I. KEY WORDS:
1. Food chain: One kind of life becomes food for another kind. Many of the life exchanging essential substances with each other.
2. Hard wood trees: Hard wood trees are extremely useful for making furniture, transport and constructional materials. Rosewood,
ebony, mahogany, sal, teak, neem and shisham etc.,
3. Acid rains: The precipitation accrued with sulfuric acid and nitric acid. These substances reaches into the atmosphere and mix and with water, oxygen, and other chemicals to form known as acid rain.
4. Ecological crisis:
5. Tundra: The region within the Arctic circle covered with snow and extremely cold is known as tundra.
II. Short Answers:
1. What is Global warming ?
A.
Earth's average surface temperature due to effect of greenhouse gases such as carbon dioxide emissions from burning fossil fuels .
2. What is meant by ' Biosphere ' ?
A.
According to many geographers , life itself constitutes a separate sphere called " biosphere's
3. Into how many categories is the natural vegetation classified ? What are they ?
A.
Natural vegetation is generally classified into three broad categories .
1. They are forests ,
2. Grasslands and
3. Shrubs
4. What are the factors influences nature of the forests?
A.
They are:
1. Rainfall,
2. Temperature,
2. Soil Type,
3. Relief feature
5. Write the names of trees and animals in the coniferous forests .
A.
Important trees are Chir, pine, cedar.
Important animals are Silver fox, mink, polar bear.
6. Write the reason of acid rains?
A.
Acid rains are caused by the mingling of acidic particles of the atmosphere with the rain by increasing the acid content of rain water .
7. How is mediterranean climate and vegetation are different ?
A.
1. Mediterranean regions are marked for hot dry summers and mild rainy winters.
2. Citrus fruits such as oranges, figs, olives and grapes are commonly cultivated here .
3. Vegetation here adapt themselves to dry summers with the help of thick bark and wax coated leaves, which help them reduce transpiration.
4. Vegetation in other regions shed their leaves.
8. What is called Savannah grass lands?
A.
1. Tropical grasslands in Africa on either side
of the equator and extend to the tropics called Savannah.
2. This grows in areas of moderate to low rainfall.
3. The grasses grow very tall, about 3 to 4 metres in height.
9. What are the factors influences nature of the forests?
A.
They are:
1. Rainfall,
2. Temperature,
2. Soil Type,
3. Relief feature
10. What is Greenhouse effect ?
A.
1. The earth radiates heat it receives from the sun into the sky.
2. The greenhouse gases such as carbon dioxide, methane, chloro flouro carbons trap the heat reflected by the earth into the sky and thus maintain a constant surface temperature .
3. This mechanism is known as Greenhouse effect.
11. Write about Steppes grassland?
A.
1. Temperate grasslands in Eurasia is known as Steppes.
2. These are found in the mid-latitudinal zones and in the interior part of the continents
3. Usually, grass here is short and nutritious.
12. What doyou know KYOTO PROTOCOL?
A.
1. To protect mother earth from global warming. A conference was held in the city of Kyoto in Japan in December 1997 by the UNO
2. The countries that attended realised the effect of Green House Gases and signed a declaration called Kyoto Protocol.
3. The main aim of this declaration is
to bring down the release of Green House
Gases to less than 5.2%. by between 2008-2012.
13. What is Global warming ? What are the reasons for global warming ?
A.
Earth's average surface temperature increases due to effect of greenhouse gases such as carbon dioxide emissions from burning fossil fuels.
Reasons for global warming :
1.Release of carbon dioxide into the atmosphere by power plants by burning the fossil fuels and burning gasoline by automobiles.
2.Methane emissions from animals agriculture . 3.Deforestation especially tropical forests for wood, pulp and farmland.
4.Increase in usage of chemical fertilizers on croplands.
III. IMPROVE YOUR LEARNING:
1. Life itself constitutes a separate sphere called 'Biosphere'. Explain.
A.
