- Heterotrophic nutrition
Heterotrophic nutrition
Animals, fungi, many prokaryotes and protoctists are unable to synthesize organic compounds to use as food. They are called
heterotroph s.Heterotrophic organisms have to acquire and take in all the organic substances they need to survive [ [http://www.int-res.com/articles/meps/22/m022p101.pdf Heterotrophic nutrition and control of bacterial density] ] .
All heterotrophs (except blood and gut parasites) have to convert solid food into soluble compounds capable of being absorbed (digestion). When the soluble products of digestion are absorbed they are distributed to various parts of the organism where complex materials (assimilation) or broken down for the release of energy (respiration).
There are four main types of heterotrophic nutrition these are:
1.
Holozoic nutrition : in which complex food is taken into a specialist digestive system and broken down into small pieces to be absorbed. This consists of 5 stages,ingestion ,digestion ,absorption ,assimilation andegestion .2. Saprobiontic/saprotrophic: in which organisms feed on dead organic remains of other organisms.
3. Parasitism: in which organisms obtain food from other living organisms (the host). With the host receiving no benefit from the parasite.
References
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