It gives the characteristic trait of the organisms that can be good or bad to the survival of it environment. But to go into depth as each organisms die and the survival of each one reproduce it will come out as a natural selected to the survival of the environment aka Survival of the Fittest. :)
There is a 50% probability that the child will be a boy. If this is the case, he will inherit the X chromosome from his mother and the Y chromosome from his father. Since the woman has DMD, the boy will certainly inherit the disease, since he only has one X chromosome and it carries the disease. We know that both of the mother's X chromosomes carry the disease because since it is recessive, both of her chromosomes must have it in order for her to have it.
There is also a 50% probability that the child is girl. If this is the case, she will inherit a normal X chromosome from her father and the disease-carrying X chromosome from her mother. Since the disease is recessive, she will not be affected by the disease, since she has one healthy X chromosome and one disease-carrying one.
If the child is a girl, there is a 0% chance that she will have the disease (although she will be a carrier).
If the child is a boy, there is a 100% chance that he will inherit the disease.
The answer is D)
The answer is 1 because as you move farther from the center of the earth gravity would have less of an effect on you
