Organism Types in Ecosystem

Producer (autotroph): refers to an organism which makes its own food e.g. moss, fern, photosynthetic bacteria use light as an energy source in photosynthesis and some bacteria use chemosynthesis where energy is released by chemical reactions and acts as the energy source.

About 1 % of light is taken in by plants and used to produce food. This energy is then stored in chemical bonds e.g. glucose and starch.  Plants break down these molecules to release energy through respiration. This energy is used to make new cells or repair old cells. Most of a plant's energy is lost in the form of heat and only about 10% is transferred on to other organisms.

Consumer (heterotroph) is an organism that takes in food from another organism e.g. herbivores, carnivores, omnivores, decomposers and saprophytes.

• Herbivore – is an animal which eats plants only e.g. rabbit, greenfly, honeybee.
• Carnivore – is an animal which eats meat only e.g. fox, hawk, ladybird.
• Omnivore – is an animal which eats both plants and animals e.g. sparrow, crow, blackbird, thrush, badger, field mouse, hedgehog.
• Decomposer – feeds on dead organic matter e.g. earthworm, many bacteria and fungi.
• Saprophyte – bacteria and fungi that feed on dead organic matter e.g. Rhizopus
   
• Primary consumer - an animal which feeds on producers e.g. herbivores or decomposers.
• Secondary consumer - an animal that feeds on primary consumers e.g. carnivores and scavengers (who feed on animals killed by other sources)
• Tertiary consumers feed on secondary consumers (The Physics Teacher, 2018).