Question

Describe different trophic levels in an ecosystem.

Answer 1

Trophic levels

1. Trophic levels are the steps in a food chain at which transfer of food energy takes place from one organism to another.
2. All living organisms form one or the other trophic level in a food chain. In any food chain:

Producers form the first trophic level.

1. Autotrophs in an ecosystem are called producers because they produce food for all other members of the ecosystem.
2. They are green plants, blue green algae (Cyanobacteria), some bacteria and minute free-floating phytoplankton
3. . With the help of chlorophyll, carbon dioxide, water and utilizing sun's energy, they synthesize organic food.
4. During the process of photosynthesis, they release oxygen in the atmosphere.
5. Thus, nutrients and energy enter the living world through producers.

Herbivores form the second trophic level.

1. They are animals which feed on plants.
2. Herbivores are also called primary consumers or first order consumers.
3. Common examples are Rabbits, Deer, Mice, Goats, Sheep, Cattle, Horses, etc.

Carnivores form the third trophic level.

1. They are animals that prey upon herbivores (primary consumers) and eat their flesh.
2. Carnivores that eat herbivores are called primary carnivores or secondary consumers.
3. Foxes, Snakes, Frogs and small fishes are primary carnivores.

Top carnivores form the fourth trophic level.

1. They directly prey upon secondary consumers, and generally do not have predators that feed on them.
2. Example: Lion, tiger.