A man and woman carry allele for PKU disease they dont have the disease what is the chance of thier child hav?

a).25 b).50 c) .75 d)1.00

6 Answers

  • 1 decade ago
    Favorite Answer


    The alleles are P and p with PP being normal, Pp being carrier and the homozygous autosomal recessive pp being Phenylketonuric (PKU)

    Both parents are Pp carriers.

    Hence each of them donate a P and a p gene

    Their children will have

    25% chance of PP

    50% chance of Pp

    25% chance of pp

  • 1 decade ago

    Definately answer A. Use a punnett square and assume that the allele for PKU is recessive (pp).

    P p

    P PP Pp

    p Pp pp

    The chance that the first generation offspring will have the gene for PKU is 25% .

  • 1 decade ago

    A 25% LETS SAY THAT THE ALLELE FOR NORMAL IS N AND FOR THE DISESE IS p IF BOTH PARENTS ARE Np AND YOU CROSS THEM THEM YOU GET 25% NN or no disese and 50% Np which would be carriers and 25% pp which would show the symptoms of the disese

  • 1 decade ago

    It's a 25%(a) chance that they will get it and I believe 75% that they will carry it.

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  • 1 decade ago


    if they carry the allele but don't have the disease, it must be recessive aka both carry Aa

    Aa x Aa = AA, Aa, Aa, and aa (aa is the only kid that will have the disease)

  • 1 decade ago

    50 %

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