Page 3 - Lesson note-Ecosytem
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temperature and anaerobiosis inhibit decomposition.
Energy Flow- All living organisms are dependent for their food on producers, directly or
indirectly. There is a unidirectional flow of energy from the sun to producers and then to
consumers. Photosynthetically active radiation (PAR) is responsible for 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 food chain in which energy flow from producers to
consumers. In Grazing food chain (GFC)-
The detritus food chain begins (DFC) begins with dead organic matter. It is made up of
decomposers which are heterotrophic organisms (fungi and bacteria). These are also known
as saprotrophs (sapro: to decompose). Decomposers secrete digestive enzymes that
breakdown dead and waste materials into simple, inorganic materials, which are
subsequently absorbed by them.Natural interconnection of food chain forms the food web.
Based on source of food, organism occupies a specific place in food chain that is known as
trophic level.
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