Our Environment, Std-10
*Environment
:-> This word has been derived from the French word I.e "enviror"meaning to encircle or surrounding.
:-> The physical and biological world where we live is called our environment.
:-> It includes - 1. Physical Surrounding ( like Air, Water bodies, and Soil.
2. Living Organisms ( like plants, Animals, Humans and microorganisms - bacteria, fungi etc ).
* Ecosystem
:- A biological community of interacting organisms and their physical environment is called an ecosystem.
:- An ecosystem can be both Natural and Man - made.
:- Natural ecosystem - like grassland, a forest, a desert, a mountain, a pond, a lake, a sea, a river etc.
:- Man - made, like garden, crop field, park, aquarium etc.
:-> An ecosystem needs only the input of sunlight for its functioning.
:-> It is made up of two main components I.e Abiotic and Biotic components.
1. Abiotic Components
:- It includes non living things and physical environment like soil, air, water along with Inorganic substances like CO2, N2, and O2 etc.
2. Biotic Components
:- It includes plants, animals & also three types of Organisms like-
1. Producer or Autotrophs
2. Consumer or Heterotrophs
3. Decomposer or Saprotrophs
1. Producers
:- Those organisms which produce food are called producers.
:- They are photosynthetic.
E.g. Green plants.
2. Consumers
:- Those organisms which consume food prepared by producers are called consumers.
:- They depend on producers for food directly or indirectly.
E.g. Animals
:- They are differentiated into three categories like - Herbivores, Carnivores and Omnivores.
3. Decomposers
:- The microorganisms which break down the complex organic compounds present in dead organisms into simpler substances are called decomposers.
E.g. Bacteria & Fungi
Note:- The bacteria which act as decomposer are called putrefying bacteria.
* Importance of Decomposers
1. They help in decomposing the dead bodies of plants & animals and hence act as cleansing agents of environment.
2. They help in putting back the nutrient elements into the soil, air, and water for reusing by the producers.
3. They maintain the fertility of soil.
4. They also help in recycling of materials in the ecosystem.
So that the process of life may go on like an unending chain.
*Food Chain
:-> A sequential process in which one organism consumes another organism to transfer food energy is called food chain.
:-> It represents unidirectional transfer of energy.
E.g. 1. A grassland food chain (3- step food chain ).
i. Grass -----------> Deer ---------> Lion
( producer) ( herbivore) ( carnivore )
*5 - step food chain.
ii. Grass---->Insect--->Frog--->Snake---> Eagle
i. Phytoplanktons
:- The microscopic aquatic plants which are found freely floating on the surface of water are called phytoplanktons.
E.g. Algae.
ii. Zooplanktons
:- The microscopic animals which are found freely floating on the surface of water are called Zooplanktons.
E.g. Protozoa
2. A food chain in an aquatic ecosystem.
i. Phytoplankton----> Zooplankton----> Small fish ---> Big fishes.
ii. Algae----> Protozoan----> Fish----> Squid---> Seal
Food Web
:- The network of a large number of food chain existing in an ecosystem is called a food web.
:-> It has many inter crosses and linkages among the various species present in it.
:-> The various food chains in an ecosystem do not operate in isolation.
Fig 👉
:-> This food web has seven interconnected food chains.
1. Plant------> Rabbit------> Eagle
2. Plant-----> Rat-------> Eagle
3. Plant----> Rat----> Snake----> Eagle
4. Plant---> Seed eating bird---> Eagle
5. Plant---> Grasshopper---> Eagle
6. Plant---> Grasshopper---> Frog--->
Snake---> Eagle
7. Plant---> Grasshopper---> Bigger insect--
-->Frog---> Snake---> Eagle.
*Trophic Level
:- The various links or steps in a food chain at which the transfer of food or energy takes place is called trophic level.
:-> The producers( plants) represent the first trophic level.
:-> Herbivores represent second trophic level.
