In order for a child to develop cystic fibrosis,
A. genetic recombination must occur in the mother but not the father
B. more than one egg in the mother must carry the CF allele
C. more than one sperm in the father must carry the CF allele
D. a sperm carrying a CF allele must fertilize an egg that also has that allele
E. genetic recombination must occur in the father but not the mother
Answer (1)
A child develops cystic fibrosis when a sperm carrying a CF allele successfully fertilizes an egg that also carries a CF allele. This inheritance requires both parents to pass on a copy of the mutated CF gene, demonstrating autosomal recessive inheritance. As such, it's crucial that both alleles are present for the child to manifest the disease. ;
