Question

Red drop phenomenon affects

• A. PS I.
• B. PS II.
• C. Accessory pigments.
• D. Chlorophyll.

Answer 1

The correct option is B PS II.

Since light wavelengths have been categorised into two groups. So the pigments affected by them are also divided into two; i.e., PS-I and PS-II. PS- I comprise p - 680, chlorophyll a - 695, p -700, chlorophyll - b and carotenoids whereas PS - II consists of chlorophyll a - 670, chlorophyll a - 690, chlorophyll b and phycobilin and therefore light is absorbed in PS-I at 700 and in PS-II at or just below 680. If wavelength used is beyond 680 nm PS-II will not function, as this happens in the region of red light, it is called the red drop phenomenon.