication or recombination. It may be due to base substitutions, deletions and insertions. As per the question, DNA segment forms encodes for the enzyme pepsin is CATTGTTA.

Option TATTCATTCATTA—TGATTT—ATTCG is the correct answer. In the DNA segment which encodes pepsin, a purine base (G) guanine is replaced by another purine (A) adenine. This type of mutation is called a transition type point mutation.

Due to base substitution, the mutated segment CATTCATTA will nor encode pepsin.