Adhesion is the process of attaching one thing to another. For plants, adhesion allows for the water to stick to the organic tissues of plants. Cohesion keeps molecules of the same substance together. For plants, cohesion keeps the water molecules together. Surface tension is the effect of intermolecular attraction that causes liquids to form a top or outer layer that behaves like a thin film of sorts. Surface tension is responsible for the shape of water drops and for holding the structures together as plants soak up the water.