Question

A recessive allele inherited in a Mendelian manner causes the disease cystic fibrosis. A phenotypically normal man whose father had cystic fibrosis marries a phenotypically normal woman from outside the family. If the frequency in the general population of heterozygotes for cystic fibrosis is 1 in 50, what is the chance that the couple's first child will have cysitc fibrosis

Answer 1

The chance that the couple's first child will have cysitc fibrosis is equal to
`0.005`

Step-by-step explanation:

The probability of man having cystic fibrosis is equal to
`100` percent

The probability of his wife having cystic fibrosis is equal to
`(1)/(50)`

In case if both have them allele for cystic fibrosis, then the probability of their children having a child with cystic fibrosis

`(1)/(4)`

The chance that the couple's first child will have cysitc fibrosis is equal to

`1* (1)/(50) *(1)/(4) \\= (1)/(200)\\= 0.005`