If 50000 J energy available to primary producer, then energy available to tertiary consumer will be:
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → 50J
By the 10 per cent law, only about 10 per cent of the energy passes from one trophic level to the next. Producer 50000 J → primary consumer 5000 J → secondary consumer 500 J → tertiary consumer 50 J.
Option (1) 5J — Incorrect. 5 J would be the next level after the tertiary consumer.
Option (2) 50J — Correct. By the 10 per cent law, only about 10% of energy passes to each next trophic level. Producers 50000 J → primary consumers 5000 J → secondary 500 J → tertiary 50 J.
Option (3) 500J — Incorrect. 500 J reaches the secondary consumer.
Option (4) 5000J — Incorrect. 5000 J reaches the primary consumer.
NCERT Extract:
Energy Flow – “… The number of trophic levels in the grazing food chain is restricted as the transfer of energy follows 10 per cent law – only 10 per cent of the energy is transferred to each trophic level from the lower trophic level.”