An ecosystem is a self-contained unit of living things (plants, animals and decomposers), and their non-living environment (soil, air and water). For example; a forest, a pond, a lake, a green land etc.In an ecosystem, energy and matter are continuously exchanged between living and non- living components. An ecosystem can be both natural or man-made. Some examples of natural ecosystems are grass land, forest, sea, river, desert,- mountain, pond, lake etc.1. The constituents which do not form eco-system area. Biotic constituentsb. Plastic bagsc. Abiotic constituentsd. All of these2. Which of the following is terrestrial ecosystem?a. A natural forestb. A lakec. A pondd. An aquarium3. ________ is not an abiotic factor.a. Humidityb. Animalsc. Temperatured. Altitude4. An ecosystem includes ______.a. All living organismsb. non living objectsc. both living and non living componentsd. sometimes living sometimes non living5. Universal producer in an ecosystem is :a. Plantb. Animalc. Fungid. Algae