What structure is part of an echinoderms water vascular system?

The water vascular system controls the tube feet hydraulically through a complex of fluid filled canals and reservoirs. Unlike other echinoderms, the madreporite of the holothuroideans is located internally below the pharynx and opens to the coelom instead of the outside world.

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) cell division.

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