CHAPTER:-15
OUR ENVIRONMENT
BIODEGRADABLE AND NON-BIODEGRADABLE SUBSTANCES: - Biodegradable substances are those
substances which can be composed by micro-organisms in nature. It includes all biodegradable
products such as paper, clothes, and vegetables, wood, etc., whereas some substances like
metals or synthetic substances like plastics, etc. Cannot be decomposed by micro-organisms
and are said to be non-biodegradable substances.
BIOLOGY
EFFECTS OF BIODEGRADABLE SUBSTANCES ON ENVIRONMENT :-
TAKSH
1. Biodegradable substances help in recycling of matter in nature. Gobar Gas Plant is the best
example of recycling in which dung and faeces are utilised to produce gas for cooking and
the remains form important manure.
BIOLOGY 2. They provide food for micro-organisms and maintain ecological balance. BIOLOGY
BIOLOGY
EFFECTS OF NON-BIODEGRADABLE SUBSTANCES ON ENVIRONMENT :-
TAKSH
1. The non-biodegradable substances pollute the environment.
2. Solid waste leads to germination of methane which is causing global warming.
TAKSH
TAKSH
TROPIC LEVELS: - The various steps in a food chain where a transfer of energy and matter takes
TECHNOLOGY place are tropic levels.
BIOLOGY
FOOD CHAIN :- It is a sequental transfer of energy and matter from one tropic level to another.
TAKSH
A simple form of food chain can be represented as :-
PRODUCER
PRIMARY CONSUMER
BIOLOGY
BIOLOGY SECONDARY CONSUMER
TERTIARY CONSUMER
BIOLOGY
QUATERNARY CONSUMER
TAKSH
TAKSH TAKSH
Y
TYPES OF FOOD CHAIN :- Following are the types of food chain :- VJ
TUTORIAL
1. TERRESTRIAL FOOD CHAIN :- VEGETATION GRASS SHREW HAWK
BIOLOGY HOPPER
TAKSH
2. AQUATIC FOOD CHAIN :- PHYTOPLANKTONS ZOOPLANKTONS FISH CROCODILE
SAT TECHNOLOGIES
SAT TECHNOLOGIES
DECOMPOSERS: - Decomposers are the organisms that break down the dead and decaying
form and add it to
complex matter into simplerSAT TECHNOLOGIES the soil. In this way, they help the farmers by
increasing the fertility of the soil. Further, they also create space on earth by clearing dead
bodies.
COPYRIGHT PROTECTED WITH TAKSH
CHAPTER:-15
OUR ENVIRONMENT
OZONE LAYER: - Ozone is a form of oxygen. A molecule of ozone contains three atoms of
oxygen ( ). In the stratosphere, ozone layer contains high concentration of some 18-50
kilometres above. Here, it is being dissociated and generated by the absorption of harmful,
short wave length UV radiations. While absorbing harmful ultra-violet radiations, this layer
protects all forms of life on earth.
Certain harmful chemicals such as chlorofluorocarbons (CFC’s), methane , oxides of
BIOLOGY
nitrogen , etc., produced by human activities, are thinning the ozone blanket. As a result,
more UV radiations penetrate the ozone blanket to strike the earth and producing skin cancer,
TAKSH
damage to eyes including increased incidence of contract and damage to immune system of
human beings and other animal
WASTE DISPOSAL: - Waste disposal literally means ‘getting rid of waste’. We can help in
BIOLOGY reducing the problem of waste disposal by changing our life style and attitude. If weBIOLOGY
minimise
the use of disposable articles start using only those types of articles which can be easily
BIOLOGY
recycled, we can reduce the generation of waste. We can also bury kitchen waste, fallen
leaves, etc. of kitchen garden into a pit and then using the manure form due to the
TAKSH
decomposition. Some prominent methods of waste disposal are :-
1. Landfills,
2. Recycling of waste,
TAKSH 3. Preparation of compost,
4. Protection of biogas and manure, TAKSH
5. Incineration.
TECHNOLOGY
IMPORTANCE OF ORGANISMS IN A PARTICULAR TROPIC LEVEL: - If we kill all the organisms in one
BIOLOGY
tropic level, the transfer of food energy to the next level will stop. Also, there will occur over-
population of individuals belonging to the previous tropic levels. It will bring imbalance in the
ecosystem. Suppose, all herbivoresTAKSH ecosystem are killed. There will be no food available
in an
for the carnivores of that particular area. Consequently, they will also die or will shift to the
other area. Also, population of producers will go on increasing in the absence of herbivores
bringing imbalance in the ecosystem.
BIOLOGICAL MAGNIFICATION: - The phenomenon that involves progressive increase in
concentration of harmful non-biodegradable chemicals at different tropic levels in a food chain
BIOLOGY
BIOLOGY is termed as ‘biological magnification’.
BIOLOGY
EFFECT OF BIODEGRADABLE SUBSTANCES: - If all the waste we generate is biodegradable, it will
have impact on the environment because the micro-organisms are not able to break down
these substances (biodegradable) into simpler substances at the right time and hence, they
TAKSH
will act as pollutants. It, therefore, will result in harmful effect on the environment.
DIFFERENCE BETWEEN PRODUCERS AND CONSUMERS :-
TAKSH PRODUCERS CONSUMERS TAKSH
Producers are capable of synthesizing their Consumers depend on producers and are not
Y own food by the process of photosynthesis. capable of synthesizing their own food.
VJ
These possess photosynthetic pigments called Photosynthetic pigments are absent in them.
chlorophyll. TUTORIAL
BIOLOGY
These trap solar energy and convert it into They are incapable of trapping solar energy.
chemical energy of organic compounds.
They obtain organic materials from outside by They obtain organic nutrients from outside as
TAKSH
photosynthesis. food.
They constitute the first tropic level. They belong to second and higher tropic level.
SAT TECHNOLOGIES
SAT TECHNOLOGIES
SAT TECHNOLOGIES
COPYRIGHT PROTECTED WITH TAKSH