Class 11 Geography Chapter 11 NCERT Textbook Questions Solved

1. Multiple choice questions.

Question 1(i).
Which one of the following is the most important constituent of the atmosphere for human beings?
(a) Water vapour
(b) Nitrogen
(c) Dust particle
(d) Oxygen.
Answer:
(a) Water vapour

Question 1(ii).
Which one of the following process is responsible for transforming liquid into vapour?
(a) Condensation
(b) Transpiration
(c) Evaporation
(d) Precipitation.
Answer:
(c) Evaporation

Question 1(iii).
The air that contains moisture to its full capacity:
(a) Relative humidity
(b) Specific humidity
(c) Absolute humidity
(d) Saturated air.
Answer:
(d) Saturated air.

Question 1(iv).
Which one of the following is the highest cloud in the sky?
(a) Cirrus
(b) Stratus
(c) Nimbus
(d) Cumulus.
Answer:
(a) Cirrus

2. Answer the following questions in about 30 words.

Question 2(i).
Name the three types of precipitation.
Answer:
There are many forms of precipitation like dew, fog, rainfall, snowfall, hailstones etc.

• Rainfall: The precipitation in the form of water is called rainfall.
• Snowfall: When the temperature is lower than the 0°C, precipitation takes place in the form of fine flakes of snow and is called snowfall.
• Hailstones: Sometimes, drops of rain after being released by the clouds become solidified into small rounded solid pieces of ice and which reach the surface of the earth are called hailstones.

Question 2(ii).
Explain relative humidity.
Answer:
The percentage of moisture present in the atmosphere as compared to its full capacity at a given temperature is known as the relative humidity. It is highest over oceans and lowest over continents. With the change of air temperature, the capacity to retain moisture increases or decreases and the relative humidity is also affected.

Question 2(iii).
Why does the amount of water vapour decreases rapidly with altitude?
Answer:
The quantity of water vapour existing in the air depends upon the rate of evaporation and the temperature of the air which determines its holding capacity of water vapour. Both temperature and evaporation decreases with altitude and as a result water vapour also decreases rapidly with altitude.

Question 2(iv).
How are clouds formed? Classify them.
Answer:
Cloud is a mass of minute water droplets or tiny crystals of ice formed by the condensation of the water vapour in free air at considerable elevations. As the clouds are formed at some height over the surface of the earth, they take various shapes. According to their height, expanse, density and transparency or opaqueness clouds are grouped under four types :

• cirrus
• cumulus
• stratus
• nimbus.

3. Answer the following questions in about 150 words.

Question 3(i).
Discuss the salient features of the world distribution of precipitation.
Answer:
Salient features of the world distribution of precipitation are given below:

1. Different places on the earth’s surface receive different amounts of rainfall in a year and that too in different seasons. In general, as we proceed from the equator towards the poles, rainfall
goes on decreasing steadily. The coastal areas of the world receive greater amounts of rainfall than the interior of the continents. The rainfall is more over the oceans than on the landmasses of the world.

2. Between the latitudes 35° and 40° N and S of the equator, the rain is heavier on the eastern coasts and goes on decreasing towards the west. But, between 45° and 65° N and S of equator, the rainfall is first received on the western margins of the continents and it goes on decreasing towards the east.

3. In some regions rainfall is distributed evenly throughout the year such as in the equatorial belt and in the western parts of cool temperate regions. .

4. On the basis of the total amount of annual precipitation, major precipitation regimes of the world are identified as follows.

• The equatorial belt, the windward slopes of the mountains along the western coasts in the cool temperate zone and the coastal areas of the monsoon land receive heavy rainfall of over 200 cm per annum.
• Interior continental areas receive moderate rainfall varying from 100-200 cm per annum.
• The coastal areas of the continents receive moderate amount of rainfall.
• The central parts of the tropical land and the eastern and interior parts of the temperate lands receive rainfall varying between 50-100 cm per annum.
• Areas lying in the rain shadow zone of the interior of the continents and high latitudes receive very low rainfall-less than 50 cm per annum.

Question 3(ii).
What are forms of condensation? Describe the process of dew and frost formation.
Answer:
Condensation: The transformation of water vapour into water is called condensation. Condensation is caused by the loss of heat. When the water vapour or the moisture in the atmosphere takes one of the following forms — dew, frost, fog and clouds. Forms of condensation can be classified on the basis of temperature and location. Condensation takes place when the dew point is lower than the freezing point as well as higher than the freezing point.

• Dew: When the moisture is deposited in the form of water droplets on cooler surfaces of solid objects (rather than nuclei in air above the surface) such as stones, grass blades and plant leaves, it is known as dew.
• Frost: Frost forms on cold surfaces when condensation takes place below freezing point (CPC), i.e. the dew point is at or below the freezing point.
• Fog and Mist: When the temperature of an air mass containing a large quantity of water vapour falls all of a sudden, condensation takes place within itself on fine dust particles. So, the fog is a cloud with its base at or very near to the ground.
• Smog: Such a condition when fog is mixed with smoke, is described as smog.
• Clouds: Cloud is a mass of minute water droplets or tiny crystals of ice formed by the condensation of the water vapour in free air at considerable elevations. As the clouds are formed at some height over the surface of the earth, they take various shapes.

Class 11 Geography Chapter 11 NCERT Extra Questions

Class 11 Geography Chapter 11 Multiple Choice Questions

Question 1.
What do we say to the amount of water vapours present in atmosphere?
(a) Saturation
(b) Humidity
(c) Dew Points
(d) Dew.
Answer:
(b) Humidity

Question 2.
The temperature at which saturation occurs in a given sample of air is known as what?
(a) Saturation
(b) Humidity
(c) Dew Point
(d) Dew.
Answer:
(c) Dew point

Question 3.
Conversion of water vapours into water is called:
(a) Fog
(b) Condensation
(c) Dew
(d) Humidity.
Answer:
(b) Condensation

Question 4.
What do we call to a situation where fog with smoke is found?
(a) Fog
(b) Smog
(c) Dew
(d) Humidity.
Answer:
(b) Smog

Question 5.
What is the absolute amount of water vapours present in atmosphere called?
(a) Absolute humidity
(b) Relative humidity
(c) Condensation
(d) Fog.
Answer:
(a) Absolute humidity

Question 6.
At what height are cirrus clouds formed?
(a) 8000-12000 metres
(b) 3000-5000 metres
(c) 6000-9000 metres
(d) 4000-7000 metres.
Answer:
(a) 8000-12000 metres

Question 7.
At what height are cumulus clouds formed?
(а) 8000-12000 metres
(б) 3000-5000 metres
(c) 6000-9000 metres
(d) 4000-7000 metres.
Answer:
(d) 4000-7000 metres

Question 8.
When the saturated air mass comes across a mountain, it is forced to ascend and as it rises, it expands; the temperature falls, and the moisture is condensed. It is also known as what?
(a) Relief rain
(b) Cyclonic rain
(c) Hailstones
(d) Rainfall.
Answer:
(a) Relief rain

Question 9.
In atmosphere density of water vapour varies. To what per cent does it vary?
(a) 0 – 4%
(b) 5-10%
(c) 7-12%
(d) 9-15%.
Answer:
(a) 0-4%

Question 10.
The temperature at which the water starts evaporating is referred to as:
(a) Dew point
(b) The latent heat of vapourisation
(c) High temperature
(d) Condensation.
Answer:
(b) The latent heat of vapourisation

Question 11.
Interior continental areas receive:
(a) Heavy rainfall
(b) Moderate rainfall
(c) Low rainfall
(d) Cyclonic rainfall.
Answer:
(b) Moderate rainfall.

