SST and History Notes XI- XII

GEO (VII)-LESSON-7

• HUMAN ENVIRONMENT-SETTLEMENT,TRANSPORT AND COMMUNICATION

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  v INTRODUCTION:

  Ø As we know that human beings are dependent on the nature for their needs as food, clothes, shelters etc.

  Ø But with time they learnt new skills to grow food, build homes and develop better means of transport and communication.

  Ø In this way they modified the environment where they lived, that refers as Human environment.

  Ø In this lesson we will read about settlement, transport and communication in human environment.

  v HUMAN SETTLEMENTS

  Ø Settlements are places where people build their homes and settle there.

  Ø Earlier settlements grew near the river valleys as the water was easily available and the land was fertile.

  Ø As we know earliest civilizations flourished along the bank of these rivers as Indus, Tigris, Nile and Hwang-He.

  
  
  
  

  v TYPES OF SETTLEMENTS

GEO (VII)-LESSON-6

NATURAL VEGETATION AND WILD LIFE

NCERT EXERCISE

1. Answer the following questions.

(i) Which are the two factors on which the growth of vegetation mostly depends?

Answer: The growth of vegetation depends on two factors: temperature and moisture.

(ii) Which are the three broad categories of natural vegetation?

Answer: natural vegetation is divided into three categories:

    1.    Forests- where rainfall and temperature are plentiful for plant growth

    2.    Grasslands- plants that grow in regions of moderate rainfall

    3.    Shrubs- plants that grow in dry regions

(iii) Name the two hardwood trees commonly found in tropical evergreen forest.

Answer: Two hardwood trees commonly found in tropical evergreen forests are rosewood and mahogany.

(iv) In which part of the world are tropical deciduous forests found?

Answer: Tropical deciduous forests, also known as the monsoon forests are found in regions that experience seasonal changes. These areas include India, northern Australia and America.

(v) In which climatic conditions are citrus fruits cultivated?

Answer: Citrus fruits are grown in regions marked for hot, dry summers and mild rainy winters. These citrus fruits include oranges, figs, olives and grapes.

(vi) Mention the uses of coniferous forest.

GEO (VII)-LESSON-6

NATURAL VEGETATION AND WILD LIFE

(LESSON NOTES)

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 GEO -(VII)-LESSON -4

NCERT EXERCISE

(i) What is the atmosphere?

Answer: The blanket of air surrounding the earth is called the atmosphere. The atmosphere primarily comprises nitrogen and oxygen in bulk and other gases like carbon dioxide, helium, ozone, etc in lesser quantities.

(ii) Which two gases make the bulk of the atmosphere?

Answer: The two gases that make the bulk of the atmosphere are:

     1.    Oxygen (21%)

      2.    Nitrogen (78%)

(iii) Which gas creates a greenhouse effect in the atmosphere?

Answer: Carbon dioxide is the gas that creates the greenhouse effect in the atmosphere.

(iv) What is the weather?

Answer: The hour to hour or the day to day condition of the atmosphere is called weather. Weather can change dramatically from day-to-day. It may be classified as hot, dry, cold or wet.

(v) Name three types of rainfall?

Answer: The three types of rainfall are as follows:

     1.    Convectional rainfall

     2.    Orographic rainfall

      3.    Cyclonic rainfall

(vi) What is air pressure?

Answer: Air pressure is defined as the pressure exerted by the weight of air on the earth’s surface. The air pressure decreases as height increases and is the highest at the sea level.

 GEO -(VII)-LESSON -3

NCERT EXERCISE

Q 1. Answer the following questions.

(i) Why do the plates move?

Answer:  The plates move due to the molten magma inside the Earth.

(i) What are exogenic and endogenic forces?

Answer: The movement of the Earth is divided on the basis of the forces, which cause them. So, the forces that act, in the interior of the earth are called Endogenic forces and the forces that work on the surface of the earth are called Exogenic forces.

(iii) What is erosion?

Answer: Erosion is defined as the wearing away of the landscape by different agents like water, wind and ice. The process of erosion and deposition creates different land-forms on the surface of the earth.

(iv) How are flood plains formed?

Answer: When a river overflows its banks, it results in the flooding of the area surrounding it. When it floods, it deposits a layer of fine soil and other material called sediments. Thus, forming a fertile layer of soil called flood plains.

(v) What are sand dunes?

Answer: When the wind blows, it lifts and transports sand from one place to another. When the wind stops blowing, the sand falls and gets deposited in the low hill-like structures. These are called sand dunes. They are mostly found in desert areas.

(vi) How are beaches formed?

Answer: The sea waves deposit sediments along the seashores. This results in the formation of beaches.

(vii) What are the ox-bow lakes?

Answer: When the river enters the plains, it twists and turns forming large bends known as meanders. In due course of time, the meander loops start to cut off the river and form cut off lakes, known as the ox-bow lakes.

GEO -(VII)-LESSON -2

INSIDE THE EARTH

NCERT EXERCISE

Q 1. Answer the following questions.

(i) What are the three layers of the earth?

Answer: The three layers of earth are :

1.    Crust

2.    Mantle

3.    Core

(ii) What is a rock?

Answer: Any natural mass of mineral matter that makes up the earth’s crust is called a rock. The earth’s crust is made up of various types of rocks of different texture, size and colour.

(iii) Name three types of rocks.

Answer: The three types of rocks are:

1.    Igneous Rocks

2.    Sedimentary Rocks

3.    Metamorphic Rocks

GEO (VII)-LESSON-1

ENVIORNMENT

NCERT QUESTION ANSWERS

Question 1. Answer the following questions briefly.

1.    What is an ecosystem?

2.    What do you mean by the natural environment?

3.    Which are the major components of the environment?

4.    Give four examples of a human-made environment.

5.    What is the lithosphere?

6.    Which are the two major components of the biotic environment?

7.    What is the biosphere?

    GEO (VII) LESSON-5

WATER

(LESSON NOTES)

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v INTRODUCTION

Ø Water is very important for our survival. It continuously changes its form and circulates between oceans and atmosphere.

Ø The Earth is called the blue planet because its 3/4^th part is covered by water.

Ø The major source of fresh water are the rivers, ponds, springs and glaciers. The ocean bodies and the seas contain salty water.

v WATER CYCLE

Ø The process by which water changes its form and circulates between oceans, atmosphere and land is known as the water cycle.

Ø The water is evaporated from the water bodies and change into water vapour due to heat of sun.

GEOGRAPHY (VII)-LESSON -3

OUR CHANGING EARTH

LESSON NOTES

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v LITHOSPHERE PLATES

Ø The lithosphere is broken down into a number of plates known as the Lithosphere plates. These plates move slowly due to some forces which causes changes on the surface of the earth. These are two forces- 

§  The forces which act in the interior of the earth are known as endogenic forces. These causes sudden movement as Earthquake and volcanic eruptions.

§  The forces which work on the surface of the earth are called as exogenic forces.These causes slow movement as weathering, erosion, deposition and gradation.

v VALCANO

Ø A valcano is a vent (opening) in the earth’s crust through which molten material erupts suddenly.