The palisade mesophyll has long cylinder shaped cells, lots of chloroplasts, cells closely packed together and large size of cells.
The correct option is THE ELECTRON IN THE OUTERMOST ELECTRON SHELL.
Different levels of energy exist in the atom of an element and these levels are filled with electrons. The electrons in the innermost shell has the lowest energy level while the electrons in the outermost shell has the highest energy level. For an electron to increase its energy level, it has to move to an higher shell; and to decrease its energy level it has to move to a lower shell.
B, hormones that serve as chemical messengers im not 100% sure though
