Answer:
Cohesion and adhesion of water molecules
Explanation:
Cohesion has to do with the ability of water to adhere together .
The cohesive properties of water which is occasioned by hydrogen bonding between adjacent water molecules allow the column of water to move up through the plant irrespective of the force of gravity as water molecules are evaporating at the leaf surface.
The adhesive properties of water, which means, the attraction between the water molecule and the xylem wall also ensure continuity in the movement of the water column in the xylem.
Hence the cohesive and adhesive properties of water molecules are important for transpiration to occur.
A change in the contolled veriable. Such as a color change, state of matter change, a reaction like oader, bubbling or tempature change.
