Science Do as directed; [1 M ]

Calcium Carbonate is present in marble that reacts with acids of acid rain. Acids react with calcium compounds to create gypsum which later flakes off.

Fresh water is obtained from underground water reservoirs and Rivers for human use.

Major component of atmosphere of Earth is nitrogen 79% and oxygen 20%, small fraction of carbon dioxide and other gases.
Atmosphere of Venus and Mars is composed mainly of carbon dioxide ranging from 95-97%.

Regions of north eastern India and Western ghats are rich in diversity. Western ghats start near border of Gujarat and Maharashtra, running through states of Goa, Karnataka, kerala and Tamil nadu ending at Kanyakumari. These are listed in hot-spots of biological diversity in the world.

1% of atmospheric gases are carbon dioxide and other gases on earth. Out of which, 0.03% is carbon dioxide present in the earth’s atmosphere.

Rain gauge is a device used to collect and measure the amount of rain that falls.

Sewage refers to waste and excrement of humans that is carried in sewers by municipal drains.

Detritus refers to organic matter produced by decomposition of organisms. Usually dead remains of plants and animals are detritus.

Air is called the breath of life because it contains oxygen and carbon dioxide. Carbon dioxide is used by plants to produce food and release oxygen. Oxygen is breathed in by human beings and animals to sustain life.

Global warming refers to an increase in earth’s temperature due to effect of greenhouse gases like carbon dioxide and methane.

Air currents coming from Allahabad would be directed westwards after it is intercepted by Himalaya in north due to creation of low pressure.

Resources are supply of materials that can be transformed to obtain benefit by either consuming or using.

Biosphere is living mantle of Earth which constitutes all the life forms of the planet.

Water harvesting is collection and storage of mostly rainwater into tanks or reservoirs before the water is driven away by surface runoff.

Ozone layer is called ozone umbrella/ shield because it filters out the harmful, high energy ultra violet radiations coming from the sun.

Conversion of ammonium to nitrite and nitrate by bacteria is known as nitrification.

2. Carbon monoxide has more affinity for hemoglobin because it displaces oxygen and quickly binds, thus allowing very little oxygen to be transported through body cells.

Rainwater is collected and stored into reservoirs before the rain water is lost through runoff process. This process is known as rainwater harvesting.

Dust particles present in the atmosphere forms nuclei for condensation of water vapour in atmosphere. The water vapour condense around these dust particles that further result in precipitation.

Smog is a type of air pollution occurring from emissions from vehicles and industries. This smog reacts with sunlight in atmosphere and form secondary pollutants.It lowers visibility and affects living organisms.

Air is composed of a mixture of gases such as nitrogen, oxygen and carbon dioxide. It also contains water vapours and suspended dust particles.

Inexhaustible resources are those resources that are available in abundance and cannot be exhausted ever. Eg- Air is an inexhaustible resource.

Conversion of organic nitrogen to ammonia is called as ammonification.

Air is a mixture of gases like carbon dioxide, nitrogen, oxygen and water vapour that occurs in the atmosphere.

Lichens are sensitive to Sulphur dioxide component present in air. These compounds readily dissolve in water and produce highly reactive acidic ions which disrupt photosynthesis.

Rainwater harvesting is collection and storage of rainwater into tanks or reservoirs before the water is driven away by surface run off.

Soil erosion is defined as blowing away of land surface i.e. soil by wind or water.

Cancer, arsenicosis and fluorosis are diseases caused by drinking water polluted with toxic chemicals like MTBE, arsenic and fluoride.

Incomplete combustion of carbon containing fuels like gasoline, natural gas, oil, coal etc produces carbon monoxide.

If nitrogen fixation does not take place it will disturb the nitrogen cycle. Plants will not grow if all the nitrogen from the soil is exhausted as they will not get nitrogen from the soil to grow thus creating a barren landscape. Entire food chain will be disturbed as herbivores will not have plants to eat so they will die and in turn carnivores will die because they won’t have any herbivores to feed on. If all the carnivores will die in an ecosystem, humans will also not get food, neither products from plants nor food from animal flesh.

