Explain why most food chains are restricted to four or five steps.

B2. Explain why most food chains are restricted to four or five steps. Or In a food chain explain why the number of trophic levels are seldom more than four and five. Ans. During the transfer of energy through successive trophic levels, only 10 per cent of energy is available for the transfer to the next trophic level. If the food-chain consists of more than 5 trophic levels, then a negligible [Dec-2011, Q.No.-1(c)(i)1

amount of energy is insufficient for its survival . Hence , most food chainst are restricted to four or five steps , e . g . Grass Grasshopper Insects Frogs Snakes Hawks - 1000J 100J10J 1 0 . 1J 0 . 01J