Question

Rate of photosynthesis is dependent on ____________

• A. light quality
• B. light intensity
• C. duration of light
• D. All of the above

Answer 1

The correct option is D All of the above

The rate of photosynthesis is maximum when plants are exposed to blue and red regions of the visible spectrum as these wavelengths are absorbed by the chlorophyll. The rate of photosynthesis is minimum when exposed to green and other regions of the visible spectrum as these wavelengths are not absorbed by the photosynthetic pigments.
The rate of photosynthesis is affected by light intensity. When the light intensity is gradually increased from low intensity to high intensity, the photosynthetic absorption of
$C{O}_2$ and release of oxygen increases. This balances the gaseous exchange through cellular respiration thereby bringing the plant to the light compensation point. Beyond this point on further increasing the light intensity the photosynthetic release of oxygen increases.
The rate of photosynthesis is affected by the duration of light. Though continuous photosynthesis can occur in continuous illumination without any harm to the plant, the rate may slightly decline after 6 days. The rate of photosynthesis is also affected by temperature. A 10°C increase in temperature doubles the rate of photosynthesis up to an optimum temperature of 25°C.Beyond this temperature, the enzymes do not work efficiently as they undergo denaturation, thereby declines the rate of photosynthesis.