:-> Carnivores represent the third trophic level.
:-> Large or top carnivore represents the fourth trophic level.
Fig:-👇
*Significances of food chain
:-> Food chains transfer energy between various living components of an ecosystem.
:-> It gives dynamicity to an ecosystem or
biosphere.
:-> The movement of toxic substances like pesticides, weedicides and etc. through food chains can prove very harmful.
Note:- Green plants capture about 1% of the solar energy.
*Characteristics of Energy Transfer.
1. Energy is supplied by the sun and it is not created in the biosphere.
2. There is a continuous transfer of energy from one trophic level to the next in a food chain.
3. The flow of energy in trophic level is unidirectional.
4. At each trophic level some of the energy is utilized by the organisms for their growth, reproduction & development whereas some amount of energy is lost due to respiration and other metabolic activities.
:-> And remains energy get transfer to the next trophic level.
*The Ten Percent law
:-> Proposed by Raymond Lindeman in
1942.
:- According to this law - Only 10% of total energy enters a particular trophic level of a consumer & out of this only 10% is available for transfer to the next trophic level.
Fig:- 👇
*Biomagnification
:- The increase in concentration of harmful chemicals substances like pesticides in the body of living organisms at each trophic level of a food chain is called biomagnification.
:- The most common used pesticide DDT
( Dichloro Diphenyl Trichloroethane) is accumulating in our bodies through the food chains.
E.g - Water ----->Zooplanktons --->Small fishes
DDT( 0.02 ppm) ( 5 ppm) 240 ppm
-->Big fishes --->Fish eating bird / Humans
240 ppm 1600 ppm
( Note - ppm stands for Parts Per Million ).
1. Biodegradable Wastes
:- Those materials which can be broken down to non - poisonous substances in nature in due course of time by the action of microorganisms are called biodegradable wastes.
:- They do not pollute the environment.
:- E.g - Dead plants and animals, Cattle dung, urine, paper wood, seeds etc.
2. Non - Biodegradable Wastes
:- The waste materials which can not be broken down into non - poisonous or harmless substances in nature are called non - biodegradable wastes.
:- They are major pollutants of the environment.
:- E.g - DDT, Polythene bags, Plastic bags, ball point pen refill, radioactive wastes, glass objects etc.
➤ ENVIRONMENTAL PROBLEMS
1. Greenhouse Effect
:- An ecosystem can be both Natural and Man - made.
:- Natural ecosystem - like grassland, a forest, a desert, a mountain, a pond, a lake, a sea, a river etc.
:- Man - made, like garden, crop field, park, aquarium etc.
:-> An ecosystem needs only the input of sunlight for its functioning.
:-> It is made up of two main components I.e Abiotic and Biotic components.
1. Abiotic Components
:- It includes non living things and physical environment like soil, air, water along with Inorganic substances like CO2, N2, and O2 etc.
2. Biotic Components
:- It includes plants, animals & also three types of Organisms like-
1. Producer or Autotrophs
2. Consumer or Heterotrophs
3. Decomposer or Saprotrophs
1. Producers
:- Those organisms which produce food are called producers.
:- They are photosynthetic.
E.g. Green plants.
2. Consumers
:- Those organisms which consume food prepared by producers are called consumers.
:- They depend on producers for food directly or indirectly.
E.g. Animals
:- They are differentiated into three categories like - Herbivores, Carnivores and Omnivores.
3. Decomposers
:- The microorganisms which break down the complex organic compounds present in dead organisms into simpler substances are called decomposers.
E.g. Bacteria & Fungi
Note:- The bacteria which act as decomposer are called putrefying bacteria.
* Importance of Decomposers
1. They help in decomposing the dead bodies of plants & animals and hence act as cleansing agents of environment.
2. They help in putting back the nutrient elements into the soil, air, and water for reusing by the producers.
3. They maintain the fertility of soil.
4. They also help in recycling of materials in the ecosystem.
So that the process of life may go on like an unending chain.