Class 11 Geography Chapter 11 Very Short Answer Type Questions

Question 1.
What is smog?
Answer:
Such a condition when fog is mixed with smoke, is described as smog.

Question 2.
How is humidity received in atmosphere?
Answer:
The moisture in the atmosphere is derived from water bodies through evaporation and from plants through transpiration.

Question 3.
What is relative humidity?
Answer:
The percentage of moisture present in the atmosphere as compared to its full capacity at a given temperature is known as the relative humidity.

Question 4.
What is absolute humidity?
Answer:
The actual amount of the water vapour present in the atmosphere is known as the absolute humidity. It is the weight of water vapour per unit volume of air and is expressed in terms of grams per cubic metre.

Question 5.
By what processes there a continuous exchange of water between the atmosphere, the oceans and the continents?
Answer:
There is a continuous exchange of water between the atmosphere, the oceans and the continents through the processes of evaporation, transpiration, condensation and precipitation.

Question 6.
How are clouds classified?
Answer:
According to their height, expanse, density and transparency or opaqueness clouds are grouped under four types :

1. cirrus;
2. cumulus;
3. stratus;
4. nimbus.

A combination of these four basic types can give rise to the following types of clouds: high clouds cirrus, cirrostratus, cirrocumulus; middle clouds—altostratus and altocumulus; low clouds—stratocumulus and nimbostratus and clouds with extensive vertical development cumulus and cumulonimbus.

Question 7.
When does condensation take place?
Answer:
The transformation of water vapour into water is called condensation. Condensation is caused by the loss of heat.

Question 8.
What are the suitable conditions for making of dew?
Answer:
The ideal conditions for its formation are clear sky, calm air, high relative humidity, and cold and long nights. For the formation of dew, it is necessary that the dew point is above the freezing point.

Question 9.
What are hailstones?
Answer:
Sometimes, drops of rain after being released by the clouds become solidified into small rounded solid pieces of ice and which reach the surface of the earth are called hailstones.

Question 10.
What is rain shadow area?
Answer:
The area situated on the leeward side, which gets less rainfall is known as the rain-shadow area.

Question 11.
What is precipitation?
Answer:
After the condensation of water vapour, the release of moisture is known as precipitation. This may take place in liquid or solid form.

Question 12.
What is convectional rain?
Answer:
Convectional Rain: The air on being heated, becomes light and rises up in convection currents. As it rises, it expands and loses heat and consequently, condensation takes place and cumulous clouds are formed. With thunder and lightening, heavy rainfall takes place but this does not last for long.

Question 13.
What factors influence the process of condensation?
Answer:
Condensation is influenced by the volume of air, temperature, pressure and humidity. Condensation takes place:

• when the temperature of the air is reduced to dew point with its volume remaining constant;
• when both the volume and the temperature are reduced;
• when moisture is added to the air through evaporation.

Class 11 Geography Chapter 11 Short Answer Type Questions

Question 1.
Name and define three important types of rainfall.
Answer:
On the basis of origin, rainfall may be classified into three main types:

1. The convectional rain
2. Orographic or relief rain and
3. Cyclonic or frontal rainfall

1. Convectional rain: The air on being heated, becomes light and rises up in convection currents. As it rises, it expands and loses heat and consequently, condensation takes place and cumulous clouds are formed. With thunder and lightening, heavy rainfall takes place but this does not last for long.
Such rain is common in the summer or in the hotter part of the day. It is very common in the equatorial regions and interior parts of the continents, particularly in the northern hemisphere.

2. Orographic rain: When the saturated air mass comes across a mountain, it is forced to ascend and as it rises, it expands; the temperature falls, and the moisture is condensed. In this sort of rain the windward slopes receive greater rainfall. After giving rain on the windward side, when these winds reach the other slope, they descend, and their temperature rises. Then their capacity to take in moisture increases and hence, these leeward slopes remain rainless and dry. The area situated on the leeward side, which gets less rainfall is known as the rain-shadow area. It is also known as the relief rain.

3. Cyclonic rainfall: These rains take place in low pressure areas where air moves from low pressure area to high pressure are a and this movement brings rainfall.

Question 2.
Explain the process of evaporation.
Answer:
Evaporation is a process by which water is transformed from liquid to gaseous state. Heat is the main cause for evaporation. The temperature at which the water starts evaporating is referred to as the latent heat of vapourisation. Increase in temperature increases water absorption and retention capacity of the given parcel of air. Similarly, if the moisture content is low, air has a potentiality of absorbing and retaining moisture. Movement of air replaces the saturated layer with the unsaturated layer. Hence, the greater the movement of air, the greater is the evaporation.

Question 3.
Explain cyclonic rain.
Answer:
Air expands when heated and gets compressed when cooled. This results in variations in the atmospheric pressure. The result is that it causes the movement of air from high pressure to low pressure, setting the air in motion. Air in horizontal motion is wind. Atmospheric pressure also determines when the air will rise or sink. The wind redistributes the heat and moisture across the planet, thereby, maintaining a constant temperature for the planet as a whole. The vertical rising of moist air cools it down to form the clouds and bring precipitation. It is called cyclonic rain.

Question 4.
Differentiate between
Answer:
(i) Precipitation and Condensation.

(ii) Absolute humidity and Relative humidity.

(iii) Convection rain and Relief rain.

(iv) Fog and Mist.

Class 11 Geography Chapter 11 Long Answer Type Questions

Question 1.
Explain about condensation in detail.
Answer:
1. Meaning: The transformation of water vapour into water is called condensation. Cause: Condensation is caused by the loss of heat.

2. Sublimation: When moist air is cooled, it may reach a level when its capacity to hold water vapour ceases. Then, the excess water vapour condenses into liquid form. If it directly condenses into solid form, it is known as sublimation.

3. Process: In free air, condensation results from cooling around very small particles termed as hygroscopic condensation nuclei. Particles of dust, smoke and salt from the ocean are particularly good nuclei because they absorb water. Condensation also takes place when the moist air comes in contact with some colder object and it may also take place when the temperature is close to the dew point. Condensation, therefore, depends upon the amount of cooling and the relative humidity of the air.

Factors affecting condensation:

• When the temperature of the air is reduced to dew point with its volume remaining constant;
• When both the volume and the temperature are reduced;
• When moisture is added to the air through evaporation.

However, the most favourable condition for condensation is the decrease in air temperature. After condensation the water vapour or the moisture in the atmosphere takes form of dew, frost, fog and clouds.

Question 2.
Explain about fog and mist.
Answer:
When the temperature of an air mass containing a large quantity of water vapour falls all of a sudden, condensation takes place within itself on fine dust particles. So, the fog is a cloud with its base at or very near to the ground.

• Because of the fog and mist, the visibility becomes poor to zero. In urban and industrial centres smoke provides plenty of nuclei which help in the formation of fog and mist.
• Such a condition when fog is mixed with smoke, is described as smog.
• The only difference between the mist and fog is that mist contains more moisture than the fog.
• In mist each nuceli contains a thicker layer of moisture. Mists are frequent over mountains as the warm air rises up the slopes and meets a cold surface.
• Fogs are drier than mist and they are prevalent where warm currents of air come in contact with cold currents. Fogs are mini clouds in which condensation takes place around nuclei provided by the dust, smoke, and the salt particles.

Class 11 Geography Chapter 11 HOTS Questions

Question 1.
On the basis of rainfall received, in how many groups can we classify the world?
Answer:
On the basis of rainfall received, we can classify the world into five groups.

