6 is the answer to this
hope it helps
Any substance that triggers an immune response is an antigen(s).
The Answer -
A. The amount of land available for lumber production decreases.
Do to the Urban development there is fewer land and less trees to grow and cut down for lumber, which can lead in a decrees if production for lumber.
I think its a density dependent limited factor
Type 1 Diabetic here! I can help!! so basically the receptor for insulin is a large protein that binds to insulin and passes its message into the cell. It has several functional parts. Two copies of the protein chains come together on the outside of the cell to form the receptor site that binds to insulin.
I hope this helped :)