*Food Chain
:-> A sequential process in which one organism consumes another organism to transfer food energy is called food chain.
:-> It represents unidirectional transfer of energy.
E.g. 1. A grassland food chain (3- step food chain ).
i. Grass -----------> Deer ---------> Lion
( producer) ( herbivore) ( carnivore )
*5 - step food chain.
ii. Grass---->Insect--->Frog--->Snake---> Eagle
i. Phytoplanktons
:- The microscopic aquatic plants which are found freely floating on the surface of water are called phytoplanktons.
E.g. Algae.
ii. Zooplanktons
:- The microscopic animals which are found freely floating on the surface of water are called Zooplanktons.
E.g. Protozoa
2. A food chain in an aquatic ecosystem.
i. Phytoplankton----> Zooplankton----> Small fish ---> Big fishes.
ii. Algae----> Protozoan----> Fish----> Squid---> Seal
Food Web
:- The network of a large number of food chain existing in an ecosystem is called a food web.
:-> It has many inter crosses and linkages among the various species present in it.
:-> The various food chains in an ecosystem do not operate in isolation.
Fig 👉
:-> This food web has seven interconnected food chains.
1. Plant------> Rabbit------> Eagle
2. Plant-----> Rat-------> Eagle
3. Plant----> Rat----> Snake----> Eagle
4. Plant---> Seed eating bird---> Eagle
5. Plant---> Grasshopper---> Eagle
6. Plant---> Grasshopper---> Frog--->
Snake---> Eagle
7. Plant---> Grasshopper---> Bigger insect--
-->Frog---> Snake---> Eagle.
*Trophic Level
:- The various links or steps in a food chain at which the transfer of food or energy takes place is called trophic level.
:-> The producers( plants) represent the first trophic level.
:-> Herbivores represent second trophic level.
:-> Carnivores represent the third trophic level.
:-> Large or top carnivore represents the fourth trophic level.
Fig:-👇
:-> Food chains transfer energy between various living components of an ecosystem.
:-> It gives dynamicity to an ecosystem or
biosphere.
:-> The movement of toxic substances like pesticides, weedicides and etc. through food chains can prove very harmful.
Note:- Green plants capture about 1% of the solar energy.
*Characteristics of Energy Transfer.
1. Energy is supplied by the sun and it is not created in the biosphere.
2. There is a continuous transfer of energy from one trophic level to the next in a food chain.
3. The flow of energy in trophic level is unidirectional.
4. At each trophic level some of the energy is utilized by the organisms for their growth, reproduction & development whereas some amount of energy is lost due to respiration and other metabolic activities.
:-> And remains energy get transfer to the next trophic level.
*The Ten Percent law
:-> Proposed by Raymond Lindeman in
1942.
:- According to this law - Only 10% of total energy enters a particular trophic level of a consumer & out of this only 10% is available for transfer to the next trophic level.
Fig:- 👇
:- The increase in concentration of harmful chemicals substances like pesticides in the body of living organisms at each trophic level of a food chain is called biomagnification.
:- The most common used pesticide DDT
( Dichloro Diphenyl Trichloroethane) is accumulating in our bodies through the food chains.
E.g - Water ----->Zooplanktons --->Small fishes
DDT( 0.02 ppm) ( 5 ppm) 240 ppm
-->Big fishes --->Fish eating bird / Humans
240 ppm 1600 ppm
( Note - ppm stands for Parts Per Million ).
1. Biodegradable Wastes
:- Those materials which can be broken down to non - poisonous substances in nature in due course of time by the action of microorganisms are called biodegradable wastes.
:- They do not pollute the environment.
:- E.g - Dead plants and animals, Cattle dung, urine, paper wood, seeds etc.
2. Non - Biodegradable Wastes
:- The waste materials which can not be broken down into non - poisonous or harmless substances in nature are called non - biodegradable wastes.