1. The equatorial belt, the windward slopes of the mountains along the western coasts in the cool temperate zone and the coastal areas of the monsoon land receive heavy rainfall of over 200 cm per annum.
2. Interior continental areas receive moderate rainfall varying from 100 – 200 cm per annum.
3. The coastal areas of the continents receive moderate amount of rainfall.
4. The central parts of the tropical land and the eastern and interior parts of the temperate lands receive rainfall varying between 50-100 cm per annum.
5. Areas lying in the rain shadow zone of the interior of the continents and high latitudes receive very low rainfall-less than 50 cm per annum.

Question 2.
Use a diagram to explain the process of evaporation.
Answer:
Evaporation is a process by which water is transformed from liquid to gaseous state. Heat is the main cause for evaporation. Movement of air replaces the saturated layer with the unsaturated layer. Hence, the greater the movement of air, the greater is the evaporation.

Class 11 Geography

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Question 3(ii).
What type of vegetation would you find in the “C” and “A” type(s) of climate?
Answer:
Group A: Tropical Humid Climates Tropical humid climates exist between Tropic of Cancer and Tropic of Capricorn. The sun being overhead climate hot and humid. Annual range of temperature is very low and annual rainfall is high. The tropical group is divided into three types, namely:

1. Af- Tropical wet climate;
2. Am – Tropical monsoon climate;
3. Aw- Tropical wet and dry climate.

Group C: Warm temperate (mid-throughout the year and the presence of Inter Tropical Convergence Zone (ITCZ) make the
latitude) climates extend from 30° – 50° of latitude mainly on the eastern and western margins of continents. These climates generally have warm summers with mild winters. They are grouped into four types:

1. Humid subtropical, i.e. dry in winter and hot in summer (Cwa);
2. Mediterranean (Cs);
3. Humid subtropical, i.e. no dry season and mild winter (Cfa);
4. Marine west coast climate (Cfb).

Question 3(iii).
What do you understand by the term “Greenhouse Gases”? Make a list of greenhouse gases.
Answer:
The term greenhouse is derived from the analogy to a greenhouse used in cold areas for preserving heat. A greenhouse is made up of glass. The glass which is transparent to incoming short wave solar radiation is opaque to outgoing long wave radiation. The glass, therefore, allows in more radiation and prevents the long wave radiation going outside the glass house, causing the temperature inside the glasshouse structure warmer . than outside.
Greenhouse gases are those gases which cause global warming and result in rise in atmospheric temperature. These gases absorb long wave radiation. The processes that warm the atmosphere are often collectively referred to as the greenhouse effect.

Greenhouse Gases(GHGs): The primary GHGs of concern today are carbon dioxide (C02), Chlorofluorocarbons (CFCs), methane (CH4), nitrous oxide (N20) and ozone (03). Some other gases such as nitric oxide (NO) and carbon monoxide (CO) easily react with GHGs and affect their concentration in the atmosphere. The effectiveness of any given GHG molecule will depend on the magnitude of the increase in its concentration, its life time in the atmosphere and the wavelength of radiation that it absorbs.

PROJECT WORK

1. Collect information about Kyoto declaration related to global climate changes.
Answer:
Kyoto protocol is the most important protocol which was proclaimed in 1997. This protocol went into effect in 2005, ratified by 141 nations. Kyoto protocol bounds the 35 industrialised countries to reduce their emissions by the year 2012 to 5 percent less than the levels prevalent in the year 1990. The increasing trend in the concentration of GHGs in the atmosphere may, in the long run, warm up the earth. Once the global warming sets in, it will be difficult to reverse it. The effect of global warming may not be uniform everywhere. Nevertheless, the adverse effect due to global warming will adversely affect the life supporting system. Rise in the sea level due to melting of glaciers and ice-caps and thermal expansion of the sea may inundate large parts of the coastal area and islands, leading to social problems.

Class 11 Geography Chapter 12 NCERT Extra Questions

Class 11 Geography Chapter 12 Multiple Choice Questions

Question 1(i).
What kind of climate is expressed by the letter code- BSh?
(а) Tropical Dry
(b) Tropical Monsoon
(c) Subtropical Dry Steppe
(d) Mid Latitude Climate
Answer:
(c) Subtropical Dry Steppe

Question 1(ii).
What kind of climate is expressed by the letter code- ET?
(a) Humid subtropical
(b) Mediterranean
(c) Marine west coast
(d) Tundra
Answer:
(d) Tundra

Question 1(iii).
According to Koeppen, what is the average temperature of dry tropical climate?
(a) More than 20°C
(b) More than 18°C
(c) More than 40°C
(d) More than 10°C
Answer:
(b) More than 18°C

Question 1(iv).
During the 1930s, severe drought occurred in southwestern Great Plains of the United States.
What is it called?
(a) Famine area
(b) Barren area
(c) Dust bowl
(d) Dust flower
Answer:
(c) Dust bowl

Question 1(v).
Which of the following area come under tropical wet climate?
(a) Amazon Basin in South America
(b) Western equatorial Africa
(c) Islands of East Indies.
(d) All of the above
Answer:
(d) All of the above

Question 1(vi).
Which protocol was held for reducing the emission of GHGs into the atmosphere in 1997?
(a) Reid Jenero Earth Summit
(b) Johnsonburg meet
(c) Kyoto Protocol
(d) Copenhagen Meet
Answer:
(c) Kyoto Protocol

Question 1(vii).
In 8000 BC how was the climate of Rajasthan?
(a) Humid and cold
(b) Dry and warm
(c) Dry and cold
(d) Humid and warm
Answer:
(a) Humid and cold

Question 1(viii).
In the geological past, how was the earth’s climate about 500-300 million years ago, through the Cambrian, Ordovician and Silurian periods?
(a) Humid
(b) Warm
(c) Cold
(d) Dry
Answer:
(b) Warm

Question 1(ix).
Which of the following is not a greenhouse gas?
(a) Carbon dioxide
(b) Chlorofluorocarbons
(c) Methane
(d) Oxygen
Answer:
(d) Oxygen

Question 1(x).
What absorbs ultra-violet rays in stratosphere?
(a) Ozone
(b) Ions
(c) Methane
(d) Nitrogen
Answer:
(a) Ozone

Question 1(xi).
Europe witnessed what kind of experiences from 1550 to about 1850?
(а) Excess summer season
(b) Little Ice age
(c) Long dry age
(d) Long humid age
Answer:
(b) Little ice age

Question 1(xii).
What is thrown in atmosphere by volcanic eruptions?
(a) Aerosols
(b) Solid waste
(c) Alcohol
(d) Carbonmonoxide
Answer:
(a) Aerosols

Question 1(xiii).
Which type of climate exist in Plateau Station , Antarctica ,79°S according to Koeppen?
(a) Tundra climate
(b) Ice cap climate
(c) Taiga climate
(d) Cold climate with roots
Answer:
(b) Ice cap climate

Question 1(xiv).
The most important anthropogenic effect on the climate is the increasing trend in the concentration of greenhouse gases in the atmosphere. What can happen because of it?
(а) Global warming
(b) Air pollution
(c) Water pollution
(d) Land degradation
Answer:
(a) Global warming

Question 1(xv).
At which place the highest shade temperature of 58° C was recorded in Libya on 13 September 1922?
(a) Tripoli
(b) A1 Aziziyah
(c) Taiwan
(d) Tikari.
Answer:
(b) Al Aziziyah

Class 11 Geography Chapter 12 Very Short Answer Type Questions

Question 1.
In how many categories can we classify type- A climate according to Koeppen?
Answer:
The tropical group i.e. group- A is divided into three types, namely

1. Af- Tropical wet climate;
2. Am – Tropical monsoon climate;
3. Aw- Tropical wet and dry climate.

Question 2.
In how many groups has Koeppen classified the climate?
Answer:
Koeppen has classified climate into five groups: four are based on temperature and one is based on humidity. The capital letters: A, C, D and E delineate humid climates and B dry climates.

