Hemophilia is an bleeding disorder where blood dose not clot properly. This disorder is caused ny a recessive allele on the X chromosomr. A couple has just learned that their daughter has hemophilia. They already have a son who dose not have a disease. What are the genotypes of the couple and the two siblings? Explain your answer.
no he's my baby
No, he is really all of ours
To determine the genotypes of the couple and their two children, it is important to understand the inheritance pattern of hemophilia. Hemophilia is caused by a recessive allele on the X chromosome, meaning it is sex-linked.
Given that the couple has a daughter with hemophilia and a son without the disease, we can make the following inferences:
1. Daughters inherit one X chromosome from their mother and one from their father.
2. Sons inherit one X chromosome from their mother and one Y chromosome from their father.
Let's assign some variables for convenience:
- The mother will be denoted as "X^aX^a" (where X^a represents the normal allele)
- The father will be denoted as "X^AY" (normal allele on the X chromosome and a Y chromosome)
- The daughter with hemophilia will be denoted as "X^aX^A" (one normal allele, one hemophilia allele)
- The son without hemophilia will be denoted as "X^AX^Y" (normal allele on both X chromosome and a Y chromosome)
Explanation:
- Since the daughter has hemophilia, she must have inherited the hemophilia allele from her father and a normal allele from her mother. Therefore, her genotype is "X^aX^A".
- The son does not have hemophilia, meaning he received a normal allele from his mother. Thus, his genotype is "X^AX^Y".
- Given that the daughter's genotype is "X^aX^A" and the son's genotype is "X^AX^Y", we can deduce that the mother must be a carrier for hemophilia since she passed the hemophilia allele to her daughter but not to her son. Her genotype is "X^aX^a".
- The father must have a normal allele on his X chromosome since neither he nor his son has hemophilia. Therefore, his genotype is "X^AY".
In summary:
- The mother's genotype is "X^aX^a" (carrier for hemophilia)
- The father's genotype is "X^AY" (normal allele on the X chromosome)
- The daughter's genotype is "X^aX^A" (carrier for hemophilia)
- The son's genotype is "X^AX^Y" (normal alleles on both X chromosome and Y chromosome)