Question

In the food chain given below, if the amount of energy available at fourth trophic level is 5 kJ, what was the energy available at the producer level?
Grass → Grasshopper → Frog → Snake → Hawk
(a) 500 kJ
(b) 50 kJ
(c) 5000 kJ
(d) 5 kJ

Answer 1

(c) 5,000 kJ

According to the 10 per cent law, only 10 per cent of the energy available in a trophic level is passed on to the next level. Hence, if the amount of energy available at the fourth trophic level is 5 kJ, the energy available at the producer level will be 5,000 kJ: 5 → 50 → 500 → 5,000.