Question 3.
In which areas is tropical climate found? What are its features?
Answer:
Tropical humid climates exist between Tropic of Cancer and Tropic of Capricorn. The sun being overhead throughout the year and the presence of Inter Tropical Convergence Zone (ITCZ) make the climate hot and humid. Annual range of temperature is very low and annual rainfall is high.

Question 4.
What is the astronomical theory of Millankovitch oscillations?
Answer:
It is an astronomical theory of Millankovitch oscillations, which infer cycles in the variations in the earth’s orbital characteristics around the sun, the wobbling of the earth and the changes in the earth’s axial tilt. All these alter the amount of insolation received from the sun, which in turn, might have a bearing on the climate.

Question 5.
How does volcano affect the climate?
Answer:
Volcanic eruption throws up lots of aerosols into the atmosphere. These aerosols remain in the atmosphere for a considerable period of time reducing the sun’s radiation reaching the Earth’s surface. After the recent Pinatoba and El Cion volcanic eruptions, the average temperature of the earth fell to some extent for some years.

Question 6.
Explain about tundra climate.
Answer:
The tundra climate (ET) is so called after the types of vegetation, like low growing mosses, lichens and flowering plants. This is the region of permafrost where the sub soil is permanently frozen. The short growing season and water logging support only low growing plants. During summer, the tundra regions have very long duration of day light.

Question 7.
Explain about humid subtropical climate.
Answer:
Humid subtropical climate occurs poleward of Tropic of Cancer and Capricorn, mainly in North Indian plains and South China interior plains. The climate is similar to Aw climate except that the temperature in winter is warm.

Question 8.
What is Kyoto Protocol?
Answer:
International efforts have been initiated for reducing the emission of GHGs into the atmosphere. Kyoto protocol is the most important and was proclaimed in 1997. This protocol went into effect in 2005, ratified by 141 nations. Kyoto protocol bounds the 35 industrialised countries to reduce their emissions by the year 2012 to 5 per cent less than the levels prevalent in the year 1990.

Question 9.
In how many groups has warm temperate climates been divided?
Answer:
They are grouped into four types:

1. Humid subtropical, i.e. dry in winter and hot in summer (Cwa);
2. Mediterranean (Cs);
3. Humid subtropical, i.e. no dry season and mild winter (Cfa);
4.  Marine west coast climate (Cfb).

Class 11 Geography Chapter 12 Short Answer Type Questions

Question 1.
In which areas do we find tropical humid (Af) climate? What are its features?
Answer:
Tropical wet climate is found near the equator. The major areas are the Amazon Basin in South America, western equatorial Africa and the islands of East Indies.
Features:

• Significant amount of rainfall occurs in every month of the year as thunder showers in the afternoon.
• The temperature is uniformly high and the annual range of temperature is negligible.
• The maximum temperature on any day is around 30 C while the minimum temperature is around 20 C.
• Tropical evergreen forests with dense canopy cover and large biodiversity are found in this climate.

Question 2.
Explain about tropical wet and dry climate (Aw).
Answer:
Tropical Wet and Dry Climate (Aw): Tropical wet and dry climate occurs north and south of Af type climate regions. It borders with dry climate on the western part of the continent and Cf or Cw on the eastern part. Extensive Aw climate is found to the north and south of the Amazon forest in Brazil and adjoining parts.

Question 3.
Explain about Mediterranean Climate
Answer:
Mediterranean climate occurs around Mediterranean sea, along the west coast of continents in subtropical latitudes between 30 – 40 latitudes. Central California, Central Chile, along the coast in south eastern and south western Australia are examples of this type of climate. These areas come under the influence of subtropical high in summer and westerly wind in winter.
Features:

• The climate is characterised by hot, dry summer and mild, rainy winter.
• Monthly average temperature in summer is around 25 C and in winter below 10 C.
• The annual precipitation ranges between 35 – 90 cm.

Question 4.
Explain about humid sub tropical climate (Cfa).
Answer:
Humid subtropical climate lies on the eastern parts of the continent in subtropical latitudes. In this region the air masses are generally unstable and cause rainfall throughout the year.
They occur in eastern United States of America, southern and eastern China, southern Japan, northeastern Argentina, coastal south Africa and eastern coast of Australia.
Features:

• The annual average of precipitation vary from 75-150 cm.
• Thunderstorms in summer and frontal precipitation in winter are common.
• Mean monthly temperature in summer is around 27 C, and in winter it varies from 5 -12 C.
• The daily range of temperature is small.

Question 5.
In which areas do we find Marine west coast climate? Explain about the features of this climate?
Answer:
Marine west coast climate (Cfb) is located poleward from the Mediterranean climate on the west coast of the continents. The main areas are: North western Europe, west coast of North America, north of California, southern Chile, Southeastern Australia and New Zealand.
Features:

• Due to marine influence, the temperature is moderate and in winter, it is warmer than for its latitude.
• The mean temperature in summer months ranges from 15 -20 C and in winter 4 -10 C.
• The annual and daily ranges of temperature are small.
• Precipitation occurs throughout the year. Precipitation varies greatly from 50-250cm.

Class 11 Geography Chapter 12 Long Answer Type Questions

Question 1.
Explain the major climate categories by Koeppen.
Answer:
The first level recognises six major climatic types with each group being designated by a capital letter. These major climate categories have the following broad characteristics:

•  Tropical moist climates: These are very warm climates found in the tropics that experience high quantities of precipitation. The primary distinguishing characteristic of these climates is that all months have average temperatures above 18 C (64 F).
• Dry climates: These are climates that experience little precipitation during most of the year. Further, potential losses of water from evaporation and transpiration greatly exceed atmospheric input.
• Moist mid-latitude climates with mild winters: In these climates, summer temperatures are warm to hot and winters are mild. The primary distinguishing characteristic of these climates is that the coldest month has an average temperature between 18 C (64 F) and -3 C (27 F).
• Moist mid-latitude climates with cold winters: In these climates, summer temperatures are warm and winters are cold. The primary distinguishing characteristic of these climates is the average temperature of warmest month exceeds 10 C (50 F), and average temperature of coldest is below -3 C (27 F).
• Polar climates: These climates have very cold winters and summers, with no real summer season. The primary distinguishing characteristic of these climates is the warmest month has an average temperature below 10 C (50 F).
• Highland climates: These are climates that are strongly influenced by the effects of altitude. As a result, the climate of such locations is rather different from places with low elevations at similar latitudes.

Question 2.
Explain the climatic changes that has taken place since ancient times. Also explain its causes.
Answer:
The type of climate we experience now might be prevailing over the last 10,000 years with minor and occasionally wide fluctuations. The planet earth has witnessed many variations in climate since the beginning. Geological records show alteration of glacial and inter-glacial periods. The sediment deposits in glacial lakes also reveal the occurrence of warm and cold periods. The rings in the trees provide clues about wet and dry periods. Historical records describe the diversities in climate. All these evidences indicate that change in climate is a natural and continuous process. Archaeological findings show that the Rajasthan desert experienced wet and cool climate around 8,000 B.C. During the Pleistocene epoch, glacial and inter-glacial periods occurred, the last major peak glacial period was about 18,000 years ago. The present inter-glacial period started 10,000 years ago. Variability in climate occurs all the time. The nineties decade of the last century witnessed extreme weather events. The 1990s recorded the warmest temperature of the century and some of the worst floods around the world. Europe witnessed “Little Ice Age” from 1550 to about 1850. From about 1885¬1940 world temperature showed an upward trend. After 1940, the rate of increase in temperature slowed down.
Causes of Climate Change: The causes for climate change can be grouped into astronomical and terrestrial causes.

