Which observed phenotypic pattern in a pedigree would make it more likely that an inherited trait is recessive rather than dominant?
A) Every affected individual has an affected parent.
B) About half of the offspring of an affected parent are also affected.
C) Some affected individuals have unaffected parents.
D) The family size is small.
E) The family size is large.

Question

Quizplus · Accepted Answer

If some affected individuals have unaffected parents, it suggests that the trait is recessive and that the unaffected parents are carriers of the allele. In a dominant trait, every affected individual would have at least one affected parent, and in a 50/50 inheritance pattern (option B), it could be either dominant or recessive. Family size is not indicative of the inheritance pattern.

Which Observed Phenotypic Pattern in a Pedigree Would Make It