1. ENVIRONMENTAL SCIENCE
10th Grade - Biology

2. What We Study Contents :
How plants and animals are interdependent and interact with each other?
Recognise the importance of biogeochemical cycles !!
Explain the gaseous and sedimentary bio-geo chemical cycles with schematic diagram
Recall the various types and causes for environmental pollution and suggest measures to prevent the same
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Land, Air, Water & Minerals

3. INTERDEPENDENCE OF PLANTS AND ANIMALS
Living Components (Plants)
Non Living Environment
Non Living Environment
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Living Components
(Animals)
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4. INTERDEPENDANCE
Every life activity is influenced by the environmental factors and activities of the living organisms play a important role in maintaining a balance in the environmental factors.
Among the living components, plants and animals assume special significance in the ecosystem, mainly because they are linked by the food chain.
As a result, there is mutual interaction and interdependence between plants and animals. .
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Land, Air, Water & Minerals

5. INTERDEPENDANCE FROM PLANTS TO ANIMALS
A part of the carbon dioxide required by plants for their photosynthetic activity, is made available by animals. Animals release considerable amount of carbon dioxide into the environment, by way of respiration.
Plants need mineral nutrients for their life processes. They absorb these nutrients directly from the soil. A major source of these nutrients is the decomposition of dead bodies of animals.
The process of excretion by animals forms another major source of addition of nutrients to the soil.
Most of the plants are dependent on animals for processes like pollination and the dispersal of fruits and seeds.
The insectivorous plants like Drosera and Nepenthes obtain their mineral requirement, particularly nitrogen, by directly trapping and digesting insects.
Land, Air, Water & Minerals
Land, Air, Water & Minerals

6. INTERDEPENDANCE FROM PLANTS TO ANIMALS
Land, Air, Water & Minerals
Land, Air, Water & Minerals

7. INTERDÉPENDANCE FROM ANIMALS TO PLANTS
Animals on the other hand, are totally dependent on plants for their food,
either directly or indirectly.
* Herbivorous animals directly consume plant material from which they obtain
all their essential nutrients.
* Carnivorous animals obtain their food from the consumption of other animals.
Even in these animals, the primary nutrient source will be plants.
* Animals require oxygen for carrying on respiration. The major source of
this oxygen is the process called photosynthesis seen in green plants.
* Plants, particularly trees, provide shelter to a wide variety of animals. Many
animals use the trees as their habitat
Land, Air, Water & Minerals
Land, Air, Water & Minerals

8. INTERDÉPENDANCE FROM ANIMALS TO PLANTS
Land, Air, Water & Minerals
Land, Air, Water & Minerals

9. BIOGEOCHEMICAL AND TYPES OF CYCLES
“The Various Chemical Substances moves in the ecosystem in a cyclic manner continuously being exchanged between non –livin gand Living components. Such Chemical substances is called as Biogeochemical Cycles”
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Gaseous Cycle
The reservoir pool will be Atmosphere or Hydrosphere
Sedimentary Cycle
The Reservoir Pool will be the Lithosphere
Reservoir Pool
A Cycle where the movement of Chemical Substances is very slow and involves non –living things
Exchange Pool
A Cycle where the Movement is Rapid and involves living organisms
Biogeochemical Cycles
Carbon Cycle
Nitrogen Cycle
Phosphorous Cycle
Sulphur
Cycle
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10. GASEOUS CYCLES : CARBON CYCLE
Carbon is a basic element for all life and is an essential constituent of all organic compounds that compose the protoplasm. Atmospheric carbon dioxide serves as the source of carbon for the synthesis of organic compounds, particularly sugars, in autotrophic land plants. In aquatic ecosystems, carbonates and bicarbonates dissolved in water serve as the source of carbon. Photosynthesis, is thus, responsible for the fixation of carbon into the nutrient pool.
Following are the main steps in carbon cycle in nature.
The major biological process by which carbon dioxide is fixed from the reservoir pool, is photosynthesis.
Green plants are consumed by herbivores and herbivores in turn are consumed by carnivores. Thus, carbon in the form of plant biomass travels as food to the animals in the successive trophic levels.
Respiration by plants and animals releases carbon dioxide as a by-product. When these plants and animals die, their dead bodies are decomposed to release carbon dioxide.
Some of the dead plants and animals which get buried deep under the earth’s crust, escape oxidation and change into ‘fossil fuels’ like petroleum, through very slow chemical changes. When such fuels are burnt, they release carbon-dioxide.
Occasional volcanic eruptions also release gaseous carbon dioxide into the atmosphere.
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Land, Air, Water & Minerals

