(i) Saprophytic nutrition: It is that nutrition in which an organism obtains its food from dead organic matter of dead plants, dead animals and rotten bread. Example: Fungi and many bacteria obtain food by saprophytic nutrition.
(ii) Parasitic nutrition: It is that nutrition in which an organism derives its food from the body of another living organism (called its host) without killing it.Example: Plasmodium and round worms obtain food by parasitic nutrition.
(iii) Holozoic nutrition: It is that nutrition in which an organism takes the complex organic food materials into its body by the process of ingestion; the ingested food is digested and then absorbed into the body cells of the organism.Example: Human beings obtain food by holozoic nutrition.