Nutrition is the process of acquiring energy and material for cell metabolism. Heterotrophic organism is organism that cannot synthesis organic substance from inorganic substances so they feed on an organic source of carbon. Heterotrophic depends directly or indirectly on the activities of autotrophs. Heterotrophs include all animals, fungi, many bacteria and single cell animal.
Forms of heterotrophic nutrition
Saprotrophic or saprobiontic
A saprobion feed on dead and decaying organic matter e.g fungi (mushroom and toad stool) which secreting enzyme unto their food and digest it before absorbing the products into their bodies.
Holozoic heterotrophs feed on solid organic matter. Their diet consists of plants material, animal materials or both (herbivorous, carnivorous and omnivorous). Heterotrophs that feed or solid organic matter can further be classified according to the relative size of the particle of food they ingest.
Microphagous feeders which feed on relatively large particles.
Microphagous feeders do feed on relatively small particles.
Liquid or fluid feeders:
Liquid feeders consume a variety of plant and animal juices or soft tissues. Some liquid feeders are free living (Bees, homing birds) other are external parasite that attack the surface of the life of their living host and suck up juice from their bodies e.g. mosquitoes and others are internal parasites which are usually bathed in nutrients and absorb their food from the host e.g. liver flukes, tapeworm.
This involves the living together in close association of two or more organism of different species. 3 common type of symbiotic nutrition are.
Mutualism is a type of nutrition in which both partners benefit e.g. microcyte, herbivorous ruminants and cellulose digesting bacteria, noodles.
Parasitism is in which one particular benefit and the other harmed e.g. Endoparasite, Ectoparasite and facultative parasite exists.
In which one partner benefit but the other receives no harm in benefit e.g. lichens