class 10 cbse science, environment

1. Group members:
Hafsa Abdul Gafoor
Shaiza Safiya
Swathy Suku
Wafa Ashique
Halima Afreen
Elize Sara Abraham

2. ENVIRONMENT
Environment means the surroundings.
Land, water, air, plants, animals, solid
wastes and other things that are
surrounding us constitute our
environment. Man and environment
are closely intertwined with each other,
to maintain a balance or equilibrium in
nature.

3. EFFECT OF ADDING WASTE TO THE
ENVIRONMENT
 Human activities produce a lot of waste
materials which are thrown away into the
environment. These wastes cause pollution of
air, water and soil.
 The waste materials produced are of two main
types. They are biodegradable wastes and non
biodegradable wastes.

4. i) Biodegradable wastes :- are wastes which are :
 decomposed into harmless substances by
microorganisms.
 Eg :- vegetables, fruits, pulses, cereals, cotton,
jute, wool, wood, leather, paper, animal dung,
animal bones etc.
ii) Non biodegradable wastes :- are wastes which are
not decomposed by microorganisms.
 Eg :- polythene bags, plastics, synthetic fibres,
glass, metals, synthetic rubber, insecticides,
pesticides etc.

6. ECOSYSTEM
 An ecosystem consists of all the living organisms in
an area along with the non living components and
their interaction. There are different types of
ecosystem. There are different types:
1. Natural ecosystems :- like forests, deserts, grass
lands, mountains, ponds, lakes, rivers, oceans etc.
2. Artificial ecosystems :- like gardens, parks, crop
fields, aquarium, zoo etc.

9. COMPONENTS OF AN
ECOSYSTEM
An ecosystem consists of two main
components.
They are:
Biotic components
Abiotic components

10. BIOTIC COMPONENTS
 Biotic components are the living components like
plants, animals and microorganisms. They consist of
producers, consumers and decomposers.
 Producers :- are green plants which produce food by
photosynthesis.
 Consumers :- are herbivores which get their food
directly from plants, carnivores which get their food
indirectly from plants and omnivores which get their food
directly or indirectly from plants.
 Decomposers :- are microorganisms which
decompose dead plants and animals. They decompose
complex organic substances into simple inorganic
substances in the soil which are again used by plants.

12. ABIOTIC COMPONENTS
 Abiotic components :-
All the non-living things make the abiotic component
of an ecosystem. Air, water and soil are the abiotic
components. Air provides oxygen (for respiration),
carbon dioxide (for photosynthesis) and other gases
for various needs of the living beings. Water is
essential for all living beings because all the
metabolic activities happen in the presence of water.
Soil is the reservoir of various nutrients which are
utilized by plants. Through plants, these nutrients
reach other living beings.

13. WHAT YOU HAVE LEARNT
 All the interacting organisms in an area together with
the non-living constituents of the environment form an
ecosystem.
 Organisms in the ecosystem are classified into three
groups: producers, consumers, decomposers.
 Organisms that make their own food from inorganic
substances are known as producers.
 Organisms that consume the food produced, either
directly from producers or indirectly by feeding on other
consumers are consumers.
 Microorganisms that break down the dead remains of
organisms, that are used by other members of the
ecosystem are decomposers.

14. QUESTIONS
Why are some substances
biodegradable and some non-
biodegradable?
Give any two ways in which
biodegradable substances would affect
the environment.
Give any two ways in which non-
biodegradable substances would affect
the environment.

15. ANSWERS
 Substances which are of organic origin are
biodegradable, while those of inorganic origin are non-
biodegradable. Organic substances can be utilized by
decomposers as food, while other substances cannot be
utilized by decomposers as food. Due to this, some
substances are biodegradable while some others are
non-biodegradable.
 Biodegradable substances can affect the environment in
following ways:
By recycling the raw materials in nature.
By improving the humus content in soil.
 Non-biodegradable substances would affect the
environment in following two ways:
By increasing the burden on the environment because
they would accumulate.
By producing harmful polluting gases, if they are burnt.

16. THE END