I.Choose the correct answer:
1. The surrounding inwhich organisms live and interact is called Environment.
2. The process of clearingthe forests by human is called as Deforestation.
3. The process by whicheco system species become extinct is Loss of biodiversity.
4. The excessive use ofartificial fertilizer greatly reduces the quality of soil.
II.Match the following:
1. Global warming -CO2
2. Deforestation -Coastalflooding
3. Automobile -airpollution
4. Water pollution-pesticides
5. Urbanisation-unauthorized encroachments
III.ANSWERIN BRIEF:
1. What are the major environmental issues?
- Urbanization
- Deforestation
- Environmentalpollution
- Globalwarming
2. What is global warming?
Global warming is definedas an increase in the atmospheric temperature near the earth surface due torise in carbon dioxide levels and green house effects.
3. What is Deforestation?
Deforestation simply meanscutting down a tree.
It has seriously affectedthe quality of environment by increasing the temperature, decreasing rainfall,top soil erosion, flash flood.
4. Name some of green house effect?
Carbon-di-oxide, Methane,Nitrous oxide and Chloro-fluoro-carbon.
5. What is pollution?
Substances released intoan environment that cause harm to living organism and built up structures arecalled pollution.
6. What is urbanization?
It refers to increasinginhabitants of people with non agricultural occupation with a higher populationdensity than the surrounding regions.
7. What are the main threats to biodiversity?
Uncontrolled commercialexploitation of natural resources like forest, coastal areas, wet lands.
8. What are the sources of land pollution?
Land pollution is thecontamination of land by solid wastes.
IV.ANSWER THE FOLLOWING:
1. What are the effects of the global warming?
Heat waves and fluctuatingweather causes diseases and warming up of Antarctic and Arctic ocean.
Sea level rise coastalflooding due to glaciers melting coral reefs bleaching due to the change in theecosystem frequent drought fire and heavy snowfall.
2. What is the main objectives of the biosphere reserves?
The main objectives of thereserves is to conserve the genetic diversity of species and to restoredegraded ecosystems to their natural and original conditions.
To protect the biosphere,biosphere reserves have been set up in the Nilgiris and Gulf of Mannar.
3. Mention the areas of water pollution in Tamil Nadu and whatsteps have been taken by the government to stop it?
- Theindiscriminate discharge from textile bleaching and dyeing units in and aroundTiruppur, Erode and Karur areas have caused polluting the river system ofNoyyil and Amaravathi
- Effluentsfrom tanneries for land quality deterioration in the river palar basin ofVellore district
- Mosttowns located along the banks of major rivers causes sewage pollution.
- TheKaveri river receives sewage from eleven towns, Palar from six towns, Vaigaifrom five towns and Tamirabarani from three towns.