1. In ecology not all the pyramids are always upright.
2. Pyramid of number may be upright, inverted or partly upright.
3. Pyramid of biomass may be upright or inverted.
4. But the pyramid of energy is always upright.
5. This is because energy will decrease when we move from producers to the high level consumers.
6. Only 10% of the energy from one tropic level transfers to the other through food chain.
7. So the energy at base is more, gradually decreases, and very less at the top.
8. As a result the energy pyramid is always upright.
