Answer:
the answer is biochemistry
The answer is B .
Biotic factor refers to living things .
The main food sources of the birds( the plentiful recourses within the environment occupied by the species)
I would say immigration only.
emigration would theoretically reduce the genetic variation as unique individuals leave, but immigration would bring unique traits into circulation in an ecosystem.
I'm not super great at biogy tho so this might not be right... :)
B cells mature in the bone marrow, which is at the core of most bones It recognises invaders by the shape of molecules -antigens- on their surfaces. With the help of T cells, B cells make proteins called antibodies. The antibodies will help your body become aware of intruders.
