Our environment, Grade 10, Biology. This power point presentation explains the topic 'Our Environment' of grade 10 cbse.

1. OUR ENVIRONMENT
Huda Fathima 10 A

2. Ecosystem
• An ecosystem is all the different organisms in the world living
together in a particular environment or habitat. Our own bodies are
homes to tiny living organisms. All the ecosystems combined together
make up the biosphere.
• An ecosystem is an environment in which plants (flora) and animals
(fauna) live. Ecosystems survive through the interactions between
plants and animals and an example of this is what are referred to as
food chains and food webs. Without these interactions, ecosystems
risk breaking down and could be destroyed .
•Ecosystem is the collection of organisms in an area along with the
important environmental factors. Eg: ocean ecosystem

3. Types of ecosystem
•Natural ecosystems :- like forests, deserts, grass lands, mountains,
ponds, lakes, rivers, oceans etc.
•Artificial ecosystems :- like gardens, parks, crop fields, aquarium,
zoo etc.

4. Components of ecosystem

5. Components of ecosystem
•Abiotic factors
Nonliving chemical and physical components of the environment
like the soil, air, water, temperature, etc.
•Biotic factors
Living organisms of the environment like the plants, animals,
microbes, and fungi.

6. Biotic factors
Producers
Consumers
1)Herbivores
2)Carnivores
3)Omnivores
Reducers/ Decomposers

7. Producers
Organisms that produce their own food from simple inorganic
substances such as water and carbon dioxide are called producers.
Examples are green plants and blue-green algae.

8. Consumers
The organisms which consume the food produced either directly or
indirectly are called consumers. Consumers can be classified into
primary, secondary and tertiary consumers based on their mode of
nutrition.
All herbivores and some parasites are primary consumers. Example-
rabbit, which eats grass.
Many small carnivores and some parasites are secondary consumers.
Example- snake, which eats rabbits.
Larger carnivores and omnivores are tertiary consumers. Example- owl,
which eats snakes.

9. Decomposers
Organisms that use the organic matter of dead plants and
animals are called decomposers. They release digestive
enzymes to break down organic matter and then absorb the
products of digestion. Decomposers include fungi and
bacteria. Decomposers do not fit readily into one trophic
level.

10. Food Chain
A food chain is a linear sequence of links in a food web starting from a
species that are called producers in the web and ends at a species that is
called decomposers species in the web. A food chain also shows how the
organisms are related with each other by the food they eat. A food chain
differs from a food web, because the complex polyphagous network of
feeding relations are aggregated into trophic species and the chain only
follows linear monophagous pathways. A common metric used to quantify
food web trophic structure is food chain length. In its simplest form, the
length of a chain is the number of links between a trophic consumer and
the base of the web and the mean chain length of an entire web is the
arithmetic average of the lengths of all chains in a food web

11. Difference Between Food Chain
And Food Web
Food Chain
• A food chain only follows
just one path as animals
find food.
Food Web
• A food web consists of
many food chains.

12. Trophic levels
Each step in a food chain where transfer of food energy takes
place is called trophic level.
The first trophic level consists of producers.
The second trophic level consists of primary consumers.
The third trophic level consists of secondary consumers.
The fourth trophic level consists of tertiary consumers.
Since the transfer of food energy decreases at every trophic
level, the number of trophic levels are limited and do not
exceed four or five.

14. Energy flow in trophic levels
Green plants (producers) absorb about 1% of solar energy
falling on the leaves and stores it as food energy during
photosynthesis.
During the transfer of food energy from one trophic level to
the next, 90% of the energy is lost to the environment and
only 10% is transferred to the next trophic level. So there is
a decrease in the amount of food energy transferred at
every trophic level by 10%. This is known as the 10% law.

16. Depletion of ozone layer in the
atmosphere
Ozone molecule contains three oxygen atoms (O3). At higher levels in the
atmosphere the UV radiation splits some oxygen molecules (O2) into free
oxygen atoms which combines with oxygen molecules (O2) to form
ozone. It is highly poisonous.
UV radiation
O2 O + O
O2 + O O3
The ozone layer present in the higher layer of the atmosphere protects
the earth from the harmful UV radiation from the sun. UV radiation
causes skin cancer in humans.
The ozone layer is being damaged by the use of chemicals like chloro
fluoro carbons (CFCs) used in refrigerators and fire extinguishers. So the
use of CFCs is now being reduced to protect the ozone layer.

18. Managing the garbage we
produce
The household waste is called garbage. Some of the garbage is
biodegradable and some are non biodegradable. Garbage causes
pollution of air, water and soil. So it should be disposed properly.
Some of the methods of garbage disposal are :-
i) Land fills
ii) Recycling
iii) Production of biogas and manure
iv) Preparation of compost
v) Incineration
vi) Sewage treatment

19. Land fills Recycling
Production of biogas and manure Preparation of compost
Incinerator

20. Sewage treatment