In humans, the ability to taste PTC is dominant over non-tasting. Two heterozygous tasters have three children. What is the probability that one or more of the children will be non-tasters?

a. 0.684

b. 0.578

c. 0.251

d. 0.422

e. 0.004

 

I assumed that the two heterozygous parents would have a 1/4 chance of passing on the recessive, non-tasting gene, aa. With three children, I would think to use the product rule, thus multiplying (1/4)(1/4)(1/4)= 1/64 = 0.0156

 

Please help explain what I have done wrong. Thank you.

it should be .251.(1/4)

what you did is correct when he asks about probability of first three children being non tasters.but he is asking only about one or more children.he gave no. of children just to confuse you.