Apentix/AP Biology/Unit 5: Heredity/Question

AP Biologyeasymcq1 pt

For a single autosomal gene with complete dominance, what phenotypic ratio is expected from the cross Aa × aa?

A.1 dominant : 1 recessive offspring

B.3 dominant : 1 recessive offspring

C.all offspring with dominant phenotype

D.all offspring with recessive phenotype

Explanation

Core Concept

Under complete dominance, Aa × aa produces 50% Aa offspring with the dominant phenotype and 50% aa offspring with the recessive phenotype. The original word 'always' was too broad without stating the Mendelian assumptions.

Correct Answer

A1 dominant : 1 recessive offspring

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