1. The Earth is a unique planet, in that it has life.
2. It is inhabited by countless forms of life from microscopic bacteria to great banyan trees and aniamals like lions and blue whales and human beings.
3. The earth has a combination of land , air and water and a moderate temperature and distance from the Sun has made life possible on it.
4. They influence one another and they are part of a complete "food chain".
5. Some geographers constituted this sphere as a separate sphere called biosphere.
2. Why is ecological crisis occured in modern times? What are its effects?
A.
1. Ecological crisis occurs when changes in the environment of a species or population destabi lises its continued survival.
2. To satisfy the needs of ever growing population systematic mining, cutting of forests, building roads took place all over the earth.
3. With the advent of the industrialisation and population growth contaminate air, water and soil.
4. This meant that the reshaping of the surface of the earth received a great push.
5. Industrial production needed raw material on an unprecedented scale.
6. For providing food for the ever growing population, chemical fertilizers and pesticides are used agriculture.
All these factors lead to ecological crisis
Effects of ecological crisis :
1. If a particular species which feeds upon a particular kind of plant is exterminated, it would result in unchecked growth of that plant and it may intrude the area where other plants grow and disturb their growth.
2. The metals like mercury which is released by industries into rivers are consumed by microorganisms and in turn beome the food of fishes. While human beings consume, they too absorb some amount of mercury which is detrimental to their health
3. Diclofenac is used to treat cattle, their flesh retains this chemical after they die. Their flesh is consumed by vultures, leads to kidney failure and they die .
3. Write about the different kinds of forests and climatic conditions of their existence ?
A.
I. Tropical Evergreen Forests:
a. These are found in the regions near the equator and close to the tropics.
c. This region hot and receive heavy rainfall throughout the year.
d. Trees do not shed their leaves altogether since there is no dry season.
II. Tropical Deciduous Forests:
a. These forests are also known as monsoon forests, found in large parts of india. Australia and central America.
b. These regions experience seasonal changes.
c. Trees shed their leaves in the dry season to conserve water.
III. Temperate Evergreen Forests:
a. These forests are located in the mid latitudinal coastal regions.
b. They are commonly found along the eastern margin of the continents.
IV. Temperate Deciduous Forests:
a. These forests are located in the mid latitudinal costal region.
b. They are commonly found along the eastern margin of the continents.
V. Coniferous Forests:
a. Coniferous forests are found in the higher latitudes of (50°-70°) Northern hemisphere.
b. These forests are found in abundance in the Himalayas .
c. They are tall with needle like leaves, softwood evergreen forests.
4. How can we protect natural resources ?
A.
1. Industrialisation, rapid growth of population and urbanisation have all led to unprecedented exploitation of natural resources like minerals forests, soil, water, air, etc.
2. Scientists predict that the rate being used at which these resources are soon will be depleted.
3. We should use methods of sustainable growth in all fields of development.
4. Countries should join hands in using their resources in a limited manner.
5. They should become interdependent, share their conservational technology with each other.
6. Conservation should be in the field of soil, increasing of forest cover, using renewable or recyclable energy resources.
7. Conservation methods only save our environment but also fulfill the needs of our future generation.
5. Read the chapter and fill up the table
A.
7. Read the paragraph under the title " In addition to ........ and soil on page 57 and comment on it.
In addition to burning of fossil fuels, modern industries release enormous amounts of waste materials in the form of solid, liquid and gaseous waste contaminating air, water (both surface water like rivers and underground water of wells) and soil.
A.
1.Modern industries and transport system use adequate amount of energy.
2.They release enormous effluents of waste materials in the form of solid, liquid and toxic waste contaminating air, water and soil.
3.They also release of sulfuric carbonic and nitric acids, which cause what are called "acid rains".
4.The buring of fossil feuls releases large quantities of carbon dioxide and other chemicals like nitrogen oxides, sulfur dioxide, carbon monoxide, volatile organic compounds and heavy metals.
8. Mark the following locations on the given World Map.
a) New Zealand b) Brazil c) Australia d) North America e) China f) India
A.
