Necessary conditions for photosynthesis in Hydrilla-
1. Chlorophyll that absorbs solar energy and converts it into chemical energy.
2. Water, which is taken by aquatic plants through thin epidermis of their body surface.
3. Sunlight which is absorbed by pigments molecules and is converted into chemical energy.
4. Carbon-dioxide which enters through general body surface in aquatic plants.
5. Suitable temperature.