Science Assessment

Observation: Two grey mice had a baby mouse pup that was black.

Question: How did grey parents produce a black mouse pup?

Claim: A new allele of the MC1R gene was produced by mutation in one of the parent’s sex cells, and then passed on to the mouse pup.

Evidence: DNA sequencing revealed that the mouse pup has an allele of the MC1R gene that results in the production of more black pigment in the fur. Neither parent has a copy of this black MC1R allele in its body cells.

Which of the following statements provides the best reasoning to justify why the evidence supports the claim?

1. Mutation is a natural process that produces genetic variation.
2. DNA is passed from parents to offspring so that each individual has half their genetic information from their father and half their genetic information from their mother.
3. The black MC1R allele is dominant to the other MC1R allele.
4. Since offspring inherit DNA from their parents, if neither parent carried the black MC1R allele in its body cells, the allele must have been produced by mutation in a parent’s sex cell.