Photosynthesis Question 31

31. Emerson’s enhancement effect and Red drop have been instrumental in the discovery of

[2016]

(a) photophosphorylation and non-cyclic electron transport

(b) two photosystems operating simultaneously

(c) photophosphorylation and cyclic electron transport

(d) oxidative phosphorylation

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Answer : b

Hints & Solution

(b) Emerson performed photosynthetic experiment. On Chlorella, he provide monochromatic light of more than $680 nm$ and observed decrease in rate of photosynthesis known as red drop. Later, he provides synchronised light of $680 nm$ and $700 nm$ and observed increase in rate of photosynthesis known as enhancement effect. This experiment led to discovery of two photosystems- PS-I and PS-II operating in photosynthesis.