A group of students is investigating gene mutations. They learn about a mutation that causes albino traits in house cats. The image shows the physical appearance and 4 codons of a DNA sequence of a cat with the albino mutation and a cat without the albino mutation.

Question

The house cat with an albino mutation has a white physical appearance, and the DNA sequence for it is CCT-CCT-CTG-CTG. The house cat without an albino mutation has a brown physical appearance, and the DNA sequence for it is CCC-TCC-TCT-GCT.

Multiple Choice Question
How did the mutation affect the albino cat?

A.
The mutation changed the structure of the genes, which changed the structure of the proteins. This change affected the location of the genes, which caused the cat to have albino traits.

B.
The mutation changed the structure of the genes, which changed the structure of the proteins. This change affected the function of the proteins, which caused the cat to have albino traits.

C.
The mutation changed the structure of the proteins, which changed the structure of the chromosomes. This change affected the location of the genes, which caused the cat to have albino traits.

D.
The mutation changed the structure of the proteins, which changed the structure of the chromosomes. This change affected the function of the proteins, which caused the cat to have albino traits.

Answer 1

The correct answer is:

B. The mutation changed the structure of the genes, which changed the structure of the proteins. This change affected the function of the proteins, which caused the cat to have albino traits.

This option correctly describes how a mutation in the DNA sequence can lead to a change in the structure and function of proteins, ultimately resulting in the phenotypic difference observed (in this case, the albino trait). The changes in the specific codons (CCT vs. CCC, CTG vs. TCT, etc.) likely led to a functional change in proteins involved in pigmentation, resulting in the albino appearance.