Imagine that a newly discovered, recessively inherited disease is expressed only in individuals with type o blood, although the disease and blood group are independently inherited.
a normal man with type a blood and a normal woman with type b blood have already had one child with the disease. the woman is now pregnant for a second time.
assuming that both parents are heterozygous for the gene that causes the disease, what is the probability that the second child will also have the disease? express your answer as a fraction using the slash symbol and no spaces (for example, 1/2).

Mr. j, age 42, is a construction worker in las vegas. he recently noticed that a mole on his face seemed to be getting larger and darker. at first he did not worry because he was in the sun a lot and assumed the change may have been caused by sunburn. after a month, not only was the mole larger and darker, but it appeared to be “bumpy.” his doctor diagnosed a malignant melanoma skin cancer following biopsy of the nevus. mr. j reports pain in his right shin that does not go away when he puts his feet up or sleeps. discussion questions 1. relate mr. j’s skin changes to the warning signs for malignant melanoma. (see malignant melanoma.) 2. discuss the normal progression of this malignancy. what is the significance of the bone pain that mr. j is experiencing? (see malignant melanoma.) 3. discuss the treatment available for this patient and the prognosis for recovery. (see malignant melanoma.)