This would be a recessive disease.
Father is dd
Mother is Dd (has to be because one child has the disease)
Parents cross is dd x Dd which gives rise to Dd (0.5) and dd (0.5). Each time they have a child they have a 50% chance of the child having the disease. In their case, only one of their 3 children is dd. The others though are carriers!
A deeper study into the virus itself
Sometimes they're used as drugs. The classic example might be penicillin, a compound made by a fungus and used as the first widely-available antibiotic.
Answer:
Force is a measure of power. Velocity, on the other hand, is a quality an object has. Apply force to an object, and its velocity changes.
Answer:
The differential equations and the boundary conditions(initial and final)are shown in the attachment
