Question

Question 9 1 pts Hemophilia is a sex-linked trait. Assuming a 1:1 sex ratio, how many hemophilia alleles (both wild-type and disease-causing) are found in a population of 100 people. 50 150 250 100 O 200

Answer 1

Correct answer is option B -150

Hemophilia is a X linked recessive disease.

Disease is caused when the person have the disease causing gene on the X chromosome.

Diseased female,both the X chromosome will be defective .

Carrier female will have one disease x chromosome and a normal wild type X chromosome .

Hemophilic male will have one diseased X chromosome and a normal Y chromosome.

Here there is a population of 100 people.in which the sex ratio is 1:1.it means that the half of the population is male and other half is female.

Number of male =1/2 *100 =50

Number of female = 1/2 ×100 =50

The sex chromosome of the male is XY .

so the number of X allele from male is 50 and number of Y allele is 50.

The sex chromosome of the female is XX.

so the number of X allele from the female is 2*50=100.

Hence the total number of X allele in this population =number of x allele from male + number of X allele from female =50 +100 =150.

In this the some of the X chromosome will be disease causing and some of them will be normal wild type.

So the number of Wild type allele + number of diseaee causing allele =150.