China Naming Network - Solar terms knowledge - (20 13? Liaocheng Yimi) is a pedigree chart of a family with two genetic diseases. If I-2 has no B disease gene, the following statement is wrong: () A.
(20 13? Liaocheng Yimi) is a pedigree chart of a family with two genetic diseases. If I-2 has no B disease gene, the following statement is wrong: () A.
A, according to the parents' illness and normal children, it can be judged that A is an autosomal dominant genetic disease and A is correct;
The probability that B and II-3 are homozygotes is1/3x1/2 =1/6, and B is correct;
C, because I-2 has no B-disease gene and No.6 has B-disease, B-disease is an X-chromosome recessive genetic disease, genotype II-4 is AAXBXBXBXBXBBB or AAXBXBXBXBXBBB, and the probability of being a heterozygote is 1/2, so C is wrong;
D If II-4 marries a normal male, the probability of giving birth to a normal boy is 3/4× 1/2=3/8, and D is correct.
So choose C.