1.)A couple has just learned that their daughter has hemophilia. They already have a son who does not have the disease. What are the genotypes of the couple? Explain your reasoning.
ANWSER:They are both likely carriers of the disease, therefore they'd have the recessive gene somewhere but not on both chromosomes of the homologous pair.
Am im correct?!
Not correct. the keyword here is Daughter. Hemphilla both types, A and B, are carried on the X genes. So if it had been a son who had the disease, you would be correct.
However, daughters carry two X chromosomes, one from Mom, and one from Dad. We have bad news for Mom, if daughter has type A or B hemophilia, Mom has the defective gene on her one X, and it is likely she will get hemphilia.
But if Mom has no symptoms, then it well may be Type C hemophilia, which is non sex linked. The first question to be asked are mom and dad ews of Ashkenazi (east European) descent. If so, then your original answer is probably correct.
Life is not always simple. Females have XX gentoype, and males have XY. Sons get one x from mom, and the Y from dad. Daughters get an X from both parents.
Daughters getting hemophilia is so rare, if I were the physician, I think I would order a genetic test of daughter and parents to verify that in fact the couple is the genetic parents. If sex linked, Mom has to have a defective gene...
Not my thing, sorry but based on what little I remember that sounds correct.
Thanks
To determine the genotypes of the couple, we need to understand the inheritance pattern of hemophilia.
Hemophilia is an X-linked recessive disorder, which means that the gene responsible for the disease is located on the X chromosome. Females have two X chromosomes (XX), while males have one X chromosome and one Y chromosome (XY).
Based on the given information that the couple has a daughter with hemophilia and a son without hemophilia, we can conclude the following:
1. The daughter has hemophilia, which means she must have inherited the disease-causing gene from both her parents. Since the father is unaffected and does not have hemophilia, we can conclude that he must have provided a healthy copy of the X chromosome to his daughter.
2. The son does not have hemophilia, which means he received a healthy copy of the X chromosome from his mother. If the son had received the X chromosome with the hemophilia gene, he would have developed the disease.
Given these facts, we can infer that both parents are carriers of the hemophilia gene. This means that they each have one copy of the gene on one of their X chromosomes. Because they are carriers, they do not have the disease themselves, but they can potentially pass it on to their children.
Therefore, the genotypes of the couple can be represented as follows:
- Mother: XhX (carries the hemophilia gene on one X chromosome)
- Father: XHY (does not carry the hemophilia gene)
It is important to note that this is a simplified explanation, assuming that the couple's daughter's hemophilia is solely due to the hemophilia gene and not any other genetic factors. Consulting a healthcare professional or genetic counselor would provide a more accurate assessment.