1. The astronomical causes: These are the changes in solar output associated with sunspot activities. Sunspots are dark and cooler patches on the sun which increase and decrease in a cyclical manner. According to some meteorologists, when the number of sunspots increase, cooler and wetter weather and greater storminess occur. A decrease in sunspot numbers is associated with warm and drier conditions.

2. Volcanism: It is considered as another cause for climate change. Volcanic eruption throws up lots of aerosols into the atmosphere. These aerosols remain in the atmosphere for a considerable period of time reducing the sun’s radiation reaching the Earth’s surface. After the recent Pinatoba and El Cion volcanic eruptions, the average temperature of the earth fell to some extent for some years.

3. Greenhouse gases: The most important anthropogenic effect on the climate is the increasing trend in the concentration of greenhouse gases in the atmosphere which is likely to cause global warming.

Question 3.
Explain about Polar climate (E).
Answer:
Polar Climates (E) exist poleward beyond 70 latitude. Polar climates consist of two types:

1. Tundra (ET);
2. Ice Cap (EF).

1. Tundra Climate (ET): The tundra climate (ET) is so called after the types of vegetation, like low growing mosses, lichens and flowering plants. This is the region of permafrost where the sub soil is permanently frozen. The short growing season and water logging support only low growing plants. During summer, the tundra regions have very long duration of day light.

2. Ice Cap Climate (EF): The ice cap climate (EF) occurs over interior Greenland and Antarctica. Even in summer, the temperature is below freezing point. This area receives very little precipitation. The snow and ice get accumulated and the mounting pressure causes the deformation of the ice sheets and they break. They move as icebergs that float in the Arctic and Antarctic waters. Plateau Station, Antarctica ,79 S, portray this climate.

Question 4.
Explain about Cold snow forest climates (D).
Answer:
Cold Snow Forest Climates (D) occur in the large continental area in the northern hemisphere between 40 -70 north latitudes in Europe, Asia and North America. Cold snow forest climates are divided into two types:

1. Df- cold climate with humid winter;
2. Dw- cold climate with dry winter.

The severity of winter is more pronounced in higher latitudes.
1. Cold climate with humid winters (Df): Cold climate with humid winter occurs poleward of marine west coast climate and mid latitude steppe. The winters are cold and snowy. The frost free season is short. The annual ranges of temperature are large. The weather changes are abrupt and short. Poleward, the winters are more severe.

2.Cold climate with dry winters (Dw): Cold climate with dry winter occurs mainly over Northeastern Asia. The development of pronounced winter anti cyclone and its weakening in summer sets in monsoon like reversal of wind in this region. Poleward summer temperatures are lower and winter temperatures are extremely low with many locations experiencing below freezing point temperatures for up to seven months in a year. Precipitation occurs in summer. The annual precipitation is low from 12-15 cm.

Question 5.
Write a detailed note on Tropical monsoon climate (Am).
Answer:
Tropical monsoon climate, occasionally also known as a tropical wet climate or tropical monsoon and trade-wind littoral climatein climate classification, is a relatively rare type of climate that corresponds to the Koppen climate classification category “Am”.

Tropical monsoon climates have monthly mean temperatures above 18 C in every month of the year and feature wet and dry seasons, as Tropical savanna climates do. Unlike tropical savanna climates however, a tropical monsoon climate’s driest month sees less than 60 mm of precipitation but more than (100 [total annual precipitation [mm}/25]). Also, a tropical monsoon climate tends to see less variance in temperatures during the course of the year than a tropical savanna climate. This climate has a driest month which nearly always occurs at or soon after the “winter” solstice for that side of the equator. Tropical monsoon climates are most commonly found in South and Central America. However, there are sections of South Asia, Southeastsia, Africa (particularly West and Central Africa), the Caribbean, and North America that also features this climate.

Class 11 Geography Chapter 12 Hots Questions

Question 1.
Explain about that region where there is no permanent settlements for human beings.
Ans:
Polar Climates (E) exist poleward beyond 70° latitude. There are no permanent human settlements. Only some scientists live there temporarily for their research and tasks related to manmade satellites.
Polar climates consist of two types:

1. Tundra (ET);
2. Ice Cap (EF).

1. Tundra Climate (ET): The tundra climate (ET) is so called after the types of vegetation, like low growing mosses, lichens and flowering plants. This is the region of permafrost where the sub soil is permanently frozen. The short growing season and water logging support only low growing plants. During summer, the tundra regions have very long duration of day light.
2. Ice Cap Climate (EF): The ice cap climate (EF) occurs over interior Greenland and Antarctica. Even in summer, the temperature is below freezing point. This area receives very little precipitation. The snow and ice get accumulated and the mounting pressure causes the deformation of the ice sheets and they break. They move as icebergs that float in the Arctic and Antarctic waters. Plateau Station, Antarctica, 79°S, portray this climate.

Question 2:
Give the letter codes used by Koeppen for following types of climates.

1. Tropical Wet
2. Sub tropical steppe
3. Humid Subtropical
4. Humid Continental
5. Polar Ice cap
6. Mid Latitude desert
7. Subarctic
8. Highlands with snow cover

Answer:

1. Af
2. BSh
3. Cfa
4. Df
5. EF
6. BWk
7. Dw
8. H.

Question 3:
Which letter code did Koeppen use for following temperature ranges?

1. Average temperature of the coldest month is 18° or higher.
2. Average temperature for all months is below 10° C.
3. Average temperature of the coldest month is -3° or lower.
4. Average temperature of the coldest month is higher than -3° but less than 18°.

Answer:

1. A – Tropical climates
2. E – Cold Climates
3. D – Cold Snow Forest Climates
4. C – Warm Climates.

Map Skill

Question 1.
Answer:

Class 11 Geography

The hydrological cycle, is the circulation of water within the earth’s hydrosphere in different forms i.e. the liquid, solid and the gaseous phases. About 71 percent of the planetary water is found in the oceans. The remaining is held as freshwater in glaciers and ice caps, groundwater sources, lakes, soil moisture, atmosphere, streams and within life. Nearly 59 percent of the water that falls on land returns to the atmosphere through evaporation from over the oceans as well as from other places. The remainder runs-off on the surface, infiltrates into the ground or a part of it becomes glacier.

Question 4.
Explain the components and process of hydrological cycle.
Answer:
Components of water cycle includes water storage in oceans, atmosphere, ice and snow, groundwater and water bodies. The processes of the water cycle vary in different components. In water stored in oceans evaporation, evapotranspiration and sublimation takes place. In water, in the atmosphere condensation and precipitation takes place. In water stored in ice and snow there is snowmelt runoff to streams. In surface runoff, there is stream flow freshwater storage and infiltration. In groundwater storage, groundwater discharge springs occurs.

