Question

In the following food chain, only 2J of energy was available to the peacocks. How much energy would have been present in Grass? Justify your answer.

GRASS → GRASS HOPPER → FROG → SNAKE → PEACOCK

Answer 1

According to ten percent law, only ten percent of energy is transferred to each trophic level from the lower trophic level.

Total amount of energy from the snake = A = `"A" xx 10/100` = 2J

Or  A = 20 J

Total energy from the frog = B = `"B" xx 10/100 = 20`J

Or  B = 200 J

Total energy from the grasshopper,

C = `"C" xx 10/100` = 200 J

Or  C = 2000 J

Total energy from the grass,

D = `"D" xx 10/100` = 2000 J

Or  D = 20000 J

\[\ce{\underset{(20000 J)}{GRASS} -> \underset{(2000 J)}{GRASS HOPPER} -> \underset{(200 J)}{FROG} -> \underset{(20 J)}{SNAKE} -> \underset{(2J)}{PEACOCK}}\]

This means, the amount of energy present in the grass is 20000 J.