Q115 · Practice questionComplex familiar1 mark
QUESTION 115
Allele a produces a recessive phenotype only in aa individuals. Every aa individual fails to reproduce in one generation, but AA and Aa individuals reproduce. Why can a still be passed to offspring?
(A)
Selection converts the remaining a copies into A.
(B)
Aa individuals produce only A-bearing gametes.
(C)
Aa individuals can transmit a even though they lack the recessive phenotype.
(D)
An allele is inherited only when every carrier expresses its phenotype.
WORKED SOLUTION
1 markAnswer C
Answer
C
Working
Selection acts on the stated phenotype. Reproducing Aa individuals still carry a and can transmit it in their gametes, so loss of reproducing aa individuals does not immediately remove every a copy.
Marking criteria
- Select C. [1 mark]
Practice question aligned to the current QCAA syllabus; review the worked solution and marking criteria.
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