Q24 · Practice questionSimple familiar1 mark
QUESTION 24
The histogram shows variation in a trait within a large population raised under similar conditions. Which pattern of inheritance is most consistent with the distribution?
(A)
A single fully penetrant recessive allele with two phenotypes.
(B)
Polygenic inheritance with contributions from several loci.
(C)
A Y-linked allele present only in males.
(D)
A mitochondrial allele with no variation.
WORKED SOLUTION
1 markAnswer B
Answer
B
Working
Several ordered phenotype categories with intermediate categories common are consistent with polygenic inheritance. A distribution alone does not prove how many loci are involved.
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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