The xanthophyll cycle, which comprises the three carotenoids violaxanthin, antheraxanthin, and zeaxanthin, establishes an ability to dissipate excess light energy in the leaf, Under high light the conversion of the carotenoids such as

#Question id: 10226

#Unit 6. System Physiology – Plant

Under moderate excess light Quantum efficiency decreases , but the maximum photosynthetic rate remains unchanged and caused by the diversion of absorbed light energy toward heat dissipation—hence the decrease in quantum efficiency this term is known as

#Question id: 10227

#Unit 6. System Physiology – Plant

The evaporation of water requires energy, when water evaporates from a leaf (transpiration), it removes large amounts of heat from the leaf and thus cools it. The human body is cooled by the same principle, commonly known as

#Question id: 10228

#Unit 6. System Physiology – Plant

Photorespiration and the quantum yield differ between C3 and C4 photosynthesis, with changes particularly noticeable as temperatures vary quantum yield for photosynthesis as a function of leaf temperature in C3 plants and C4 plants. Following are some statements  based on this study.

 a.) In the C4 plants the quantum yield remains constant with temperature, reflecting low rates of photorespiration

 b.) At lower temperatures the quantum yield of C3 plants is higher than that of C4 plants

c.) C3 photosynthesis is more efficient at lower temperatures

 d.) At higher temperatures the quantum yield of C3 plants is higher  than that of C4 plants

 Which one of the following combination of above statements is correct?

#Question id: 10229

#Unit 6. System Physiology – Plant

Comparing such a plot for C3 and C4 plants reveals differences between the two pathways of carbon metabolism, which of the following given statements will be incorrect?

#Question id: 19069

#Unit 6. System Physiology – Plant

#Question id: 27357

#Unit 6. System Physiology – Plant