Question

Define the following:
(i) Plant pigments
(ii) Quantum
(iii) Organic food
(iv) Light reaction
(v) Photolysis in photosynthesis

Answer 1

(i) Plant pigments: The coloured pigments in plants that absorb light of different wavelengths are called plant pigments. Example: Chlorophyll, xanthophyll, etc.

(ii) Quantum: It is the basic unit of light. One quantum is equivalent to one photon.

(iii) Organic food: The food produced using the methods of organic farming and without the use of chemical fertilisers is called organic food.

(iv) Light reaction: The reaction that takes place inside the chloroplast ​grana and in the presence of light is called light reaction. It involves absorption of light and splitting of water.

(v) Photolysis in photosynthesis: The breaking down of water into oxygen and hydrogen ions during a light reaction is known as photolysis.