Question

Example 1 below is a strand of DNA and mRNA used to make a protein. Example 2 below is the same DNA but a mutation has occurred. Use the mRNA strand and the codon chart below to determine the outcome in Example 2 compared to Example 1.



Codon Chart:



(1 point)
Responses

Although a mutation has occurred, the codon in Example 2 (CAC) still makes the same amino acid (His) as the codon in Example 1 (CAU). No change will occur.

The mutation also causes a change in the mRNA, so it will always make a new protein.

A mutation in DNA will not cause a change in mRNA.

Answer 1

Select the first response.

Explanation: CAU and CAC both code for histidine (His), so the DNA change produces a different mRNA codon but a synonymous (silent) mutation — the same amino acid and no change in the protein. The other two statements are incorrect: DNA mutations can change mRNA, and not every mutation alters the protein.