Question 5.
Differentiate between continental shelf and continental slope.
Answer:
Continental shelf:

• It is an extended margin of each continent occupied by shallow sea, gulfs, etc. It is a submerge part of the land adjoining the coast.
• It is shallow and is about 800m deep with an average gradient 1° or even less.
• Its edges extended upto the denth of 150-200 m. ‘
• It contains the sediments deposited with land its average width is 80km.
• The largest continental shelf is a Siberian shelf in Arctic Ocean which stretches upto 1500 km of width.
• About one-fourth of the petroleum is produced from oil wells on the continental shelfs.
•  It is important for coastal transport and trade.

Continental slopes:

• It represents the edge of continental block.
• It connects continental shelf and ocean basin.
• The depth varies from 200-300 m.
• Its average gradient is 2-5°.
• It has a steep slope linking continental shelf and deep sea flow lying at an average depth of 3600 m.
• Canyons are formed here.

Question 6.
Write a short note on variation in salinity.
Answer:
The salinity for normal open ocean ranges between 33% and 37%. In the land locked Red Sea, it is as high as 41%, while in the estuaries and the Arctic, the salinity fluctuates from 0 – 35 %, seasonally. In hot and dry regions, where evaporation is high, the salinity sometimes reaches to 70%. Salinity decreases from 35% – 31% on the western parts of the northern hemisphere because of the influx of melted water from the Arctic region. In the same way, after 15° – 20° south, it decreases to 33%.

The average salinity of the Atlantic Ocean is around 36%. The highest salinity is recorded between 15° and 20° latitudes. Maximum salinity (37%) is observed between 20° N and 30° N and 20° W—60° W. It gradually decreases towards the north. The North Sea, in spite of its location in higher latitudes, records higher salinity due to more saline water brought by the North Atlantic Drift. Baltic Sea records low salinity due to influx of river water in large quantity. Highest salinity is found in water bodies as Lake Van in Turkey, Dead Sea, Great Salt Lake.

Class 11 Geography Chapter 13 Long Answer Type Questions

Question 1.
The average temperature of water on oceans floor keeps on falling from equator to poles systematically. Explain.
Answer:
The average temperature of surface water of the- oceans is about 27°C and it gradually decreases from the equator towards the poles. The rate of decrease of temperature with increasing latitude is generally 0.5°C per latitude. The average temperature is around 22°C at 20° latitudes, 14° C at 40° latitudes and 0° C near poles.

The oceans in the northern hemisphere record relatively higher temperature than in the southern hemisphere. The highest temperature is not recorded at the equator but slightly towards north of it.

The average annual temperatures for the northern and southern hemisphere are around 19° C and 16° C respectively. This variation is due to the unequal distribution of land and water in the northern and southern hemispheres.

Question 2.
Explain about horizontal distribution of salinity.
Answer:
Horizontal distribution of salinity:

• The salinity for normal Open Ocean ranges between 33% and 37%. In the land locked Red Sea records higher salinity due to high evaporation.
• Salinity is, however, very low in Black Sea due to enormous fresh water influx by rivers.
• The average salinity of the Indian Ocean is 35 %.
• The low salinity trend is observed in the Bay of Bengal due to influx of river water.
• On the contrary, the Arabian Sea shows higher salinity due to high evaporation and low influx of fresh water.

Question 3.
Explain about vertical distribution of salinity.
Answer:
Vertical distribution of salinity

• Salinity changes with depth, but the way it changes depends upon the location of the sea. Salinity at the surface increases by the loss of water to ice or evaporation, or decreased by the input of fresh waters, such as from the rivers.
• Salinity at depth is very much fixed, because there is no way that water is ‘lost’, or the salt is ‘added.’
• There is a marked difference in the salinity between the surface zones and the deep zones of the oceans. The lower salinity water rests above the higher salinity dense water.
• Salinity, generally, increases with depth and there is a distinct zone called the halocline, where salinity increases sharply.
• Other factors being constant, increasing salinity of seawater causes its density to increase. High salinity seawater, generally, sinks below the lower salinity water. This leads to stratification by salinity.

Question 4.
Explain about vertical distribution of temperature.
Answer:
The temperature structure of oceans over middle and low latitudes can be described as a three-layer system from surface to the bottom.

• The first layer represents the top layer of warm oceanic water and it is about 500 m thick with temperatures ranging between 20° and 25° C. This layer, within the tropical region, is present throughout the year but in mid-latitudes it develops only during summer.
• The second layer called the thermocline layer lies below the first layer and is characterised by rapid decrease in temperature with increasing depth. The thermocline is 500 – 1,000 m thick.
• The third layer is very cold and extends upto the deep ocean floor. In the Arctic and Antarctic circles, the surface water temperatures are close to 0 C and so the temperature change with the depth is very slight.

Question 5.
Explain the features of the deep sea plains, submarine ridges, ocean deeps and seamount.
Answer:
Abyssal plains (the deep sea plains):

• These are the world’s flattest and smoothest regions.
• About 40% of the oceanic floor is flat.
• It is formed accumulation of sediments on the sea floor.
• Its depth varies from 3000-6000 m.

Submarine ridges:

• Oceanic floors have submarine narrow and elongated ridges.
• They resemble mountain ridges on the earth surface.
• Peak of these ridges may rise above the sea level to form islands.
• Eg-Philippines Ice land is a mid-Atlantic ridge.

Oceanic deeps of submarine trenches:

• Deep narrow steep sided depression is found along the abyssal plain.
• The depth of these trenches may vary from 6,000 to 11,000 m. Example, Marina trenches is the deepest trench in Pacific Ocean.
• Trenches are formed as a result of tectonic forces and normally occur along the marines of Pacific Ocean.
• They occur at the base of the continental slopes and along the island area. Normally associated with volcanoes and strong earthquake.
• There are 32 trenches in Pacific Ocean, 19 in Atlantic Ocean and just 6 in Indian Ocean.

Seamount:

• It is the mount with a pointed submit rising from the sea floor but do not reach the surface of ocean. For example
  • Emperor seamount, an extension of Hawaiian islands in Pacific Ocean
  • The tallest seamount between Soman and New Zealand.
• Seamounts are volcanic in origin and can be 3000 to 4500 m tall.

Class 11 Geography Chapter 13 Hots Questions

Question 1.
“Ocean seems to be water body but it has many types of landforms within it”. Justify the statements by giving some examples.
Answer:
The statement is absolutely right. Like the surface of the earth ocean flow is neither level or flat, it is undulating and varying. It comprises of different types of landforms below it. Some of these are:

• Continental shelf: It is an extended margin of each continent occupied by shallow sea, gulfs, etc. It is a submerge part of the land adjoining the coast.
• Continental slopes: It represents the edge of continental block. It connects continental shelf and ocean basin. The depth varies from 200-300 m.
• Abyssal Plains (The Deep Sea Plains): These are the world’s flattest and smoothest regions. About 40% of the oceanic floor is flat. It is formed accumulation of sediments on the sea floor. Its depth varies from 3000-6000m.
• Sub Marine Ridges: Oceanic floors have sub-marine narrow and elongated ridges. They resemble mountain ridges on the earth surface. Peak of these ridges may rise above the sea level to form islands. Eg- Philippines Ice land is a mid-Atlantic ridge.
• Oceanic deeps of sub-marine trenches: Deep narrow steep sided depression found along the abyssal plain. The depth of these trenches may vary from 6,000 to 11,000 m. Example, Marina trenches is the deepest trench in Pacific Ocean.

