Describe the effect of light on physiology of plants.

Explanation

Importance of light to plants. Light is essential for life. Light influences the plants in many ways. (i) Source of energy. Green plants trap sunlight to manufacture food by photosynthesis. They provide food and O2 to the other animals directly or indirectly (ii) Photoperiodism. Duration of light hours play an important role in flowering and growth of plants. Duration of daylight determine the time of flowering (iii) Synthesis of plant pigments-chlorophylls and carotenes. Moderate light produces bright green leaves while strong light scorches the leaves (iv) Plant movement. The leaves of leguminous plants fold-up or droop at night -nyctinastic movements. Plants bend towards source of light (v) Distribution of plants. Light affects the distribution of plants/flora e.g., planktons are confined to 200 metre deep strata of water because no light, no photosynthetic organisms occur beyond this depth (vi) Light directly affects the growth of plants by synthesis of hormones, opening and closing of stomata etc.