Kerala SCERT Class 7 Social Science Chapter 7 Earth and Biosphere Question Answer Solution Here. Kerala Board Class 7 Students can find Here 7th Chapter Earth and Biosphere Notes provide by our Teacher. Important Question Answer from Chapter 7 Earth and Biosphere.
- Board- Kerala Board.
- Class – 7.
- Subject – Social Science Part 1
- Chapter – 2.
- Chapter Name – Earth and Biosphere.
- Topic – Question Answer Solution.
(A) Answer the following questions: – (marks – 1)
(1) A part of the sun get separated and exploded around ________________________
Ans: – 4500 million years ago
(2) What are the parts of biosphere?
Ans: – Lithosphere, atmosphere, and hydrosphere
(3) What is the highest peak of the world?
Ans: – Mt. Everest
(4) What is the deepest trench?
Ans: – The challenges deep of Pacific Ocean.
(5)What are the elements of soil?
Ans: – A fixed amount of water, air, humus and micro organisms
(6) It takes more than ___________ years to form one inch at soil.
Ans: – One thousand
(7) Hills are nature’s _________________
Ans: – Water reservoirs
(8) Even through two thirds of the surface of the earth is water, only __________ of it is fresh water.
Ans: – 3%
(9) Where does Ralegansidhi village situated?
Ans: – Ralegansidhi is a small village in the Ahmednagar district of Maharashtra.
(10) Which layer at air protects the Earth like a blanket?
Ans: – Atmosphere
(11) Where does Oxygen Parlour situated?
Ans: – Japan
(B) Answer the following questions: – (marks – 2)
(1) What is lithosphere?
Ans: – Hugs mountains, broad plateaus, expensive, plains, coastal areas, deserts, islands and various land forms under ocean etc. Earth’s surface is very much diverse, this solid portion of the earth which contains all the landforms, racks and soil is called the lithosphere. The highest peak, mt. Everest and the deepest trench, the challenger deep of pacific ocean are all parts of the lithosphere.
(2) What are the activities that adversely affect soil fertility?
Ans: – *Excessive use of fertilizers
*Excessive use of pesticides
*Excessive use of pesticides
*soil pollution
(3) Why did the paddy fields disappeared?
Ans: – *Vast paddy fields were once Kerala’s unique feature. But now paddy field and other wet lands undergo reclamation by being filled up with soil for human purposes. This cause permanent damage to these natural sites of rain water percolation
*In some places the clay in the paddy fields are mined and backed in.
(4) What is the reason behind the water level drops in the rivers after rainy season?
Ans: – The water level many rivers, which were once rich, drops drastically after the rainy season. This is because of the increase in the depth of river due to sand mining from rivers.
(5) What are the effects of sand mining from rivers?
Ans: – *The water level drops drastically because of the increase in the depth of river bed due to sand mining from rivers.
*It also leads to lowering of the water level in the nearby wells and ultimately to water scarcity.
*Many rivers, due to the increase in depth, have almost reached the bedrock level. This leads to bank shelving.
*Man extensively shelves river banks for sand shelwing of fertile banks results in loss of life and property.
(6) What are the activities that destroys soil?
Ans: – *Soil pollution
*Deforestation
*Excessive use of pesticides
*Excessive use of fertilisers
*Unscientific agricultural practices
(7) What is hydrosphere?
Ans: – It is known that two third of the surface of the earth is water, water, in liquid state, is found in oceans, rivers, lakes and streams, on the earth’s surface and below it as well. Water found on the earth in the said forms is cooled the hydrosphere.
(8) What are the scientific modes of water management?
Ans: – *Promote terraced farming
*Cultivate fruits bearing trees, instead of crops that have fibrous roots.
*Instead of concrete, use locally available rocks and wood to create check down along hill slopes.
*Construct earthen walls for sail conservation
*avoid construction activities and cultivation of crops like tapioca, yam etc.
*Plant trees on barren land
*Do not dump households and industrial waste into water bodies
*Protect paddy fields, ponds, lakes and river banks from reclamation.
(9) What is ‘Quenching the thirst of sail’?
Or,
How does one quench the thirst of sail?
Ans: – Most houses have concrete courtyards their courtyards with tiles. They are permanently blocking the chances of water to percolate underground. Instead of this, lay rock pieces. Grass can be grown in the spaces between the rock pieces. It will be pleasing to the eyes and there will be no hindrance for water to percolate.
(10) What is atmosphere?
Ans: – Atmosphere is a layer of air which protests the Earth like a blanket, in addition to gases like nitrogen and oxygen, atmosphere also contains dust particles and water vapour.
(11) What is the importance of atmosphere?
Ans: – *Protects from harmful ultraviolet and gamma rays
*Atmosphere contains oxygen
*Atmosphere contains CO2 that is required for plants.
*Atmosphere is responsible for climate phenomena like rain and snow.
(12)What are the reasons of air pollutions?
Ans: – *Gases used in refrigerators
*Industrial smoke
*Increase the number of vehicles etc.
(13) What is biosphere?
Ans: – Biosphere includes all living things on the Earth. Biosphere exists because of the interaction of lithosphere, hydrosphere and atmosphere. The very existence of man, plants and animals is possible because of the presence of lithosphere, hydrosphere and atmosphere.
(14) What is natural disaster?
Ans: – Natural disasters are phenomena that occur naturally and result in heavy loss to life and property of man.
(15) Give the names of Government Departments and systems for the prevention and risk reduction of natural disasters?
Ans: – *Kerala Revenue – disaster management department
*State disaster management Authority
*Hazard vulnerability and Risk Assessment cell
*Land and Disaster management Institute
(16) What do you mean by landside?
Ans: – Landside is the down-slope movement of rocks, soil and mud along the steep slopes.
(17) What are the measures to be taken when landside occurs?
Ans: – *Move to safer places as early as possible
*Give priority to small children, aged people and persons with physical disability turning rescue operation.
*Give first aid to injured people
*Be cautions of the possibility of recurrence of landside
*Contact police, ambulance services etc.
*Take precautions to avoid electric shock.
(18) What is flood?
Ans: – Surplus water during the monsoons causes overflowing of rivers leading to floods.
(19) What are the measures to be taken to tackle floods?
Ans: – *Do not construct houses very close to rivers
*Do not venture into rivers during rainy season
*Paddy fields are places for percolation of rain water. Avoid reclamation
*people residing in Coastal areas should be more careful during rainy season valuables should be shifted to elevated places
*Cut off the electric connections if the water level rises.
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