Species A’s population will decrease due to limited space. <em>(I think. I'm sorry if I'm wrong.)</em>
Allergies because they are the only disorder listed that is a result of the environment.
So
step 1 is: H= normal h= hemophilia
Step 2 is: HH x hh
Three:
All of there offsprings would be Hh 100%
The food chain would most likely collapse slowing, without a producer other animals cannot get the needed nutrients required to survive.