Question

As a result of a mutation, the DNA sequence AGT - TGA - CAT changes to AAT - TGA - CAT.

Which best describes the mutation?

It is a substitution in which the DNA base, G, was replaced with a different DNA base, A.
It is a deletion in which the DNA base, G, was replaced with a different DNA base, A.
It is a substitution in which three DNA bases, AGT, were replaced with three different DNA bases, AAT.
It is a deletion in which three DNA bases, AGT, were replaced with three different DNA bases, AAT.

Answer 1

Answer:

What best describes the mutation in the DNA strand is a substitution in which the DNA base "G" was replaced with a different DNA base "A".

Explanation:

The substitution of a nucleotide - as in this case the change of guanine for adenine - implies a change in the original sequence of nucleotides and corresponds to a type of genetic mutation called punctual mutation.

This type of mutation may or may not have effects on the synthesis of specific protein that the DNA encodes.

The other options are not valid because:

• The substitution that occurs is of a single nucleotide, not three.
• Deletions occur with the loss of one or several nucleotides in the chain, and this case illustrates a substitution.

Answer 2

Answer:

The answer is A

Explanation:

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