I: | The whole scheme of transfer of electrons, starting from the PS II, uphill to the acceptor, down the electron transport chain to PS I, excitation of electrons, transfer to another acceptor, and finally down-hill to NADP+ reducing it to NADPH + H+ is called the Z scheme. |
II: | The electrons that are moved from photosystem II get replaced by electrons available due to splitting of water. |
1. Only I | 2. Only II |
3. Both I and II | 4. Neither I nor II |