Answer:
The given blank can be filled with chlorophyll.
Step-by-step explanation:
The reactions of photosynthesis take place in the thylakoid membranes where chlorophyll is present. In the process, two sets of light absorbing reactions and two sets of electron transport reactions are involved. In stage 1 of photosynthesis, light hits photosystem II (P680) in the chlorophyll resulting in the boosting of the electrons to a higher energy level and passing them further into the electron transport chain.