Question

some people have freckles, and some people do not have freckles. if a child has freckles, at least one parent has freckles. however, the child may have a sibling that does not have freckles. which statement best describes the presence of freckles?
○ freckles are not determined by dna.
○ there are two alleles for freckles.
○ there is no dominant allele for freckles.
○ freckles are determined by two genes instead of by one.

Explanation:

• Option 1: Freckles are genetic (determined by DNA), so this is wrong.
• Option 2: The scenario (child with freckles, sibling without, at least one parent with freckles) fits a trait with two alleles (e.g., dominant and recessive). If freckles are dominant, parents with at least one dominant allele can have a child with freckles, and a sibling without (if they inherit recessive alleles from both parents). This is consistent.
• Option 3: The fact that a child with freckles has at least one parent with freckles suggests a dominant allele (since dominant traits can be inherited from one parent), so this is wrong.
• Option 4: The description doesn't imply two genes; it's more consistent with a single - gene trait with two alleles. So this is wrong.

Answer:

B. There are two alleles for freckles.