As leaf temperature increases from 20C to 35C the quantum yi

As leaf temperature increases from 20°C to 35°C, the quantum yield of C3 photosynthesis is directly affected by

The decreasing ratio CO2 to O2 in the gas phase

The increased reaction rates of photorespiration

The decreasing ratio CO2 to O2 in the aqueous phase

Degradation of the thylakoid membrane and proteins

RubisCO’s improved affinity for O2.

Solution

Answer is :

The decreasing ratio CO2 to O2 in the aqueous phase.

Reason: When the leaves are hot, CO2 becomes less soluble in the aqueous phase faster than O2, and the CO2/O2 ratio drops