3. An ecosystem is a biological environment consisting
of all the living organisms or biotic component, in a
particular area, and the nonliving, or abiotic
component, with which the organisms interact, such
as air, soil, water and sunlight.

4. Abiotic components includes :
physical environment ,
inorganic substances ,
physical factors .
Biotic components
includes:
A community of organisms
which is made up of many
different inter -dependent
populations .

5. FOOD WEB
The inter-connected food chains
operating in an ecosystem which
establish a network of relationships
between various species, is called
food web.

7. F O O D C H A I N
The sequence of living organisms in a
community in which one organism consumes
another organism to transfer food energy, is
called food chain
Consider with an example [IN FOREST]
GRASS DEER TIGER

8. IN GRASSLAND
PLANTS WORMS BIRDS CAT
IN A POND
ALGAE PROTOZOA SMALL BIG
FISH
FISH

9. TROPIC
LEVELS
The various steps in
a food chain at which
the transfer of food
takes place are called
tropic levels.

11. RAYMOND LINDEMAN : The
scientist who gave ten percent
law for transfer in food chain .
This law was given by him in
1942 .
According to his law ,only 10
percent of the energy entering a
particular trophic level of orgnisms
is available for transfer to the
next higher trophic level

12. What will happen if we kill all the
organisms in one trophic level ?
Organism in the next trophic level
will decrease due to none
availability of food
Organism in the lower trophic
levels will increase because no
one will be there to feed upon them
This will result in the imbalance in
the ecosystem

13. The decomposers help in decomposing the dead
bodies of plants and animals and hence act as
cleansing agents of environment ..
They help in recycling the material in the
ecosystem so that the process of life may go on
and on like an unending chain

14. BIOLOGICAL MAGNIFICATION
Certain harmful substances, usually ones not found in nature but introduced
by man, may get into plants and animals. These poisonous substances
may not be broken down in the body . Instead, they accumulate in the
tissues, and as the living organism eats more, the concentration of these
substances increases and they pass from one trophic level to the next.

17. Two main reasons are :-
* Ozone layer
* Garbage disposal

18. OZONE (O3)
MADE BY THREE ATOM OF OXYGEN
OXYGEN IS THE MOST IMPORTANT
OZONE IS DEADLY HARFULL
IT COVERS OUR EARTH
PROTECTS FROM UV RAYS

19. Ozone at the higher level of the atmosphere is a
product of UV-rays acting on oxygen molecule.
UV-rays split the oxygen(O2)in to free oxygen
atom.
02 uv-rays O+O
O+O2 O3(Ozone)

20. Depletion of
ozone
Due to CFCs
(refrigerants)
In year 1987
CFCs are
stopped in
use

22. Acid rain damages trees and pollutes rivers and lakes.

23. carbon dioxide traps heat in
the atmosphere and causes
the temperature of the earth
to rise.
This leads to disruption of
the weather patterns eg
drought, floods
Some weeds may thrive on
the extra carbon dioxide
while other plants are killed

26. The material which can be broken down by the action of
micro-organisms are called biodegradable substances .
This action is caused the biological agents such as
bacteria ..
The materials which cannot be broken down
into harmless substances in natue by these
agents are called non biodegradable
substances ..

27. What
about
plastics
???
Plastic usually is non-biodegradable, because there are very few
natural processes that could break the plastic down into smaller
elements, whereas something like wood, will rot and decay and be
recycled back into the soil.

29. • The less use of natural resources by cutting down
on those practices which lead to their wastage . .
• Using the same things again …
• We should collect the used and discarded items of
paper ,plastics ,glass ,and send them to the
respective indutries for making fresh paper ,plastic
etc..

30. ways to reduce pollution ………
Avoid dumping garbage on the street. Dispose them in a
garbage dump; you can also make a compost pit to convert
garbage into manure .
Avoid using plastic materials such as plates and carry bags which cannot
be used again
•Request your family members to use automobiles only when necessary;
walking or cycling can be a pleasure when the distance is short;

31. OUR
EARTH
IS NOT
A
DUST BIN
We can protect our environment in many ways. Let us act now and persuade others to
join us.
This will ensure safety for our future generations.

32. Thank you .
Made by
DIVYA SHRI
SNEHA
URVASHI