Can YOU help me with these 2 science questions?

Question

1) How do the cells of people with Diwn syndrome differ from those of others? How might the difference arise?

2) A couple with a family history of hemophilia is about to have a baby girl. What information about the parents would you want to know? How would this information help you determine whether the baby will have hemophilia?

Answer 1

1. I am unaware of Diwn syndrome. In Down syndrome, there are three of chromosome 21. Some of the genes on that chromosome are involved in the expression of the structural proteins that go into the Down's phenotype.

2. I would want to know about the family history on both sides, since the allele is X-linked recessive for hemophila A. If the father does not have the disease, the daughter at most will be a carrier, and asymptomatic. For the daughter to have the disease, the mother would have to be a carrier or actually have the disease, and the father must have the disease.

Answer 2

1. People with Down syndrome have an extra copy of chromosome #21 -- results from nondisjunction.

2. Does the Dad have hemophilia? If he doesn't, then no daughters will have hemophilia. The gene for hemophilia is on the X-chromosome and it's recessive. Any girls will get the X with the gene for normal clotting from their Dad.