Which of the following statements are correct?
1. Organisms at each trophic level rely on the trophic levels below them for their energy needs.
2. The base of the food chain is primarily composed of carnivores that convert chemical energy into sunlight.
3. Energy transfer through trophic levels is 100% efficient, allowing for an equal number of organisms at each level.
4. Herbivores obtain their energy by consuming primary producers like plants and algae.
5. Each successive trophic level has more available energy and can support more organisms compared to the trophic level below it.
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → 1 and 4 are correct.
True. 1. Organisms at each trophic level rely on the trophic levels below them for their energy needs. Every level gets its energy by feeding on the level below; all animals depend on plants directly or indirectly.
False. 2. The base of the food chain is primarily composed of carnivores that convert chemical energy into sunlight. The base is formed by producers (green plants). They change sunlight into chemical energy in food, not the other way round.
False. 3. Energy transfer through trophic levels is 100% efficient, allowing for an equal number of organisms at each level. Only about 10 per cent of the energy passes to the next level. The rest is lost, mostly as heat.
True. 4. Herbivores obtain their energy by consuming primary producers like plants and algae. Herbivores are the primary consumers at the second trophic level; they feed on the producers.
False. 5. Each successive trophic level has more available energy and can support more organisms compared to the trophic level below it. The amount of energy decreases at each higher level, so fewer organisms can be supported there.
Statements 1 and 4 are correct.
NCERT Extract:
Energy Flow – “… Producers belong to the first trophic level, herbivores (primary consumer) to the second and carnivores (secondary consumer) to the third …. … The important point to note is that the amount of energy decreases at successive trophic levels. When any organism dies it is converted to detritus or dead biomass that serves as an energy source for decomposers. Organisms at each trophic level depend on those at the lower trophic level for their energy demands.”
Energy Flow – “… The number of trophic levels in the grazing food chain is restricted as the transfer of energy follows 10 per cent law – only 10 per cent of the energy is transferred to each trophic level from the lower trophic level.”