ICSE Class 9 Answered

A pond is a well-demarcated area containing water persisting year after year. It is a non-flowing body of water.

The biotic components of a pond include producers, consumers and decomposers.

Producers are the green plants growing in pond, some growing along the borders, some on the surface of water and some even submerged under water. The producers include microscopic phytoplankton like Chlamydomonas and diatoms. There are also macroscopic plants like algae, Chara and Angiosperms like Hydrilla and Vallisneria.

The consumers include primary, secondary and tertiary consumers.

Primary consumers or herbivores are the zooplankton or plant-eating fishes that feed on phytoplankton present in the pond. Daphnia and Copepods are the examples of primary consumers.

Secondary consumers are the aquatic insects that feed on the zooplankton. Ranatra or water scorpion and Bellostoma are the examples of secondary consumers.

Tertiary consumers are the large fishes and water snakes that feed on small fishes.

Decomposers are the aquatic bacteria and fungi that decompose both, dead organisms that live in the pond as well as their excretory matter. They replenish the nutrients in water as well as in the soil.

The abiotic components of a pond include energy from sunlight, gases such as oxygen and carbon dioxide, temperature, water and organic salts dissolved in it.

Carbon dioxide, sunlight and water act as raw materials for the green plants to carry out photosynthesis.

Producers use the abiotic components to produce energy. This energy is then passed on to the primary, secondary and tertiary consumers due to their interaction with the abiotic components.