Q116 · Practice questionComplex familiar1 mark
QUESTION 116
A source population contains 50 AA and 50 aa individuals. Two Aa offspring from this population found a new island population. What is true of A frequency at this locus in the source and founder populations?
(A)
The founders must have A frequency 1.00.
(B)
Both have A frequency 0.50 despite different genotype proportions.
(C)
The source has A frequency 0.25.
(D)
The founders must lack allele a.
WORKED SOLUTION
1 markAnswer B
Answer
B
Working
The source has 100 A alleles among 200, and the founders have 2 A among 4. Both frequencies are 0.50 despite very different genotype frequencies. Small founder groups can lose diversity at other loci; that is not demonstrated for the tracked allele here.
Marking criteria
- Select B. [1 mark]
Practice question aligned to the current QCAA syllabus; review the worked solution and marking criteria.
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