Saturday, July 8, 2017

Digestion and Nutrition

The process of conversion of complex food substances to simple absorbable forms is called digestion and is
carried out by our digestive system by mechanical and biochemical methods.

Life needs energy and matter for growth, development, maintenance and various activities. Procurement of these
substances (food) is called nutrition.


  • Autotrophic : Use of solar energy to synthesize organic compound (photosynthesis) e. g., all green plants (chlorophyll).
  • Heterotrophic : Deriving food from available products of plants e. g., all animals, fungi, bacteria etc.


MODES OF HETEROTROPHIC NUTRITION

Holozoic : Consuming whole food by the animals.

Saprozoic : Absorbing decaying organic materials by the animals.

Parasitic Obtaining food at the cost of other living organisms (host) and causing harm to it e. g., Taenia,Plasmodium, Ascaris, Entamoeba, bacteria, viruses.

Mixotrophic Euglena representns this type of nutrition. In presence of light it performs photosynthesis, otherwise, shows
holozoic mode of nutrition.
Different Types Of feeding habits

No comments:

Post a Comment