To determine the genotype of a female carrier of hemophilia, it is important to understand the genetic basis of hemophilia. Hemophilia is a sex-linked recessive disorder, which means that the genetic information responsible for the disorder is located on the X chromosome.
In terms of notation:
1. [tex]\( X^H \)[/tex]: This represents the normal allele for clotting factor.
2. [tex]\( X^h \)[/tex]: This represents the allele for hemophilia, indicating the recessive trait.
3. [tex]\( Y \)[/tex]: This represents the Y chromosome, which does not carry any allele for hemophilia because the disorder is X-linked.
To identify the genotype of a female who is a carrier of hemophilia:
- A female has two X chromosomes.
- For her to be a carrier, she must have one normal allele and one allele for hemophilia. This means she has one [tex]\( X^H \)[/tex] and one [tex]\( X^h \)[/tex] allele.
- Carrier means she shows no symptoms of hemophilia herself but can pass the hemophilia allele to her offspring.
Given these points, let's examine the provided options:
- [tex]\( X^H X^h \)[/tex]: This corresponds to a female with one normal blood clotting allele and one hemophilia allele, making her a carrier.
- [tex]\( X^h X^h \)[/tex]: This would signify a female with two hemophilia alleles, meaning she would have hemophilia.
- [tex]\( X^{H} X^{H} \)[/tex]: This would be a female with two normal alleles, meaning she would not be a carrier or affected by hemophilia.
- [tex]\( X^H X^h Y \)[/tex]: This genotype is not possible because it includes both two X chromosomes and a Y chromosome, which does not occur in typical human genotypes. Additionally, the presence of a Y chromosome would indicate a male.
Thus, the correct genotype for a female carrier of hemophilia is:
[tex]\( X^H X^h \)[/tex].
