Solution

The PS II reaction centre absorbs maximally at 680 nm ($P_{680}$).

In PS I the reaction centre chlorophyll a has an absorption peak at 700 nm, hence is called $P_{700}$, while in PS II it has absorption maxima at 680 nm, and is called $P_{680}$.

Concept P680 reaction centre

Photosynthesis in Higher Plants in past papers

91 questions from this chapter have appeared across 26 exam years.