Food chain : a series of organisms each dependent on the next as a source of food ; the series of processes by which food is grown or produced, sold, and eventually consumed.
Food web : network of food chains or feeding relationships by which energy and nutrients are passed on from one species of living organisms to another.
Ecosystem : Self-sustaining community comprised of interdependent organisms (plants, insects, animals) and their natural environment. It provides the food chain through which energy flows, and the biological cycles that recycle essential nutrients and wastes.
Habitat : 
Sum of all environmental conditions at a particular place ; Localized surroundings to which an organism, species, or community is specially adapted and which provides for its all or nearly all needs. A habitat comprises of physical factors such as light, moisture, and temperature and of biological factors such as presence of food and predators. In contrast it ranges from a cliff top to the ocean floor, and in size from under a stone to an entire continent such as the Arctic.
Biomass : .Organic matter available on renewable basis, such as agricultural crops, aquatic plants, animal, municipal, and wood wastes.

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