Prelims 2014 · archive
EasyWhich one of the following is the process involved in photosynthesis?
Answer & explanation
Answer: (b) Free energy is converted into potential energy and stored
In photosynthesis, green plants capture free energy from sunlight and convert it into chemical energy. That energy is stored in carbohydrates as potential energy. This matches option (b).
- ✗ (a) This describes the release of stored energy, as in respiration or burning of food. Photosynthesis does the opposite and stores energy.
- ✓ (b) Chlorophyll absorbs light energy. This is converted to chemical energy and stored in carbohydrates made by reducing carbon dioxide, using hydrogen from split water molecules.
- ✗ (c) Oxidation of food to release carbon dioxide and water is respiration. Photosynthesis uses carbon dioxide and water to build food.
- ✗ (d) Taking in oxygen and giving out carbon dioxide and water vapour is the gas exchange of respiration. In photosynthesis, carbon dioxide is taken in and oxygen is released.
Remember · Photosynthesis stores light energy as chemical (potential) energy in carbohydrates and releases oxygen. Respiration is the reverse: it oxidises food and releases energy, carbon dioxide and water.
📘 Read it in NCERT: Class 10 Science, Ch 5 (practise this chapter) · Class 10 Science, Ch 13 (practise this chapter)
Sources
- NCERT Class 10 · Science, Chapter 5 “Conversion of light energy to chemical energy and splitting of water molecules into hydrogen and oxygen. (iii) Reduction of carbon dioxide to carbohydrates.”
- NCERT Class 10 · Science, Chapter 13 “the autotrophs capture the energy present in sunlight and convert it into chemical energy. This energy supports all the activities of the living world.”
Question: UPSC Civil Services (Preliminary) 2014, General Studies paper. Explanation: Minimalist IAS, checked 25 Oct 2026 (how we verify). ·