Question

In the following food chain, 20,000 J of energy was available to the
plants. How much energy would be available to man in this chain ?
Plants - sheep - Man

Explain with steps..

Is it 10 percentage will be awarded to each of next ? Am i right..

like

Sheep - 20000 X 10/100 = 2000

Man - 2000 X 10/100 = 200

Is it right or wrong ? if not why?

Answer 1

In the given food chain, plants are the producers and form the base of the food chain. The maximum energy obtained from sunlight is available to the plants. According to the 10% law of energy flow in a food chain, only 10% of the energy is transferred from one trophic level to another. Rest 90% of the energy is lost to the surroundings in the form of heat while some of it is used by the organisms for carrying out its life processes.

So, if 20000 J of energy is available to the plants, plants can utilise only 1% of energy. Therefore, plants have 200 J of energy with them.

Now, according to the 10% law,

Plants have 200 J of energy of which 20 J energy is transferred to the sheep.

Similarly,

Sheep have 20 J of energy of which 2 J energy is transferred to man.