17 April, 2015

Class VII: Chapter 1 - Our Environment

Important term to remember:

1.      Environment: The immediate natural surroundings of man is called environment. E.g.: Plants, Air, Water, Landforms, Wildlife, etc.......

The word Environment has been derived from a French word "Environner" which means "Neighborhood".

2.      Components of Environment:

 (a) Natural Environment               (b) Human Environment        (c) Human Made Environment

 

3.      Biotic Components: All living things are known as Biotic Components. E.g.: Plants, Animal Kingdoms including man, etc....

4.      Abiotic Components: All non-living things are known as Abiotic Components. E.g.: Air, Water, Land, etc.....

5.      Ecosystem: Interrelation between plants and animals in the natural environment is called Ecosystem.

6.      Ecology: The Science with studies the relationship between living and non-living environment is termed as Ecology.

7.      Domains of Earth: The Four domains or realms of the Earth which jointly support life are: -

         (a) Atmosphere     (b) Hydrosphere         (c) Lithosphere          (d) Biosphere

8.     Biosphere: Plant and animal kingdom together make Biosphere or the living worlds. It is a narrow zone of the Earth where Air, Water and Land interact with each other to support life.

 

Geography studies the interrelationship between human beings and the environment.

 

Natural Environment:

1. Lithosphere

  • It is the solid crust or the hard top layer of the earth.
  • It is made up of rocks and minerals and covered by a thin layer of soil.
  • It is an irregular surface with various landforms such as mountains, plateaus, plains, valleys, etc. Landforms are found over the continents and also on the ocean floors.
  • Lithosphere is the domain that provides us forests, grasslands for grazing, land for agriculture and human settlements. It is also a source of mineral wealth.

2.Hydrosphere

  • The water bodies on the earth's surface together form the Hydrosphere. E.g. Seas & Oceans, Rivers, Lakes, etc.
  • Earth is also known as "Watery Planet", because 71% of it's surface is covered with water.
  • Water is used for various purposes, i.e. domestic, agriculture, industries, transportation, generating electricity, etc.

3.Atmosphere

  • The gaseous envelope around the earth's surface consisting of mixture of gases, water vapour and tiny dust particles is called atmosphere.
  • Atmosphere is endless with no visible boundary.
  • Atmosphere is composed of various gases. Major gases present are: Nitrogen – 78%, Oxygen – 21%, Argon - .93%, Carbon Dioxide – 0.03%, Other Gases – 0.04% (like – helium, hydrogen, methane, ozone, etc. and water vapours & dust particles.
  • Ozone layer protects us from harmful ultraviolet rays of the sun.
  • It acts as a blanket which prevents the earth from becoming too hot during day and too cold during night.

4.Biosphere

  • Plant and animal kingdom together make biosphere or the living world.
  • It is a narrow zone of the earth where Land (Lithosphere), Water (Hydrosphere) and Air (Atmosphere) interact with each other to support life.
  • Biosphere makes the earth a unique planet in the solar system.

 

 

ECOSYSTEM

  • All plants, animals and human beings depend on their immediate surroundings. Often they are also interdependent on each other.
  • This relation between the living organisms, as well as the relation between the organisms and their surroundings form an ecosystem.
  • There could be an ecosystem of large rain forest, grassland, desert, mountains, lake, river, ocean and even a small pond.
  • In every ecosystem, there is a perfect balance in the transfer of energy and matter among the different components. This is known as Ecological Balance. 

 

ELEMENTS OF BIOSPHERE

 1.  Elements of Biosphere:Basically there are three elements of Biosphere: -

(a)  Producers      (b)  Consumers        (c)  Decomposers

(a) Producers: Plant Kingdom.

(b) Consumers:

     (i)   Herbivores: First consumers, plant eating animals. E.g. goat, dear, etc. They are large in number and reproduce faster.

     (ii)  Carnivores: Second level consumers. Flesh eating animals. E.g. lion, tiger, etc. They have sharp teeth and claws and reproduce at a slower rate.

     (iii) Omnivores: Consumers. They eat both plants and animals. E.g. man, ant, etc

(c) Decomposers: Microorganisms like bacteria get their food from dead plants and animals by decomposing them and are known as Decomposers. They keep the natural environment clean because they convert the dead matter of plants and animals into simple compound which then enter the soil and air.

 2.      Food Chain: In the process of consuming plants by herbivores and herbivores by carnivores, there is a transfer of energy from one level to another, which is called Food Chain.

 

 

HUMAN ENVIRONMENT

  • Human beings are the most important part of environment. They not only interact with the environment but also modify it according to their needs.
  • Early humans adapted themselves to the natural surroundings. They led a simple life and fulfilled their requirements from the nature around them. With time needs grew and became more varied.
  • Modifications done by human beings have disturbed our ecosystem. Man is responsible for degrading the environment. Deforestation, Soil Erosion, etc. are some of the important factors.
  • Humans must maintain balance between natural and human environment. Resources to be used wisely and should be preserved for future.

 

World Water Day: World Water Day is celebrated on 22 March every year.

World Environment Day: World Environment Day is celebrated on 05 June every year.

 

"LET'S JOIN OUR HANDS TOGETHER TO MAKE OUR ENVIRONMENT CLEAN AND GREEN"

 

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Comments

Hemant Bhatt13 September, 2013Great effort Sir. Lots of research and compilation done. Keep it up!!!
sushil yadav13 September, 2013its very informative.
pratyush pandey30 April, 2014thanks a lot,I hope you remember me I am the boy with whom you talked on our way to Mandvi.
Subhash Kr. Nirmhan30 April, 2014Yes, I do remember you Pratyush. Good to see you surfing the site....hopefully you find it informative... Keep working hard....God bless you dear....
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Animesh kumar18 June, 2017This is good I am very happy to you
Uzma Khan 18 June, 2017Osm
fghj15 June, 2018nice information
Palak 14 July, 2018Very nice you have send me All chapter of the social science
Somya17 July, 2018Very nice it have all answer

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