The topmost layer of earth’s crust that supports life forms is known as soil. Soil decides the diversity of soil in a area.

Air pollution is defined as introduction of unwanted, harmful substances/ molecules into the atmosphere that harms the life forms on earth.

Carbon dioxide is the major green house gas responsible for causing global warming as it traps infrared radiations which in turn causes the earth’s temperature to rise thus causing global warming.

Carbon dioxide and methane are two greenhouse gases that are causing global warming by trapping the infrared rays and thus increasing the temperature of earth.

In coastal areas, air from high pressure area over land rushes to fill the area over low pressure area of water i.e. from land to sea.

Atmosphere is defined as layers of gases surrounding the earth surface. It is a mixture of gases like nitrogen-78%, oxygen-21% and 1% other gases.

1. Ozone layer is present in Stratosphere of the atmosphere. It protects earth from harmful Ultraviolet radiations coming from the sun.
2. Troposphere has most of the atmospheric gases. All the weather phenomenons take place in this region of atmosphere.

Detritivores are animals that feed on dead organic material like plant detritus. Earthworms, fungus are detritivore that feed on dead and decomposing organic matter.

The amount of rainfall that earth receives determines the density and richness of biota because plants need water to grow; it is one of major requirements of biota.

Mars, venus and Pluto are planets that have atmosphere. They are gas giants.

Rhizobia are soil bacteria that fix themselves in root nodules of legumes and then carry out nitrogen fixation.

The resources available on earth like air, water, food, shelter and energy from sun are major basic requirements to sustain life on earth.

Burning of fossil fuels release oxides of Sulphur, and nitrogen into the air. Nitogen gets oxidized and forms its oxides. These chemicals combine with water and fall as acid rain on earth. The pH of this rain water is less than 5.

Life is not possible on Mars and Venus because these planets have 95-97% of carbon dioxide and no oxygen to sustain life.

Cholera, typhoid and diarrhea are diseases caused by drinking water polluted with infectious agents like bacteria, viruses and protozoans.

Ozone depleting substances are responsible for ozonedepletion. Chlorofluorocarbons are such air pollutants that have chlorine atoms. 1 chlorine atom.

Environment is defined as surroundings where animals, plants and human beings function.

Nitrogen with 79% is the highest in concentration in air. Oxygen occupies 29%. 1% is occupied by carbon dioxide and other gases.

All the living organisms on the planet constitute the biosphere. The physical division of biosphere are the abiotic factors like air, soil, water, heat and light energy from the sun.

Arid areas like Rajasthan and part of Jaisalmer, Thar dessert are areas with very poor vegetation.

Weathering is breaking down of rocks to form soil by temperature, air and water.

Ozone layer blocks Ultraviolet radiations coming from sun to reach earth’s surface and thus protects us from various diseases like cataract etc.

The process by which bacteria convert organic nitrogen to ammonia is known as ammonification. After ammonification has occurred, ammonium is converted into nitrite and nitrate. Ammonification is also known as mineralization.

Carbon dioxide concentration in atmosphere is rising primarily because of two reasons:

• Deforestation.
• Increased combustion of fossil fuels.

As trees take in carbon dioxide from air and release oxygen back into the air, it helps in maintaining the desired levels of oxygen and carbon dioxide in the atmosphere. But due to deforestation, trees are being cut down and this is leading to the increase in carbon dioxide levels. The increased combustion of fossil fuels also leads to the release of enormous amounts of carbon dioxide in the atmosphere.

Energy from sun, air are examples of inexhaustible natural resources. They will not ever get exhausted.

Bacteria like Bacillus, Clostridium and Streptomyces acause ammonification. Bacillus ramosus is one such ammonifying bacteria.

When water laden air cools down it causes water to return back to its liquid state and fall on earth in the form of rainfall. So, the chief source of precipitation is water laden air.