OUR ENVIRONMENT - NOTES AND IMPORTANT QUESTIONS
Environment
-
Everything that surrounds us is Environment. It includes both living and
non living components like temperature , rainfall, wind, soil and Minerals.
Ecosystem
-
It is formed by all the interacting organisms in an area with non living constituents
like air, water , temperature of environment together.
Natural
ecosystem- These are formed in nature. for example - ponds,
deserts, mountains, oceans, Forest
Artificial
ecosystem- These are man made ecosystems. for example - Garden ,
crop field, aquarium .
Also Read : CBSE Class X Electricity Practice Questions
Also Read : CBSE Class X Electricity Practice Questions
Biotic
components - All the living components of environment are
called biotic components. Example - plants and animals
Biotic components are of three types-
1.
Producers - Living organisms which produce their own
food are called producers.example - all green plants and certain blue green
algae which can produce food by photosynthesis are called producers.
2 .
Consumers - Those organisms which depend directly
or indirectly on producers for their food are called consumers.
These are of 4 types-
(i)
Primary consumer or herbivore - Those animals which
depends on plants only for their food. Example - goat , deer
etc.
(ii)
Secondary consumers or carnivore - Those animals which
eat flesh of the animals. Example- lion,
tiger, crocodile
(iii)
Tertiary consumers or Omnivores - Those animals
which eat plants as well as animals are omnivores. Example - cat, human
(iv)
Parasites - Those organisms which live on the body
of host and take food from it . Example - lice , virus
3. Decomposers
- Those
microorganisms which decompose the dead plants and animals. Example- bacteria,
Fungi, Hawk, eagle.
They help in replenishment of natural resources and clean the environment.
They help in replenishment of natural resources and clean the environment.
Abiotic
components - The non living components of our environment
which interact with biotic components
for their growth, reproduction and other activities. Example - air,
water, soil
Food
chain - It is a Series of organisms in which one organism eats
and other organisms as a food. Example - Grass → Deer→ Lion
Trophic
level - Each level of the food chain is called trophic
level. There is transfer of energy between each trophic level. Flow of energy
in trophic levels in food chain is unidirectional. Energy goes on decreasing
from each trophic levels to next trophic level.
Food
web - It is formed by interconnecting large number of food
chains.
Ten
percent law - Green plants capture 1% of Sunlight and
convert it into food energy. Only 10% of energy is transferred to the next
trophic level. The remaining 90% of energy is consumed in life processes like
digestion, growth, reproduction by each trophic level.
Biological
magnification - The concentration of toxic substances
like pesticides, insecticides increases with each trophic level in food chain.
It is called Biological magnification. Humans occupy top position in food
chain, so maximum toxic substance are present in human bodies.
Environmental
Waste - Waste is
any substance which is discarded after primary use, or it is worthless,
defective and of no use. Examples - municipal solid waste (household trash/refuse), wastewater (such as sewage, which
contains bodily wastes (feces
and urine) and surface runoff), etc.
Biodegradable
substances - The substances that can be decomposed
by microorganisms and do not persist in environment is can be converted into
compost are called biodegradable substances. Example - plant waste and animal waste.
Non
Biodegradable - Substances the substances which cannot be
decomposed by microorganisms and persist in the environment are called Non
Biodegradable substances. This should be recycled or reused .
Waste
management -
- Biodegradable waste and non biodegradable waste should be put in separate dust bins.
- Biogas plant is excellent way of disposal of waste in rural areas.
- Sewage treatment plants are must in urban areas to detox water before releasing into river.
- Landfilling can be decomposed in a pit that changes waste into manure and sold to farmers, home makers for kitchen garden.
- Recycling of non biodegradable waste is must to clean environment.
- Newspapers can be recycled very easily and used for making envelopes, eco friendly carry bags.
Ozone
-
It is formed in upper atmosphere by action of UV light on Oxygen.
- Ozone is Deadly poison. Ozone protect us from harmful UV radiations of the Sun.
- UV radiation is highly harmful for living organisms, it can cause skin cancer in humans.
Ozone
depletion - Ozone Layer is getting thinner and
thinner day by day. It is due to the use of CFC ( chlorofluorocarbons) in
refrigeration, in fire extinguishers and air conditioners.
- UNEP (United Nations Environment Programme) has succeeded in reaching in agreement to freeze CFC production to save environment and stop its production. it is called KYOTO Protocol.
Also Read : Class 10 Probability Important Questions
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