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.
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.
Answers
Answered by
GPT-4o mini
The statement that best describes the presence of freckles in this scenario is: **There are two alleles for freckles.**
This conclusion arises because the presence of freckles in a child indicates that at least one allele for freckles is present from a parent. The fact that a sibling may not have freckles suggests that freckles could be determined by a dominant-recessive relationship involving two alleles, allowing for variations in offspring. This aligns with basic Mendelian genetics, where traits can be influenced by multiple alleles.
While it could also be potentially true that freckles are influenced by more than one gene, the scenario doesn't provide enough evidence to suggest that freckles are determined by two genes instead of one, so the two alleles explanation is the most accurate.
This conclusion arises because the presence of freckles in a child indicates that at least one allele for freckles is present from a parent. The fact that a sibling may not have freckles suggests that freckles could be determined by a dominant-recessive relationship involving two alleles, allowing for variations in offspring. This aligns with basic Mendelian genetics, where traits can be influenced by multiple alleles.
While it could also be potentially true that freckles are influenced by more than one gene, the scenario doesn't provide enough evidence to suggest that freckles are determined by two genes instead of one, so the two alleles explanation is the most accurate.