11. GASEOUS CYCLES : CARBON CYCLE
Land, Air, Water & Minerals

12. GASEOUS CYCLES : NITROGEN CYCLE
Nitrogen is one of the essential component of biological molecules such as proteins and nucleic acids with (79%) in the atmosphere. However, this gaseous nitrogen cannot be directly utilized by the organisms in the exchange pool.
The process of converting free gaseous nitrogen of the atmosphere into useful forms of compounds of nitrogen, is called nitrogen fixation. It occurs in two ways namely, natural fixation and artificial fixation.
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Note :
Ammonification is the conversion of complex organic compounds like proteins into ammonium salts. This process is brought about by a group of soil bacteria, called ammonifying bacteria. Even the nitrogenous waste products released by animals during excretion, are subjected to ammonification. Nitrification is the conversion of ammonium salts into nitrates and nitrites. Nitrification is brought about by another group of bacteria called nitrifying bacteria. Bacteria such as Nitrosomonos oxidise ammonium salts into nitrites. Bacteria such as Nitrobacter further oxidise nitrites into nitrates. Denitrification is the conversion of nitrates in the soil into free gaseous nitrogen. It is brought about by a group of bacteria called denitrifying bacteria, such as Pseudomonos. Such bacteria decompose a part of the nitrates in the soil and water into gaseous nitrogen which is recycled back into the atmosphere
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13. GASEOUS CYCLES : NITROGEN CYCLE
Natural Fixation
Artificial Fixation
Biological fixation : It is the process which involves fixation of nitrogen directly by organisms such as bacteria and blue green algae. Soil bacteria as occurring in ponds and paddy fields, also have the capacity to absorb and store atmospheric nitrogen. Nitrogen fixed by such living organisms is carried into the soil. Rhizobium enter the roots of leguminous plants and get lodged there. They absorb atmospheric nitrogen directly and store it in the roots, forming swellings called root nodules. Leguminous plants use this nitrogen for biosynthesis of proteins. Blue-green algae such as Anabaena and Nostoc
Artificial fixation involves the combining of atmospheric nitrogen with gaseous hydrogen to form ammonia. This ammonia can be oxidised to form nitrates or The recycling of nitrogen involves certain biological processes likeand ammonium salts contain fixed nitrogen which can be absorbed by plants. It can be reacted with acids to form ammonium salts. These nitrites ammonification, nitrification and denitrification carried out by the bacteria in the soil.
Electrochemical fixation : It is the process by which nitrogen is fixed by a non-biological, natural process. It occurs during lightning in the sky. Due to the high temperature formed, nitrogen combines with oxygen to form nitrogen oxides. These oxides dissolve in water to form a dilute solution of nitric acid which acid reacts with alkalies in the soil to form nitrates which are absorbed by plantscondenses down to the earth with rain water.
Land, Air, Water & Minerals
Land, Air, Water & Minerals

