Biology for IGCSE & O level - Inheritance (Section 8 - No. 37)
In an X-linked recessive disorder, which parent(s) must contribute the affected allele for a daughter to express the disorder?
Only the father.
Only the mother.
Both the mother and the father.
Either the mother or the father.
Uitleg
A daughter must inherit two copies of the affected allele, one from each parent, to express an X-linked recessive disorder.