Auxin is the molecule which is related to the phototropism of the plants. In the mutant plants, which do not have hormone auxin, do not respond to light. It activates proton pump, and leads to the decrease in the pH of the leaf. This acidification breaks cell wall structure and cell wall become less rigid, and thus, can bend towards the light, by exerting mechanical pressure.
Answer:
B.The water is drawn into the ground by the force of gravity.
<span>As there are many kinds of deserts, some hot, some cold even arid deserts are the classic hot deserts, but there are also cold and coastal deserts where temperatures do not get so high. The element common to all of these types of deserts, however, is their lack of rainfall. In that sense the rainfall is a characteristic that determines if it's a desert.</span>
