Ecosystem

Biology · Class 12

Simulation · Biology · Class 12

Pyramid of energy: the 10 per cent law

"Pyramid of energy: the 10 per cent law" is a free, interactive Class 12 Biology simulation for NEET, built on the lesson "Trophic levels and the 10 per cent law" in Ecosystem. Each bar is the energy held at one trophic level. Only a share of it passes up to the next level; the rest is lost as heat. Change the producers' energy and the share passed on. Energy falls about tenfold at each step. Because some is always lost as heat, the pyramid of energy is always upright and can never be inverted.

From the lesson Trophic levels and the 10 per cent law in Ecosystem. Change the values and watch what happens.

Pyramid of energy: the 10 per cent lawBiology · Class 12

The idea behind it

NCERT §12.4

  • An organism's trophic level is its place in the food chain, based on its source of food.
  • Producers form the first trophic level, herbivores (primary consumers) the second and carnivores (secondary consumers) the third.
  • The amount of energy decreases at each successive trophic level.
  • When any organism dies it becomes detritus, dead biomass that is an energy source for decomposers.
  • The standing crop is the mass of living material at a trophic level at a given time, measured as biomass or as number per unit area.
  • Biomass is given as fresh or dry weight; dry weight is the more accurate measure.
  • The 10 per cent law: each trophic level receives just a tenth of the energy held by the level below it.
  • This limits the number of levels in a grazing food chain: producer, herbivore, primary carnivore, secondary carnivore.

Questions

2 answers

What does the "Pyramid of energy: the 10 per cent law" simulation show?
Each bar is the energy held at one trophic level. Only a share of it passes up to the next level; the rest is lost as heat. Change the producers' energy and the share passed on.
Is this simulation free?
Yes. It is free and runs in the browser on a phone or a laptop. It belongs to the lesson "Trophic levels and the 10 per cent law" in Ecosystem (Class 12 Biology).

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