Answer:
The correct answer is D
Step-by-step explanation:
The gen for hemophilia is located in the X chromosome, making the disease a sex-linked trait.
- A woman has 2 X chromosomes, so she can carry two copies of the H/h gene. If she carries the dominant allele H in one or two copies she will have normal blood clotting. If the woman has two recessive hh alleles, she will have hemophilia.
- A man only has one X chromosome (the other sex chromosme is a Y). If that chromosome has the H allele, he will not have the disease; if he has the h allele, he will be hemophilic.
The cross is between a heterozygous woman with a normal man:
x
- The woman produces two types of gametes:
and
- The man produces two types of gametes:
and
As a result of a Punnett Square, the expected offspring will be:
1)
: normal female
2)
: normal female, carrier of hemophilia
3)
: normal male
4)
: hemophilic male
The correct answer is D: one female normal, one male normal, one female carrier, one male with hemophilia