(a) What is an ecosystem? List its two main components.

(b) We do not clean ponds or lakes, but an aquarium needs to be cleaned regularly. Explain.

(a) An ecosystem is defined as a self contained unit of living things and non living things. An ecosystem required Sunlight to maintain its working.

The two main components of an ecosystem are following:

1. Abiotic component: It includes all the non-living components such as soil, water, air temperature, rocks, etc.

2. Biotic component: It includes all living components. All flora and fauna comes under biotic components.

(b) A pond or lake is not required to be cleaned because they have their own natural system to clean them but aquarium is a man-made ecosystem and consists of a very small area or space. Moreover, the abiotic components are supplied by human and are not naturally. So. For survival of living bodies in the aquarium, it is necessary that it should be cleaned regularly.