Question

Flow of energy in an ecosystem is always:
A. Unidirectional
B. Bidirectional
C. Multi-directional
D. No specific direction.

Answer 1

Hint: In most natural ecosystems, there is a loss of energy by 10% when it goes from one trophic level to another trophic level in the food chain. There is only one source of energy on Earth that is Sun, energy is trapped by producers and then passed on to other organisms.

Complete answer:
When we talk about life, the source of energy is the most important factor and requirement of survival of life. On Earth, we have only one energy source that is Sun and we all get energy directly or indirectly from the Sun.
Flow of energy and cycling of different nutrients is the most important aspect and characteristic of all ecosystems. This flow of nutrients and flow of energy is described by different food chains present in the ecosystems. A food chain is a way of representation of flow of nutrients and energy in different organisms
At basic level or first level, we have producers in food chains that are organisms that observe energy from the ultimate source of energy that is the Sun. So, examples are green plants, photosynthetic bacteria, etc. Thus, producers take sunlight and process it and make food for themselves as well as all other organisms present on the Earth.
Then at secondary level organisms like goat, buffalo, etc. that are herbivores, that eat plants or depend on plants for their survival and food.
After this tertiary level comes in which organisms like tiger, eagle, etc. come which are dependent on secondary organisms or herbivores for their food and survival.
Thus, we can say that all are dependent on others for their survival and a stable food chain is very important for life to exist for a longer time and we can also conclude that energy flow is unidirectional. And our answer will be option ‘A’.

Note:
Flow of energy is unidirectional from lower level to higher levels. It will never come back to lower levels and always energy reduces when it goes to one level higher from lower levels.