3 types of heterotrophic nutrition.
Explain each one of them.
Answers
1. Saprophytic or Saprotrophic Nutrition :
It is a mode of heterotrophic nutrition in which food is obtained from organic remains like dead organisms, excreta, fallen leaves, broken twigs, food articles, etc. Organisms performing saprophytic nutrition are called saprophytes.
2. Parasitic Nutrition :
It is a mode of hetrotrophic nutrition in which a living organisms flourishes by obtaining food from another living organism. The lving organisms which obtains food and shelter from another organism is called parasite. The organism which provides food and shelter to a parasite is known as host. An external plant parasite is Cuscuta (Amarbel). It is a non-green plant that sends haustroria or sucking roots into host plant for obtaining food and water.
3. Holozoic Nutrition :
It is a mode of heterotrophic nutrition which involves intake of solid pieces of food. Since solid food is taken in, holozoic nutrition is also called ingestive nutrition. The food may consist of another animal, plant or its parts. Depending upon the source of food, holozoic organisms are of three types – Herbivores, carnivores, omnivores.
Heterotrophic Nutrition:- The type of nutrition in which organisms derive their food (nutrients) from other living organisms. In heterotrophic nutrition, the energy is derived from the intake and digestion of the organic substances, normally of plant or animal tissue.
Heterotrophic mode of nutrition are of different types:
1. Saprotrophic Nutrition:- It refers to themode of nutrition in which organisms obtain nutrients from the dead and decaying organic matter, e.g., fungi, yeast and bacteria are called saprophytes.
2. Parasitic Nutrition:- It refers to the mode of obtaining food synthesised by others. The organism which obtains food is called the 'parasite' and the organism from which food is absorbed is called the 'host’. This nutrition is observed in fungi, bacteria, a few plants like Cuscuta and some animals like Plasmodium and roundworm.
3. Holozoic Nutrition:- It refers to the mode of nutrition in which the complex organic matter in the form of solid food is ingested, digested and then absorbed into the cells and utilised, e.g., Amoeba, frog, human beings.