Answer:
D. guard cells.. this is answer i think..
What is part B I need more info.
Explanation:
Membrane proteins perform a variety of functions vital to the survival of organisms: Membrane receptor proteins relay signals between the cell's internal and external environments. Transport proteins move molecules and ions across the membrane. ... Cell adhesion molecules allow cells to identify each other and interact.
Human activities such as pollution , like trash , or boat oil can effect the waters that house 100 of creature and as for nitrogen cycle things like forest burning and fossil fuel combustion can result in the increased deposition of nitrogen from atmospheric sources
