Question
Cystic fibrosis is caused by a recessive allele (f). Two parents who are both carriers (Ff) plan to have a child.
(a) Complete a Punnett square for the cross Ff × Ff. (2 marks) (b) State the probability that the child will have cystic fibrosis. (1 mark) (c) Explain why two unaffected parents can have an affected child. (3 marks)
6 marks · take your time before peeking.
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Generated by TopMyGrade AI · cross-check official sources before relying on the mark-scheme phrasing.