:- They are major pollutants of the environment.
:- E.g - DDT, Polythene bags, Plastic bags, ball point pen refill, radioactive wastes, glass objects etc.
➤ ENVIRONMENTAL PROBLEMS
1. Greenhouse Effect
:- An increase in the percentage of greenhouse gases which prevent the escape of heat from earth would increase the average temperature on earth worldwide is called greenhouse effect.
:- Greenhouse gases - CO2, CFCs ( chlorofluoro carbons), CH4, Water vapour, N2O5( Nitrous oxides).
2. Global Warming
:- An increase in earth's temperature due to increase in the concentration of greenhouse gases is called global warming.
➤ Causes
a. Carbon dioxide
:- Human activities like burning of fossil fuels etc.
b. Methane - CH4
:- Marshes, Paddy field, cattle shed etc.
c. Chlorofluoro carbons - CFCs
:- Refrigerators, A.C, Aerosol etc.
d. Nitrous oxides
:- N2O5 added to the atmosphere by organic matters and fertilizers.
* Effects
:- Melting of glaciers and polar ice caps, a rise in sea level, increase in growth of parasites and pestes, increase in precipitation and decrease in soil moisture content.
* Prevention
:- By using energy efficient devices in automobiles, by minimizing the use of fossils fuels.
b. Methane - CH4
:- Marshes, Paddy field, cattle shed etc.
c. Chlorofluoro carbons - CFCs
:- Refrigerators, A.C, Aerosol etc.
d. Nitrous oxides
:- N2O5 added to the atmosphere by organic matters and fertilizers.
* Effects
:- Melting of glaciers and polar ice caps, a rise in sea level, increase in growth of parasites and pestes, increase in precipitation and decrease in soil moisture content.
* Prevention
:- By using energy efficient devices in automobiles, by minimizing the use of fossils fuels.
:- By using recyclable & reusable products.
:- By reusing home wastes, newsprints, cardboard etc.
:- By planting more and more trees.
* Ozone layer
:- It is a thick layer of ozone gas.
:- located in stratosphere.
:- It protects us from UV radiations of sun/sunlight.
:- By reusing home wastes, newsprints, cardboard etc.
:- By planting more and more trees.
* Ozone layer
:- It is a thick layer of ozone gas.
:- located in stratosphere.
:- It protects us from UV radiations of sun/sunlight.
:- At ground level ozone is poisonous/harmful pollutant which damages plants and building materials and hazardous to human health.
3. Ozone Hole
:- The depletion of ozone layer causes ozone hole.
Note :- In 1993 about 70% of the Antarctic region Ozone was destroyed over an area about the size of North America.
* Causes
:- Ozone layer depletion takes place due to usage of ODS i.e Ozone depleting substances like -
:- CFCs(chlorofluorocarbons), aerosols, Methane or CH4, Nitrous Oxides, Chlorine and Bromine containing compounds such as - 👇
Methyl Chloroform, Carbon tetrachloride,
Halon ( industrial chemicals ) & Soil fumigants.
*Formation of Ozone Molecule
i. O2 --------> O + O ( ozone atoms )
:- Oxygen molecule breaks into free oxygen/ozone atoms by the action of UV radiation from Sun.
ii. O2 + O -------> O3 ( ozone molecule)
:- Free oxygen atom react or fuse with any molecular form of oxygen and form ozone molecule which further form ozone layer.
*Effects
:- Effects of depletion of ozone layer are as follows 👇
i. It cause diseases in humans such as Cataract, Skin cancer, dimming of eyesight, malfunctioning of Immune system.
ii. It causes mutation.
iii. It affect terrestrial and aquatic food chains.
iv. It also causes global warming.
Prevention
:- International agreement to prevent depletion of ozone layer is -👇
I. Kyoto Protocol
:- It was held in Kyoto in 1997.
