what is the effect of uncoupling photosystem 1 from photosystem 2 on the hill reaction and why? how can this be used to develop chemical herbicides? how can this be used to study the relative reaction rates of each photosystem independently? can oxygen production be used to measure photosynthetic activity? would oxygen be produced in the presence of chemical uncouplers such as DCMU? a white light source was used in this experiment. would you expect to find photosynthetic activity at all wavelengths? why or why not?