Question

Which of the following require maximum energy?
A) Secondary consumer
B) Decomposer
C) Primary consumer
D) Primary producer

Answer 1

Hint: The flow of energy in the form of food takes place from the producers followed by consumers and then decomposers. These are termed as different trophic levels in a food chain. Only ten percent of the energy is transferred to the next trophic level.

Complete answer:
The food chain represents the linear flow of energy in terms of food in an ecosystem. It shows which organisms eat whom. Each level in a food chain is known as the trophic level. The ultimate source of energy in the ecosystem is the sun. The energy of the sun is harnessed by the producers which are consumed by consumers and then decomposers.

Let us discuss each trophic level-
I) Primary producers are the autotrophs or the plants which convert the solar energy into chemical energy which can be utilised by other organisms. The maximum energy is required as well as produced in this trophic level as the other organisms depend directly or indirectly on the producers for food and energy.
II) Primary consumers- This level comprises herbivores that depend on the producers completely. They receive only ten percent of the energy produced from the producers.
III) Secondary consumers include the carnivores which feed on the primary consumers. They receive only ten percent of the energy from the primary consumers.
IV) Decomposers- They occupy the highest trophic level. The energy requirement is the lowest at this level. They feed on the dead remains of plants and animals.

Therefore the correct answer is option ‘D’.

Note: There is successive loss of energy as we move up in the trophic levels. Only ten percent of energy is passed on to the next level and the rest ninety percent is lost in the form of heat. So the pyramid of energy is always upright.