Mostly during the summer, July would be the best month to see them.
Centrioles is only found in animal cells but not in plant cells.
Answer:
a. In the presence of 2,4 dinitrophenol, which is soluble through the lipid membranes, the H+ gets an another route to pass through the membrane. It hampers the proton gradient potential without any generation of ATP. The gradient that was being utilized for the generation of energy is now just lost in the form of heat.
b. With the reduction in the generation of energy, the cells get devoid of ATP, and drive the electron transport chain intensely so that the collapsing proton gradient gets re-established. However, it prevents the ATP synthase by providing a different path to the proton ions and thus diminishing the H+ concentration gradient.