Question 4.
Explain hydrological cycle.
Answer:
The hydrological cycle is a conceptual model that describes the storage and movement of water between the biosphere, atmosphere, lithosphere, and the hydrosphere. Water on our planet can be stored in any one of the
following major reservoirs: atmosphere, oceans, lakes, rivers, soils, glaciers, snowfields, and groundwater. Water moves from one reservoir to another by way of processes like evaporation, condensation, precipitation, deposi-tion, runoff, infiltration, subli¬mation, transpiration, melting, and groundwrater flow. The oceans supply most of the evaporated water found in the atmosphere. Of this evaporated water, only 91% of it is returned to the ocean basins by way of precipitation. The remaining 9% is transported to areas over landmasses where climatologically factors induce the formation of precipitation. The resulting imbalance between rates of evaporation and precipitation over land and ocean is corrected by runoff and groundwater flow to the oceans.

Map Skills

Question 1.
Show7 spatial distribution of surface temperature in degree celsius on a physical map of the world.
Answer:

Question 2.
Show on a physical map of the world, surface salinity of the different oceans.
Answer:

Question 3.
Show on a physical map of the world, mid oceanic ridges.
Answer:

Question 4.
Locate trenches on the map of the world.
Answer:

Question 5.
Show different types of ocean floors.
Answer:

Class 11 Geography

Class 11 Geography Chapter 14 Long Answer Type Questions

Question 1.
In how many categories can tides be classified on the basis of their height and frequency?
Answer:

• Semi-diurnal tide: It is the most common tidal pattern, featuring two high tides and two low tides each day. The successive high or low tides are approximately of the same height.
• Diurnal tide: There is only one high tide and one low tide during each day. The successive high and low tides are approximately of the same height.
• Mixed tide: Tides having variations in height are known as mixed tides. These tides generally occur along the west coast of North America and on many islands of the Pacific Ocean.
• Spring tides: The position of both the sun and the moon in relation to the earth has direct bearing on tide height. When the sun, the moon and the earth are in a straight line, the height of the tide will be higher. These are called spring tides.
• Neap tides: Wlien the sun and moon are at right angles to each other and the forces of the sun and moon tend to counteract one another. The moon’s attraction, though more than twice as strong as the sun’s, is diminished by the counteracting force of the sun’s gravitational pull. These are called neap tides.

Question 2.
White the characteristics of waves in the oceanic water.
Answer:
Characteristics of waves in the oceanic water are given below:

• The highest and lowest points of a wave are called the crest and trough.
• Wave height is the vertical distance from the bottom of a trough to the top of a crest of a wave.
• Wave amplitude is one-half of the wave height.
• Wave period is merely the time interval between two successive wave crests.
• Wavelength is the horizontal distance between two successive crests.
• Wave speed is the rate at which the wave moves through the water, and is measured in knots.
• Wave frequency is the number of waves passing a given point during a one- second time interval.

Question 3.
Explain how do heating of solar energy, wind, gravitation and coriolis force affect the ocean currents.
Answer:
Heating by solar energy: Heating by solar energy causes the water to expand, that is why, near the equator the ocean water is about 8 cm higher in level than in the middle latitudes. This causes a very slight gradient and water tends to flow down the slope.

• Wind: Wind blowing on the surface of the ocean pushes the water to move. Friction between the wind and the water surface affects the movement of the water body in its course.
• Gravity: Gravity tends to pull the water down the pile and create gradient variation.
• The Coriolis force: The coriolis intervenes and cause the water to move to the right in the northern hemisphere and to the left in the southern hemisphere.

Question 4.
Differentiate between warm currents and cold currents.
Answer:

Class 11 Geography Chapter 14 Hots Questions

Question 1.
Make a list of currents which are found in Pacific, Atlantic and Indian Ocean.
Answer:
This is a listing of the seventeen major surface ocean currents.

Question 2.
How is the movement of currents influenced by prevailing winds? Give examples.
Answer:
The prevailing winds, or winds that usually blow in the same direction, influence ocean currents because the wind causes friction on the water surface causing the water to move in the same direction as the wind. Some prevailing winds are called “trade winds” because merchants on sailboats used these regular winds to sail across the Indian Ocean or Atlantic Ocean to trade their goods. The wind made sailing to some places very easy and other places very difficult. Some of these regular winds change direction during certain months. This is called monsoon. Monsoon winds blow one direction from May to October, then change directions from November to April, which allowed the merchants to sail home in Monsoon areas of the world. The monsoon winds mainly effects South Asia (India). Indian traders sailed west to Africa in the summer and east back to India in the winter.

Question 3.
Why some currents are warm or cold?
Answer:
There are several warm ocean currents that move warm water away from the equator. These currents of water have warm air above the water. The warm air raises the temperature of the land it touches. These areas enjoy a much warmer climate than other places at the same latitude. Areas such as England would be much colder without the warm Gulf Stream. Warm ocean currents flow on the eastern side of a continents. They only reach the western side in high latitude areas. Another characteristic is that they flow away from the equator. Warm currents have higher temperatures, so they are less dense than cold water. Usually warm water has a higher salinity, but it remains less dense than cold water, so cold water is heavier and flows under warm water. The water is warmed on the surface, so warm currents flow across the surface of the ocean. As a warm current cools down, it drops down and becomes a cold water currents.

Question 4.
What are under currents?
Answer:
Under currents deep in the ocean flow in the opposite direction from the surface current above them. They replace the surface waters that are moving out. A major under current circles the globe at about 30 mph. The main under current is called the Great Conveyor Belt. It is truly like an underwater river. In fact, under currents are called “submarine rivers”.

Map Skill

Question 1.
Show on a world map the currents of the oceans.
Answer:

Class 11 Geography

Class 11 Geography Chapter 15 NCERT Textbook Questions Solved.

Multiple choice questions.

Question 1(i).
Which one of the following is included in biosphere?
(a) Only plants
(b) All living and non-living organisms
(c) Only animals
(d) All living organisms
Answer:
(b) All living and non-living

Question 1(ii).
Tropical grasslands are also known as:
(a) The prairies
(b) The savannas
(c) The steppes
(d) None of the above.
Answer:
(b) The savannas

Question 1(iii).
Oxygen combines with iron found in the rocks to form:
(a) Iron carbonate
(b) Iron nitrites
(c) Iron oxides
(d) Iron sulphate.
Answer:
(e) Iron oxides

Question 1(iv).
During photosynthesis, carbon dioxide combines with water in the presence of sunlight to form:
(a) Proteins
(b) Amino acids
(c) Carbohydrates
(d) Vitamins.
Answer:
(c) Carbohydrates.

2. Answer the following questions in about 30 words.

Question 2(i).
What do you understand by the term ‘ecology’?
Answer:
It is a scientific study of the interactions of organisms with their physical environment and with each other.

Question 2(ii).
What is an ecological system? Identify the major types of ecos_ stems in the world.
Answer:
The diversity of life-forms is maintained to bring a kind of balance. This balance is maintained in a particular proportion so that a healthy interaction between the biotic and the abiotic components goes on. The interactions of a particular group of organisms with abiotic factors within a particular habitat resulting in clearly defined energy flows and material cycles on land, water and air, are called ecological systems.

Ecosystems are of two major types: terrestrial and aquatic. Terrestrial ecosystem can be further be classified into ‘biomes’. Aquatic ecosystems can be classed as marine and freshwater ecosystems.

Question 2(iii).
What is food-chain? Give one example of a grazing food-chain identifying the various levels.
Answer:
The sequence of eating and being eaten and the resultant transfer of energy from one level to another is known as the food chain. There are two types of food chain, grazing food chain and detritus food chain.

