The model illustrates a process by which a substance is taken up by a cell

an active site is a region that is present on an enzyme where the reactants or the substrate molecules we can say bind and experience a chemical reaction. the substrate is basically a reactant whose concentration is changing and that is converting into a product after binding at the active site of an enzyme

the answer is "a.) well–developed vascular system."

explanation:

true skin; another name for the dermis. lies directly beneath the epidermis and is often referred to as the true skin. outermost layer of epidermis, consisting of dead cells.