If a pedigree shows affected individuals with unaffected parents, what does this imply about dominance and allele frequency?

• A. The trait is recessive; affected individuals are often homozygous recessive, and carriers exist among unaffected parents.
• B. The trait is dominant; affected individuals have affected parents.
• C. The trait is polygenic; carriers absent.
• D. The trait is X-linked; mostly males.

Answer: (A)