1. In a grazing food chain, the first level starts with plants as producers and ends with carnivores as consumers at last level, with the herbivores being at the intermediate level. A capture initiated by grazing detritus food chain is based on autographs energy capture initiated by grazing animals and involves the decomposition or breaking down of organic wastes and death matter derived from the grazing food chain. For example plant- beetle- paddy stalk-frog-snake-hawk

2. A detritus food-chain is based on autotrophs energy capture initiated by grazing animals and involves the decomposition or breaking down of organic wastes and dead matter derived from the grazing food-chain.

Question 2(iv).
What do you understand by the term ‘food web’? Give examples.
Answer:
The interconnecting network of species is known as food web. A mouse feeding on grain may be eaten by different secondary consumers (carnivores) and these carnivores may be eaten by other different tertiary consumers (top carnivores). In such situations, each of the carnivores may consume more than one type of prey. As a result, the food- chains get interlocked with one another.

Question 2(v).
What is a biome?
Answer:
A biome is a plant and animal community that covers a large geographical area. The boundaries of different biomes on land are determined mainly by climate. Therefore, a biome can be defined as the total assemblage of plant and animal species interacting within specific conditions. These include rainfall, temperature, humidity and soil conditions. Some of the major biomes of the world are: forest, grassland, desert and tundra biomes.

3. Answer the following questions in about 150 words.

Question 3(i).
What are bio-geochemical cycles? Explain how nitrogen is fixed in the atmosphere.
Answer:
The sun is the source of all energy on earth. This energy initiates life processes in the biosphere through photosynthesis, the main source of food and energy for green plants. A very small fraction of about 0.1 percent of solar energy reaching earth is fixed in photosynthesis. More than half is used for plant respiration and the remaining part is temporarily stored or is shifted to other portions of the plant. During photosynthesis carbon dioxide is converted into organic compounds and oxygen.

The balance of the chemical elements is maintained by a cyclic passage through the tissues of plants and animals. The cycle starts by absorbing the chemical elements by the organism and is returned to the air, water and soil through decomposition. These cyclic movement of chemical elements of the biosphere between the organism and the environment are referred to as bio-geochemical cycles.

Fixing of nitrogen in the atmosphere Action of soil micro-organisms and associated plant roots on atmospheric nitrogen found in pore spaces of the soil comprise the principal source of free nitrogen. Lighting and cosmic radiation can also fix nitrogen in the atmosphere.

Question 3(ii).
What is an ecological balance? Discuss the important measures needed to prevent ecological imbalances.
Answer:
Ecological balance is a state of dynamic equilibrium within a community of organisms in a habitat or ecosystem. It can happen when the diversity of the living organisms remains relatively stable. Gradual changes do take place but that happens only through natural succession. It can also be explained as a stable balance in the numbers of each species in an ecosystem. This occurs through competition and cooperation between different organisms where population remains stable.

This balance is brought about by the fact that certain species compete with one another determined by the environment in which they grow. This balance is also attained by the fact that some species depend on others for their food and sustenance. Such accounts are encountered in vast grasslands where the herbivorous animals (deer, zebras, buffaloes, etc.) are found in plenty.

Ecological balance may be disturbed due to the introduction of new species, natural hazards or human causes. Human interference has affected the balance of plant communities leading to disturbances in the ecosystems. Such disturbances bring about numerous . secondary successions. Human pressure on the earth’s resources has put a heavy toll on the ecosystem. This has destroyed its originality and has caused adverse effects to the general environment. Ecological imbalances have brought many natural calamities like floods, landslides, diseases, erratic climatic occurrences, etc. There is a very close relationship between the plant and animal communities within particular habitats. Diversity of life in a particular area can be employed as an indicator of the habitat factor. Proper knowledge and understanding of such factors provide a strong base for protecting and conserving the ecosystems.

Class 11 Geography Chapter 15 NCERT Extra Questions

Class 11 Geography Chapter 15 Multiple Choice Questions

Question 1.
Which of the following is not a type of biome?
(a) Forest biome
(b) Desert biome
(c) Aquatic biome
(d) Sundri biome.
Answer:
(d) Sundri Biome

Question 2.
Very less rainfall and high rate of evaporation is a feature of which type of biome?
(a) Forest biome
(b) Desert biome
(c) Aquatic biome
(d) Sundri biome.
Answer:
(b) Desert biome

Question 3.
Which of the following is related to ecology?
(a) Birth of living organism
(b) Growth
(c) Development
(d) All of the above.
Answer:
(d) All of the above

Question 4.
All organisms become so much interlinked and interdependent on each other that the life of one cannot be imagined without the other. It is called:
(a) Biome
(b) Ecology
(c) Food chain
(d) Food web.
Answer:
(b) Ecology

Question 5.
Which of the following is included in biotic factors?
(a) Producers
(b) Consumers
(c) Decomposers
(d) All of the above.
Answer:
(d) All of the above

Question 6.
Ecosystems are of two types. These are:
(a) Terrestrial and aquatic ecosystem
(b) Biotic and abiotic ecosystem
(c) Regional and world ecosystem
(d) All of the above.
Answer:
(a) Terrestrial and aquatic ecosystem

Question 7.
Biome is a group of:
(a) Plants and animals
(b) Abiotic elements
(c) Aquatic elements
(d) None of the above.
Answer:
(a) Plants and animals

Question 8.
Which of the following is included in primary consumers?
(a) Carnivores
(b) Herbivores
(c) Decomposers
(d) All of the above.
Answer:
(a) Carnivores

Question 9.
Which of the following is included in secondary consumers?
(a) Carnivores
(b) Herbivores
(c) Decomposers
(d) All of the above.
Answer:
(b) Herbivores

Question 10.
A very small portion of the sunlight received on the earth is used in photosynthesis. What percent is it?
(a) Only 0.50 percent
(b) Only 1 percent
(c) Only 0.1 percent
(d) Only 0.2 percent.
Answer:
(c) Only 0.1 percent.

Class 11 Geography Chapter 15 Very Short Answer Type Questions

Question 1.
Name important biomes of the world.
Answer:
A biome is a plant and animal community that covers at large geographical area. Abiome can be defined as the total assemblage of plant and animal species interacting within specific conditions. These include rainfall, temperature, humidity and soil conditions. Some of the major biomes of the world are forest, grassland, desert and tundra biomes.

Question 2.
Who are primary and secondary consumers?
Answer:
The primary consumers include herbivorous animals like deer, goats,
mice and all plant-eating animals. The carnivores include all the flesh-eating animals like snakes, tigers and lions. Certain carnivores that feed also on carnivores are known as top carnivores like hawks and mongooses.

Question 3.
On whom do primary, secondary and tertiary producers depend?
Answer:
Primary consumers depend on producers who make the food themselves. Secondary consumers depend on primary consumers and tertiary consumers in turn depend on secondary consumers.

Question 4.
Give meaning of food chain with examples.
Answer:
The sequence of eating and being eaten and the resultant transfer of energy from one level to another is known as food chain. There are two types of food chain: grazing food chain and detritus food chain. For example plant- beetle- paddy stalk-frog-snake-hawk.

Question 5.
What kind of changes take place during photosynthesis?
Answer:
During photosynthesis, carbon dioxide is converted into organic compounds and oxygen. Out of the total solar insolation that reaches the earth’s surface, only a very small fraction (0.1 percent) is fixed in photosynthesis. More than half is used for plant respiration and the remaining part is temporarily stored or is shifted to other portions of the plant.

Question 6.
What is water cycle?
Answer:
All living organisms, the atmosphere and the lithosphere maintain between them a circulation of water in solid, liquid or gaseous form referred to as the water or hydrologic cycle.