Answer:
B..........................
The circulatory aids with the immune system because they provide white-blood cells to help fight with the diseases or sicknesses.
B. One
because an independent variable is something you change. So in a scientific experiment you only change one thing. If you happen to change more than one thing then the test becomes unfair therefore you should repeat and make sure that only one thing is changed this time.
1.) Achodroplasia is a autosomal dominant disorder, the suspected case suggested that inorder for the parents to produce and offspring with achondroplasia. One parents must have a single mutant gene of achodroplasia to be inherited by his offspring. for this case, It is suggested that the offspring might have developed its own mutant gene as it only affect 1 in 25,000 birth. There is changes of genes during early development.
2.) The mother said that they don't have that history of disorder. again, it's autosomal dominant disorder. one parents must have that kind of disorder so their child can also inherit it. Thus, no of the childs parents is a carrier.
