Question

In a food chain there are four organism: grass, bird, grasshopper and cat. If the grass contains 1,250,000 calories, how many of these calories would be available to the grasshopper, birds and cats? Assume that grasshoppers feed exclusively on grass, birds feed exclusively on grasshoppers and cats feed exclusively on birds.

Answer 1

the food chain is as follow ATQ

grass - grasshopper - birds - cats

according to the 10 % law i.e. that only 10 % of the energy  would be passed on from trophic level to the other

therefore ,

4.184cal = 1kj(unit of energy)

after the conversion the amount of energy present in grass would be

1250000 * 4.184 = 5230000 kj

grass = 5230000 kj

therefore ,

grasshoppers would get 10% percent of it = 523000 kj

birds = 52300 kj

cats =  5230 kj