Which of the following is true for a recessive disease in family A and B?

Question

Which of the following is true for a recessive disease in family A and B? (A) In family A, both the parents are homozygous recessive. (B) In family B, both the parents are homozygous dominant. (C) In family B, both the parents are heterozygous recessive. (D) In family A, both the parents are heterozygous recessive.

Tardigrade Admin · Accepted Answer

In family A, if both the parents are homozygous recessive, then both should be diseased and should have 100% diseased progeny. In family B, if both parents are homozygous dominant, they would not have got the recessive disease in first place. In family B, if both are heterozygous recessive, then also they would not have got the disease, neither 80% of progeny would be diseased.

Q. Which of the following is true for a recessive disease in family A and B?

In family A, both the parents are homozygous recessive.

In family B, both the parents are homozygous dominant.

In family B, both the parents are heterozygous recessive.

In family A, both the parents are heterozygous recessive.