14. GASEOUS CYCLES : NITROGEN CYCLE
Land, Air, Water & Minerals

15. GASEOUS CYCLES : OXYGEN CYCLE
Atmospheric
Oxygen
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16. ENVIRONMENTAL POLLUTION
Definition : Undesirable change in the physical, chemical and biological characterstics of the environment. . Such changes are caused by substances that are introduced into the environment by human activities called as pollutants.
Biodegradable pollutants : Biodegradable wastes decompose into soil.
Kitchen food scraps
Garden waste
Paper and egg shells
Human and animal waste
cardboard boxes
Non-degradable pollutants : Non-biodegradable wastes take a long time or never to decompose.
Metal cans
Bottles
Toxic chemicals
Plastic products
Metal scraps
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17. Types of Pollution Air Pollution Water Pollution Soil Pollution
Noise Pollution
We can recognize other forms of pollution such as noise pollution, thermal pollution, radio-active pollution etc
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18. Air Pollution
“An increase in any of the constituents of the atmosphere which is harmful to the living beings and their environment, is known as air pollution”
We burn fire wood in our houses and coal in factories, petrol in vehicles. In all these cases carbon dioxide, carbon monoxide and other gases are released into the atmosphere. If these gases reach a concentration which becomes harmful to us or to the environment, then we can consider the air to be polluted
Examples : Smog, Acid rain, Indoor Pollution, Dust Particles
Know it : Poisonous Gases : CO, CO2 ,Carbonyl chloride, Ammonia, Hydrogen Sulphide and cyanides. NO. SO2 Hydro carbons
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19. Air Pollution
Industries, automobiles and modern agricultural operations release a large number of chemicals, smoke, dust and poisonous gases into the atmosphere.
Some of the toxic gases undergo photochemical reactions with the oxides of nitrogen in the atmosphere to generate photochemical smog. Smog is a combination of smoke and fog.
Smog formation is common in many industrial cities like Mumbai, Kolkatta, Delhi and Bangalore. These gases (SO2 and SO3) when released into atmosphere react with rain water to form acids, which come down as acid rains
Land, Air, Water & Minerals

20. Effects of Air Pollution
Human Health
Vegetation
Building & Monuments
Climate
Polluted air causes respiratory disorders such as bronchitis and allergies
It increases the acidity of soils.
Acid rains and smog can damage historical Monuments
level of air pollution has increased due to the excessive use of fossil fuels and large scale destruction of forests. This has led to a rise in the global temperature.
Smog is a killer precipitation. It can cause bronchial afflictions that may lead to death
Air pollutants inhibit the growth of Lichens on trees.
One of the air pollutants Chlorofluro carbons (CFCs) can oxidise rubber goods.
This phenomenon is similar to the one taking place inside a glass house, where plants are grown. Hence, this phenomenon is called the “Green house effect”.
Carbon monoxide combines with haemoglobin and impedes oxygen transport in the blood
Acid rains can damage or destroy forest trees.
World famous architecture of St. Paul cathedral is getting spoiled for about 1 inch every 100 yrs
The famous stone sculptures of Greece and Italy and the world famous liberty statue are losing their lustre.
If this rise in temperature is more than 2 or 3 degrees, it may lead to the melting of polar ice caps and glaciers causing a rise in the level of water in the oceans.
Be Aware : The ozone layer is becoming thin due to the gases called CFC. CFCs are known to spoil the ozone layer of the earth in a systematic way. 1 molecule of CFC can destroy 1 Lakh molecules of Ozone. The ozone layer acts as a natural filter and prevents excessive radiation from the sun, reaching the earth. Air pollutants such as CFCs can damage the ozone layer and are believed to cause skin cancer and mutations
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21. Controls of Air Pollution
Air pollution can be controlled by a thorough understanding of its causes.
Establishment of industries away from the towns and cities.
Increasing the length of the chimneys in industries.
Growing more plants and trees
Use of efficient engines in automobiles.
Use of smokeless choola.
Use of petrol without lead (unleaded petrol)
Enforcement of regulatory rules of air pollution and rigorous punishment to the defaulters
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22. Water Pollution
“Effluents from various industries, sewage containing domestic wastes and
pesticides from agricultural lands are finding their way into water bodies leading to water pollution”
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23. Causes of Water Pollution
Industrial wastes : Various kinds of industries like paper mills, sugar factories, iron and steel industries, food processing industries, fertilizer factories, textile mills, electroplating industries and chemical plants release waste waters into the neighbouring water bodies like rivers and lakes. These waste waters often contain toxic materials like cadmium, lead, chromium, mercury, fluorine, acids and alkalies.
Sewage water : Sewage contains human and animal excreta in addition to food residues, detergents and other wastes. It is rich in disease causing bacteria and organic substances. Addition of sewage water into natural water bodies seriously affects the quality of water. Rivers like Ganga, Narmada, Kaveri, Godavari, Tungabadhra, Brahmaputra, Krishna and Mahanadi are now known to be highly polluted.
Agricultural wastes : These wastes contain residues of fertilizers and pesticides which get very easily carried into the nearly water bodies.
Release of superheated water : Release of superheated water from some industries and nuclear power plants results in thermal pollution in natural water bodies.
Addition of waste and oil from refineries : Wastes from refineries and oil released into seas and oceans, cause marine pollution which is detrimental to marine life.
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24. Causes of Water Pollution
Industrial pollutants like mercury, chromium, cadmium and lead are poisnous. They are also capable of entering the food chains and cause diseases in man, Mercury is known to cause a disease called Minamata. It causes initial numbness of limbs, lips and tongue. Finally it leads to impairment of motor control, deafness, blurring of vision, cellular degeneration in the brain, spasticity, coma and death.
Organochlorine pesticides like D.D.T in the agricultural wastes are non-degradable and move along the food chains. It may lead to biomagnification.
Some industrial effluents can cause hanges in the colour, odour and taste of water in the natural water bodies.
Contamination of water also leads to spread of water borne diseases such as cholera, amoebiasis and other diseases.
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25. Control of Water Pollution
Sewage treatment : It is done in three steps. In the first step suspended materials are removed. In the second step, the waste water is aerated. This promotes bacterial decomposition of organic compounds. This is followed by chlorination. In the third step, nitrates and phosphates are removed and the water is purified.
Effluent Treatment : Industrial effluents are suitably treated to eliminate the pollutants. The steps involve removal of toxic chemicals, neutralization of acids and alkalies, precipitation of metallic compounds and reducing the temperature of waste waters from power plants.
Land, Air, Water & Minerals

