This is called the nacreous layer, the pearly layer.
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:
genetic recombination
Explanation:
Bacteria and other harmful organisms like viruses infect people rapidly with genetic recombination.
Hope it helps.