To determine the genotype of a male hemophiliac, we need to understand the genetic inheritance of hemophilia and how it is expressed in males.
Hemophilia is a sex-linked disorder carried on the X chromosome. For males, who have one X and one Y chromosome (XY), the presence of a single affected X chromosome (hemophilia allele) will result in hemophilia because they lack a second X chromosome that could potentially carry a normal allele.
Given:
- [tex]\( X ^{ H } \)[/tex] denotes the normal allele on the X chromosome.
- [tex]\( X ^{ h } \)[/tex] denotes the hemophilia allele on the X chromosome.
- [tex]\( Y \)[/tex] represents the normal Y chromosome.
Let's analyze the given options:
1. [tex]\( X^H Y \)[/tex]:
- [tex]\( X^H \)[/tex] is a normal X chromosome, and [tex]\( Y \)[/tex] is a normal Y chromosome.
- This genotype would result in a normal male with no hemophilia because there is no hemophilia allele present.
2. [tex]\( X^h Y \)[/tex]:
- [tex]\( X^h \)[/tex] is a hemophilia allele on the X chromosome, and [tex]\( Y \)[/tex] is a normal Y chromosome.
- This genotype would result in a male with hemophilia because the single X chromosome carries the hemophilia allele and there is no normal X chromosome to offset it.
3. [tex]\( X^h Y^h \)[/tex]:
- This notation is incorrect because males only have one X and one Y chromosome.
- They cannot have a second Y chromosome, making this option invalid.
4. [tex]\( X^h Y^{\dagger} Y \)[/tex]:
- This notation introduces a superscript [tex]\(\dagger\)[/tex] and an additional Y chromosome, which is biologically not possible for a normal male.
- Males have one X and one Y chromosome, making this option invalid.
After careful consideration of the options, the genotype that correctly represents a male hemophiliac is:
[tex]\[ X^h Y \][/tex]
Thus, the correct answer is option 2: [tex]\( X^h Y \)[/tex].
