The causitive agent of the cohesion-tension model of xylem transport is transpiration. During the process of transpiration, water vapor is lost from the stomata of the leaf. To replace this water, water from adjacent cells is withdrawn. The water molecules stick together due to cohesion and are transported upwards through the stem in the form of a stream.<span />
D. This is because artificial selection is basically the human breeding of plants or animals, and we do so in a way to bring forth the best traits to solve a problem or create a better product. Hope this helps!
