11. Give an account of energy flow in an ecosystem
Energy Flow in an ecosystem
All living organisms are dependent on their food producers, directly or indirectly. There is a unidirectional flow of energy from the sun to producers(the plants) and then to consumers. Photosynthetically active radiation (PAR) is responsible for the synthesis of food by plants. Animals obtain their food from plants, so they are called consumers. The process of eating and being eaten is called a food chain in which energy flows from producers to consumers. For example, in the Grazing food chain, the grass is eaten by goats which are further eaten by man. Similarly, in the detritus food chain, the sequence begins with dead organic matter. It is made up of decomposers which are heterotrophic organisms (fungi and bacteria). These are also known as saprotrophs. Decomposers secrete digestive enzymes that break down dead and waste materials into simple, inorganic materials, which are subsequently absorbed by them. The natural interconnection of the food chain forms the food web. Thus, in an ecosystem, energy flow occurs through food chains and food webs.