The answer is energy. In order to grow and develop, all of life must be able to use energy to sustain the source of life. The ability to reproduce, grow and develop are defining features of life. Organisms use energy to maintain their metabolic processes.
This is where diffusion happens down the concentration gradient i.e. from high to low concentrations (just like simple diffusion) but facilitated diffusion requires a special and specific protein within the cell membrane. The substate binds to the receptor and the receptor itself changes conformation so that the substrate is now on the other side of the membrane. This is done for molecules that are too large to pass straight through the phospholipid bilayer (cell membrane) by simple diffusion e.g. glucose.
Answer: Didn't quite understand but if you mean plant biology then, ' Plant biology is the lab science area of plant study although they may spend some time in the field collection samples and taking records of plants in their natural habitats. It requires not only an understanding of a plant's biology but also its chemistry. This will include its genetic coding.'
