2. WHAT IS ENVIRONMENT ?`
 The physical and biological world where we live is called
environment
The environment includes our physical surrounding like air (or
atmosphere , water bodies , soil (land)and all the organisms such as
plants ,animal ,human beings and micro-organisms like bacteria and
fungi(called decomposers)

4. • All the waste material produced by the various activities are
poisonous to some extent and can be divided into two main
group :
1. Biodegradable waste
2. Non Biodegradable waste

5. THO•SE .WASTE MATERIALS WHICH CAN BE
BROKEN DOWN TO NON-POISONOUS
SUBSTANCES IN NATURE Is DUE COURSE OF
TIME BY THE ACTION OF MICRO-ORGANISAM
LIKE CERTAIN BACTERIA,ARE
CALLED BIODEGRSDABLE WASTE .
Some examples of biodegradable materials
are : animal bones ; leather ; vegetable
peels ; tea leaves ; wool ; paper ; wheat
;wood and etc.

6. • THOSE WASTE MATERIALS WHICH CAN
not BE BROKEN DOWN by NON-POISONOUS
SUBSTANCES IN NATURE
and DUE COURSE OF TIME BY THE
ACTION OF MICRO-ORGANISAM LIKE
CERTAIN BACTERIA,ARE CALLED non-
BIODEGRSDABLE WASTE .
Some example are : plastics ; polythene
bags ; glass objects ; iron nails ; silver foil
and etc.

8. ECOSYSTEM
• An ecosystem is a self – contained unit of
livings (plants, animal, and decomposer),and
their living environment (soil, air and water).
Some example are ; a
forest ; a desert ; a ponds ;
a lake ; a river ; and sea .

9. .
1. Abiotic components
2. biotic components

10. ABIOTIC COMPONENTS
• Abiotic components means non living components
Its include the physical environment like soil, water and air
alongwith the inorganic substances like carbon dioxide
,nitrogen and oxygen

11. BIOTIC COMPONENTS
Biotic components means living components
The biotic community of an ecosystem includes three types of
organisms :
1. Producer (or autotrophs) :_ Which synthesize their owe food . All the green plants are
producer
2. Consumer (or heterotrophs) :_
3. Decomposer (or saprotrophs) :_
Which are dependent on other for food . All the
animal are consumer
Which consume the dead animal of other organisms
certain bacteria and fungi are decomposer.

13. FOOD CHAIN
• The food (or energy) can be transferred from one
organism to other through food chain
The food chains generally consist of three
or four steps

14. FOOD WEB
• The inter –connected food chain operating in an ecosystem a net-work
of relationship between various species , is food web

15. • The various steps in a food chain at which the transfer of food
take place are called trophic levels
The various trophic levels in a food chain can be represented
diagrammatic as shown in figure

16. ,
• .

18. .

20. QUIZ
1.Food chains of ………or………stetph .ree four
2. In nature all green plants are ................... whereas animals are consumer . Producer
3. Pesticides enter the food chain at the ………………. Level .
Producer
4 ….………………. Dependent on other for food .
5. Herbivores constitute the ……………trophic level . Second

21. .
6. Which of the following constitutes a food chain ?
• .
(A) Grass, Wheat and mango
(B) Grass , goat and human
(C)Goat , cow and elephant
(D)Grass ,fish and goat

23. ROHI T KUM A R
SINGH