Aim:- To reduce emission of green house gases at the level of 5% below the 1986/1990 level by 2008 - 2012 AD.
:- Two more conventions were also held for the same purpose such as 👇
i. Earth Summit - 1992 &
ii. Monotreal Protocol - 1987 .
:- These all international agreements are under UNEP i.e United Nations Environment Programme.
4. Acid Rain
:- When the rain falls through polluted air, it picks up more of these gases and increase its acidity that form of rain is called acid rain.
:- Polluted air contains Oxides of Sulphur and nitrogen from power stations, smelters, factories, automobiles exhaust etc.
:- pH value of acid rain is 5.6
*Effects
:- It damages plants, animals, soil, aquatic life, heritage buildings like Tajmahal & metals etc.
*Prevention :- To prevent acid rain we must have to reduce air pollution.
🚮Managing the Garbage we Produce
⚛ Garbage
:- The household wastes is called garbage.
:- It is of two types and both have to disposed off.
:- Disposal of wastes mean to get rid of wastes.
⚛ Some Scientific way of wastes disposal are as follows 👇
i. Recycling - ♻
ii. Preparation of Compost - 🔲
iii. Incineration - 🔥🎴
iv. Sewage treatment - 🔁
v. Landfill - 🚮
3. Ozone Hole
:- The depletion of ozone layer causes ozone hole.
Note :- In 1993 about 70% of the Antarctic region Ozone was destroyed over an area about the size of North America.
* Causes
:- Ozone layer depletion takes place due to usage of ODS i.e Ozone depleting substances like -
:- CFCs(chlorofluorocarbons), aerosols, Methane or CH4, Nitrous Oxides, Chlorine and Bromine containing compounds such as - 👇
Methyl Chloroform, Carbon tetrachloride,
Halon ( industrial chemicals ) & Soil fumigants.
*Formation of Ozone Molecule
i. O2 --------> O + O ( ozone atoms )
:- Oxygen molecule breaks into free oxygen/ozone atoms by the action of UV radiation from Sun.
ii. O2 + O -------> O3 ( ozone molecule)
:- Free oxygen atom react or fuse with any molecular form of oxygen and form ozone molecule which further form ozone layer.
*Effects
:- Effects of depletion of ozone layer are as follows 👇
i. It cause diseases in humans such as Cataract, Skin cancer, dimming of eyesight, malfunctioning of Immune system.
ii. It causes mutation.
iii. It affect terrestrial and aquatic food chains.
iv. It also causes global warming.
Prevention
:- International agreement to prevent depletion of ozone layer is -👇
I. Kyoto Protocol
:- It was held in Kyoto in 1997.
Aim:- To reduce emission of green house gases at the level of 5% below the 1986/1990 level by 2008 - 2012 AD.
:- Two more conventions were also held for the same purpose such as 👇
i. Earth Summit - 1992 &
ii. Monotreal Protocol - 1987 .
:- These all international agreements are under UNEP i.e United Nations Environment Programme.
4. Acid Rain
:- When the rain falls through polluted air, it picks up more of these gases and increase its acidity that form of rain is called acid rain.
:- Polluted air contains Oxides of Sulphur and nitrogen from power stations, smelters, factories, automobiles exhaust etc.
:- pH value of acid rain is 5.6
*Effects
:- It damages plants, animals, soil, aquatic life, heritage buildings like Tajmahal & metals etc.
*Prevention :- To prevent acid rain we must have to reduce air pollution.
🚮Managing the Garbage we Produce
⚛ Garbage
:- The household wastes is called garbage.
:- It is of two types and both have to disposed off.
:- Disposal of wastes mean to get rid of wastes.
⚛ Some Scientific way of wastes disposal are as follows 👇
i. Recycling - ♻
ii. Preparation of Compost - 🔲
iii. Incineration - 🔥🎴
iv. Sewage treatment - 🔁
v. Landfill - 🚮
Post a Comment