I hope you get your answer soon! :)
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.
Direct effects, as the name suggests, while not manipulated or communicated by a third party, deal with the direct influence of one entity on another. Indirect effects can be described as the influence, mediated or passed on by a third, of one organism or species on another.
they can mate with grizzlies