26. Soil Pollution
Various kinds of domestic wastes, residues of pesticides and fertilizers have
been the major sources of soil pollution. There is also the risk of some of these residues entering into food chains in the neighbouring water bodies.
Pesticides like B.H.C., D.D.T, etc. contain non-degradable poisonous constituents which enter the human body through food chain.
CAUSES OF SOIL POLLUTION
1. Excavation of earth, especially in towns and cities for construction of new buildings
2. Residues from the factories.
3. Indiscriminate use of pesticides.
4. Addition of non degradable domestic wastes like plastic
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27. Control of Soil Pollution
Minimising the usage of pesticides.
Periodic change of crops to increase the soil fertility.
Disposal of unwanted garbage created by clinics and hospitals properly either by burning or by burying into the soil.
Minimising the usage of plastics.
Following the rules and regulations laid down by pollution control board.
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28. Noise Pollution
“Improvement in human civilization has resulted in the use of various kinds of vehicles for transport purposes. Such vehicles have today become a major source of noise pollution”
In addition the use of microphones and other audio-equipment in public places have added to the intensity of noise pollution which has a direct effect on human health.
EFFECTS OF NOISE POLLUTION
It affects human nervous system leading to deafness, headache, blood pressure, brain disorders etc.
Harsh noise leads to uneasy feelings, short temper, heart disease, and other
related problems.
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29. Control of Noise Pollution
MEASURES TO CHECK THE NOISE POLLUTION :
Replacing very old machines by new ones.
Providing labourers in industries with ear plugs and improved sound proof instruments.
Parking for high sounding vehicles should be only outside the city limits.
Regulation of loud speakers used in functions.
Growing broad-leafed plants which can absorb sound
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