7.Class.Chapter1.Geo.Classnote.Components of Environment

 Chapter 1.Geography

COMPONENTS OF ENVIRONMENT
Keywords
Biodiversity -  It is a variety of of life on earth comprising of plants, animals and micro-organisms.
Microbes - A very small organisms.
National park - A well demarcated reserved area for the protection of wildlife. It does not allow any human activity.
Ocean- A vast expense of saline water on the earth’s surface.
Wildlife Sanctuary- A geographical area meant for the conservation of biodiversity.Limited human activities are permitted.

Internal questions
Q.1.What is environment?

A.1.Environment in its true sense can be defined as all that surrounds us. Environment is our basic life support system.
Q.2.Name the four spheres of the environment.
A. The four spheres of the environment are lithosphere , biosphere, hydrosphere  and  atmosphere.
Lithosphere  means  sphere  of  rocks.
Biosphere  mean  the  sphere of life.
Hydrosphere is the sphere of water.
Atmosphere is the sphere of air.
Q.3.What are the Types of Lithosphere.
A.3.There are two types of Lithosphers.
a.Sial-The uppermost part of the lithosphere composed of rocks rich of  silica and aluminium is called Sial layer.
b.Sima -Below the sial layer the rocks are composed of silica and magnesium is called Sima.
Question Answers.
A.Tick the correct option
1.Which one is not a part  of biological environment;
Ans.Water.
2.Volcanoes erupt  due  to;
Ans. Internal disturbance of the earth.
3.Which  one  bring a sudden  change  in  the  environment;
Ans. Rainfall.
4.Identify  by  the term  that  stands  for  the  topmost  layer  of the earth  comprising  of  loose  material;
Ans.Soil.
5.In which year was the wildlife protection act passed in India;
Ans. 1972.

B .Give a single term for each of the following sentences.
1. A situation or condition in which an organism lives.
Ans. Biosphere.
2.The only planet in our solar system where life exists.
Ans. Earth.
3.The uppermost part of the lithosphere which is rich in silica and aluminium.
Ans. Sial.
4.The sphere of air that envelopes the air.
Ans. Atmosphere.
5.Mass of water of the earth’s surface.
Ans. Hydrosphere.

C.Match the following.
1.Physical environment includes
Ans. Non living things.
2. It is the most dynamic in nature.
Ans. Atmosphere.
3. A narrow zone supporting life.
Ans. Biosphere.
4. They are capable of modifying  environment.
Ans. Human beings.
5.Rocks rich in silica and magnesium.
Ans. Sima.

D.Answer the following in the brief.
Q.1.Name the major components of the environment.
Ans.The major components of  the  environment  are -
Lithosphere, Hydrosphere, Atmosphere and Biosphere.
Q.2.What is meant by Sima and Sial?
Ans. Sial,the uppermost part of the lithosphere is known as Sial.

Sima -Below the sial layer the rocks are composed of silica and magnesium is called Sima.

Q.3.Mention the distribuition of water in the Northern and Southern hemisphers.
Ans.43 Percent of water lies in the  northern hemisphere and 57 per cent of water  covered in   southern hemisphere.
Q.4. Give the literal meaning of  the four spheres of the environment.
Ans.1.Lithosphere  means  sphere  of   land 

2.  Hydrosphere  means  sphere  of  water  

3.  Biosphere  means  sphere  of  life  

4.  Atmosphere  means  sphere  of  air.
Q.5. What is  atmosphere composed of .
Ans. The Atmosphere  is   composed  of  a  mixture  of  gases.

E.Answer the following questions
Q.1. Differentiate between  physical and biological environment.
Ans.Physical environment-- Physical environment  includes  non living things  like land, water and air.
Biological  environment -- Biological  environment  includes  all living  things  like human  beings,plants  and  animals.
Q.2.Why is earth called ‘ the Blue Planet ’
Ans.  Earth is known as Blue Planet because  of  abundance of water on its surface . 70 per cent of  of  the  earth  is  covered  by  water.
Q.3.Define biosphere. Why is it important for us.
Ans.  Biosphere means sphere of  life  and  it  is the  narrow  zone of contact between all the three spheres of environment where all kinds of  life  exist.
Without biosphere no one can live in the earth.
Q.4.Explain with the help of an example how physical and biological components of the environment are interdependent.
Ans.  Physical and biological environment are interdependent and cannot be separated.Any major change in the  physical environment is bound to bring a change in the accompanying biological environment. Man is the most important component of the biological environment who satisfies all the required needs from both parts of the environment.
Q.5.Explain two ways in which human being are disturbing the natural environment.
Ans.The  two ways in which  human being are disturbing the natural environment are;

1.Deforestation - Due  to rapid increase in population of the world the area under the forest are fast decreasing. Man has cleared forests for the sake of agriculture, habitation and the expansion of industries.

.2.Global warming.- The pollution level in different countries is rising alarmingly and there is a considerable rise in global temperature. A few glaciers have also started melting in the polar ice - caps.