Plants and some bacteria are autotrophs, meaning they can produce their own food using photosynthesis. During photosynthesis, autotrophs use carbon dioxide, water, and energy from sunlight to produce oxygen and carbohydrates like glucose. These carbohydrates provide energy and nutrients for the autotroph. Animals and other organisms are heterotrophs because they cannot produce their own food and rely on autotrophs or other organisms for nutrients. Heterotrophs obtain nutrients by eating autotrophs and other organisms. Humans and other animals eat food to get nutrients and energy from carbohydrates, fats, proteins, vitamins, and minerals which are used to power life processes and allow growth.

2. Why we eat food??
 To get energy.
To get nutrition.
 To carry out life processes.
To Grow stronger.
List the nutrient that we obtain from food.
Carbohydrates, Fats, Protein, Vitamins, Minerals and
water along with dietary fibres or roughage.

3. By SUSHILA DHANKHAR

4. MEANING OF NUTRITION
Nutrition is a process of taking food and its
utilisation by the body.
 Foods may be obtained from:-
 Plant Products & Animal Products
Plants can synthesize food for themselves but
animals cannot including humans.

5. MODE OF NUTRITION IN PLANTS
 AUTOTROPHIC HETEROTROPHIC
Nutrition Nutrition
Auto= self. Heteros=Others
Trophos= Nourishment.
Two types of mode of Nutrition are:-
Autotrophic and Heterotrophic.
Autotroph:- Those organism that prepare their own food
from simple substances present in our surroundings.They
are primary producers.
Heterotrophs: Those organism that depends on others for
their food or depends on producers.

6. Difference between autotroph and
heterotrophs
 Autotrophs are
organisms that prepare
their own food.
 These are known as the
producers and include
green plants, algae and a
few photosynthetic
bacteria.
 They contain chlorophyll
helps in preparing food.
 Heterotrophs depend
upon other organisms for
nutrition.
 These are the consumers
and include cows,
buffaloes, tigers, horses,
etc.
 They do not contain
chlorophyll so cannot
their own prepare food.

7. How plants prepare their food?
 Plants prepare their own food by the process of
photosynthesis.
 Leaves are the food factories of plants. Therefore, all the
raw materials must reach the leaf.
 Water and minerals present in the soil are absorbed by the
roots and transported to the leaves.
 Carbon dioxide from air is taken in through the tiny pores
present on the surface of leaves. These pores are
surrounded by ‘guard cells’. Such pores are called stomata.
 leaves have a green pigment called chlorophyll. It helps
leaves to capture the energy of the sunlight.

8. Raw Materials for photosynthesis:-
 Water and carbon dioxide (CO2).
 Presence of sunlight.
 Presence of chlorophyll.
 Solar energy is used to synthesise
(prepare) food from carbon dioxide and
water. Since the synthesis of food occurs in the
presence of sunlight, it is called
photosynthesis (Photo: light; synthesis :
to combine).

9. Summary of photosynthesis
 6 CO2 + 6H20
Carbon dioxide + Water
In the presence of sunlight and chlrophyll.
 Thus, sun is the ultimate source of energy
for all living organisms.
C6H12O6 + 6O2
Glucose + Oxygen

10. Takes place in Chlorophyll
Necessary factors :
CO2
Chlorophyll
SpongyMesophyll
Cell
AirSpace
Stoma
Site for photosynthesis in leaf

11. carbon dioxide and water
photosynthesis
carbohydrates (e.g. glucose)
release energy by respiration

12. convert into starch for storage because
glucose is not a very good storage molecule
carbon dioxide and water
photosynthesis
carbohydrates (e.g. glucose)

13. ASSIGNMENT
 Q 1. DEFINE THE TERMS:-(a) Nutrition
(b) Autotroph (c) Heterotroph (d) Photosynthesis
Q2. List out the examples of Autotrophs.
Q3. Why we need food?
Q4. Differentiate between autotroph and heterotroph.
Q5 Draw diagram of photosynthesis and write the word
equation of photosynthesis.