Question
Hemophilia is a bleeding disorder that primarily affects males. Which of the following statements best explains why females are less likely to express the trait.
When paired with a normal X, the affected x allele is masked (Xx), suppressing the trait. Since females have only X alleles, the probability increases.
females have an XY chromosome pair, so the trait is frequently expressed.
males without an affected x allele always express the trait (XY)
when paired with a normal X, the affected x allele is masked (Xx), surpressing the trait. since females have only X alleles, the probability decreases.
When paired with a normal X, the affected x allele is masked (Xx), suppressing the trait. Since females have only X alleles, the probability increases.
females have an XY chromosome pair, so the trait is frequently expressed.
males without an affected x allele always express the trait (XY)
when paired with a normal X, the affected x allele is masked (Xx), surpressing the trait. since females have only X alleles, the probability decreases.
Answers
GPT-4o mini
The statement that best explains why females are less likely to express hemophilia is:
**When paired with a normal X, the affected X allele is masked (Xx), suppressing the trait. Since females have two X alleles, the probability decreases.**
This is because hemophilia is an X-linked recessive disorder. Males have only one X chromosome (XY), so if they inherit the affected X chromosome, they will express the trait. Females, on the other hand, have two X chromosomes (XX), so if they inherit one affected X chromosome, the normal X chromosome can mask the effect of the affected one, leading to a lower probability of expressing hemophilia.
**When paired with a normal X, the affected X allele is masked (Xx), suppressing the trait. Since females have two X alleles, the probability decreases.**
This is because hemophilia is an X-linked recessive disorder. Males have only one X chromosome (XY), so if they inherit the affected X chromosome, they will express the trait. Females, on the other hand, have two X chromosomes (XX), so if they inherit one affected X chromosome, the normal X chromosome can mask the effect of the affected one, leading to a lower probability of expressing hemophilia.
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GPT-4o mini
Yes, I'm confident in that explanation. Hemophilia is indeed an X-linked recessive disorder, which means:
1. **Males (XY)**: Males have one X and one Y chromosome. If they inherit the X chromosome carrying the hemophilia allele (Xᶦ), they will express the disorder because they do not have a second X chromosome that could potentially mask the affected allele.
2. **Females (XX)**: Females have two X chromosomes. If they inherit one affected X chromosome (Xᶦ) and one normal X chromosome (X), they will be heterozygous (XᶦX) and the normal X can mask the effects of the affected X. Therefore, they are less likely to express the disorder unless they inherit two affected X chromosomes (XᶦXᶦ), which is less common.
Thus, because females have two X chromosomes, the presence of one normal X can effectively suppress the manifestation of the hemophilia trait, making them less likely to express the disorder compared to males.
1. **Males (XY)**: Males have one X and one Y chromosome. If they inherit the X chromosome carrying the hemophilia allele (Xᶦ), they will express the disorder because they do not have a second X chromosome that could potentially mask the affected allele.
2. **Females (XX)**: Females have two X chromosomes. If they inherit one affected X chromosome (Xᶦ) and one normal X chromosome (X), they will be heterozygous (XᶦX) and the normal X can mask the effects of the affected X. Therefore, they are less likely to express the disorder unless they inherit two affected X chromosomes (XᶦXᶦ), which is less common.
Thus, because females have two X chromosomes, the presence of one normal X can effectively suppress the manifestation of the hemophilia trait, making them less likely to express the disorder compared to males.