This document discusses the different modes of nutrition for organisms. There are two main types of nutrition: autotrophic (self-nutrition) and heterotrophic. Autotrophic organisms like plants and some bacteria can synthesize their own food through photosynthesis using carbon dioxide, water, sunlight and chlorophyll. Heterotrophic organisms like animals and some fungi and bacteria obtain nutrients by consuming other organisms. Heterotrophic nutrition can occur through saprophitism (consuming non-living organic matter), parasitism (living off a host organism in a harmful way) or holozoic nutrition (consuming parts or whole organisms and digesting them).

1. Modes of Nutrition.
Subject-Science
Std-X
Prepared by-Eva Bhinde

2. Nutrients
Substances which provide
the two basic requirements
of organisms, namely
organic raw material and
energy.

3. Nutrition
 Process of intake of nutrients from which
organisms derive energy to work.
 Diet/Food:- Substance which supply nutrients
to the body.
Carbohydrates Proteins Fats Vitamins Water
Minerals

4. Modes of Nutrition
means
Methods of obtaining food by organisms
Two
Methods
Holotrophic /Autotrophic Heterotrophic

5. Autotrophic Nutrition
 Word ‘auto’ means self and ‘trophe’ means
nutrition. So, Autotrophic means ‘self nutrition’.
 In this type of nutrition, organisms synthesis
their own food, like carbohydrate, from water &
carbon dioxide with help of chlorophyll in
presence of sunlight.
 This process is known as Photosynthesis.

6. Examples
Euglena Volvox Green Plants
&
Bacteria
A green single-celled
freshwater organism
A green single-celled
aquatic organism

7.  Carbohydrates are used for providing energy.
 The carbohydrates which are not used, are
stored in the form of starch.
 Energy is derived from the food which is stored
in our body in the form of Glycogen.
Substance which stores carbohydrates
&
important in controlling sugar levels in bloo

8. Steps of Photosynthesis
1) Absorption of light energy by chlorophyll
2) Conversion of light energy into chemical energy
3) Reduction of carbon dioxide into carbohydrates
Substances important
for
photosynthesis
1) Sunlight
2) Chlorophyll
3) CO2

9. Heterotrophic Nutrition
 Organisms cannot synthesis their own
food.
 Energy is derived by digestion of organic
substances obtained from plants and
animals.
 After intake, food is digested into simple
forms and then organisms utilize it.
 Examples: All Animals, Some Bacteria
and Fungi

10. Types of Heterotrophic
Nutrition
Saprophitic
•Depends on non-
living substances
•Dead & decaying
organic material are
absorbed through
body wall of the
organism
•Ex:- Bacteria, Fungi
Parasitic
•Depends on another
living organisms (Host)
•Has close association
with the host and obtain
food from it.
•Host is not benefited
but harmed.
•Ex:- Bacteria, Fungi,
plants like cuscuta &
animal like tapeworm.
Holozoic
•Parts of plants or
animals or whole
organism is taken as
food.
•Digested with the
help of digestive
enzymes into simple
substance, then
absorbed by body
cells.

11. Thank You