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NEET2013ZoologyPrinciples of Inheritance and VariationActual

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

Options

  1. AIn family A , both the parents are homozygous recessive.
  2. BIn family B , both the parents are homozygous dominant.
  3. CIn family B , both the parents are heterozygous recessive.
  4. DIn family A , both the parents are heterozygous recessive.

Correct answer

D. In family A , both the parents are heterozygous recessive.

Step-by-step solution

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.

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