1. HETEROTROPHIC NUTRITION

2. HETEROTROPHIC NUTRITION
All animals including man & all non green plants depend on green plants for organic food .They are known as heterotrophs & their mode of nutrition is called heterotrophic nutrition .This involves following steps :

3. 1. INGESTION
 This is the process in which food is taken inside the body.
2.  DIGESTION
  It is the process of breaking complex molecules of organic food into simpler molecules .This takes place with the help of digestive juices which contain different Specific enzymes acting on specific food components like carbohydrates , fat, protein etc. This process is called digestion.

4. 3 . ABSORPTION 4. ASSIMILATION 5 . EGESTION
In this process digested food is absorbed & transported to each & every cell of the body.
4. ASSIMILATION
 Inside the cell absorbed food is converted into living substance i. e. protoplasm .This is called assimilation.
5 . EGESTION
The undigested food is eliminated outside the body.