11 March, 2015

Class VII: Summative Assessment - II (Geography) Answer Key

 

Multiple choice questions:

Q1. Which one of the following is not a determining factor of vegetation (1)
(a) Temperature (b) Rainfall (c) Sunlight (d) Development
Ans: (d) Development

Q2. Earliest settlements grew around (1)
(a) River Banks (b) Forest Areas (c) Plains (d) Foot Hills
Ans: (a) River Banks

Q3. The amount of fresh water present on the earth is (1)
(a) 3% (b) 1% (c) 29% (d) 8%
Ans: (a) 3%

 

Very short answer questions:

Q4. What is normal lapse rate? (1)
Ans: Temperature decreases at the rate of 1 degree Celsius from every 165 mtrs of ascent. This decline is known as normal lapse rate.

Q5. What does the word 'Tsunami' means? (1)
Ans: Tsunami is a Japanese word that means "Harbour waves" as the harbours get destroyed whenever there is tsunami. The term "Tsunami" has been derived from: - "Tsu" – Harbour and "Nami" – Waves. Meaning huge tidal waves.

 

Short answer questions:

Q6. Distinguish between: Tropical and Temperate Grasslands (2)
Ans: (Any two points)

Q7. Distinguish between: Rural and Urban Settlement. (2)
Ans: (Any two points)

Q8. Distinguish between: Spring Tides and Neap Tides. (2)
Ans: (Any two points)

 

Medium answer questions:

Q9. Define the term Communication What are its two categories? What is their importance? (3)
Ans: Communication is the process of conveying messages (sending or receiving) and ideas to others. With the development of technology humans have devised new and fast modes of communication.
The two categories of communication are:
(a) Personal Communication: Postal and telegraph services, telephones, e-mails, etc are personal means of communication.
(b) Mass Communication: Through Newspapers, magazines, radio, television, films, etc. Communication can be done with large no. Of people. This is known as Mass Communication.

With the help of these two means of communications life has become very fast and comfortable. With just one click we can share information throughout the world and also by just sitting at home itself we come to know what is happening in the world. The means of communications have made the world a large global society.

Q10. Explain the three movements of ocean water? (3)
Ans: Waves, Tides and Ocean Currents are the three movements of ocean water.
WAVES
• When the water on the surface of the ocean rises and falls alternately, they are called waves.
• During a storm, the winds blowing at very high speed form huge waves. These may cause tremendous destruction.
• An earthquake, a volcanic eruption or underwater landslides can shift large amounts of ocean water. As a result a huge tidal wave called tsunami originates.
• Tsunami is a Japanese word that means "Harbour waves" as the harbours get destroyed whenever there is tsunami. The term "Tsunami" has been derived from: - "Tsu" – Harbour and "Nami" – Waves. Meaning huge tidal waves.

TIDES
• The rhythmic rise and fall of ocean water twice in a day is called a tide.
• It is high tide when water covers much of the shore by rising to its highest level.
• It is low tide when water falls to its lowest level and recedes from the shore.
• During the full moon and new moon days, the sun, the moon and the earth are in the same line and the tides are highest. These tides are called spring tides.
• But when the moon is in its first and last quarter, the ocean waters get drawn in diagonally opposite directions by the gravitational pull of sun and earth resulting in low tides. These tides are called neap tides.
• High tides help in navigation. This helps the ships to arrive at the harbour more easily.
• The high tides also help in fishing. Also, the rise and fall of water due to tides is being used to generate electricity in some places.

OCEAN CURRENTS
• The horizontal movement of ocean water in the form of streams flowing constantly in definite directions is known as Ocean Currents.
• Factors affecting the Ocean Currents: -
(a) Planetary Winds.
(b) Rotation of the Earth
(c) Variation in the temperature
(d) Density of ocean water
(e) Shapes of the coastlines
• The ocean currents may be warm or cold.
• The warm ocean currents originate near the equator and move towards the poles.
• The cold currents carry water from polar or higher latitudes to tropical or lower latitudes.
• The ocean current influence the temperature conditions of the area.
• The place where warm and cold currents meet, dens fog is produced, reducing the visibility and thus, making it difficult for navigation. But at the same time these are the best fishing grounds of the world.
• The general circulation of ocean currents is clockwise in the Northern Hemisphere and anti-clockwise in the Southern Hemisphere.

Q11. Name the different means of transportation. Explain any two means of transportation (3)
Ans: Different means of transportation are Roadways, Waterways, Railways, Airways. Explain any two.
ROADWAYS
• The most commonly used means of transport are the roads. Especially, for short distances. Roads can be metalled (Pucca) and unmetalled (Kutcha).
• Roads are the best means to link the rural and urban places across the country.
• In developed countries road network is very good.
• The plains have a dense network of roads because it is easy to construct roads in plain than in the mountains.
• In India we have National Highways connecting all major cities of the country. There are state highways and district roads which connects all cities and towns.
• Manali-Leh highway in the Himalayan Mountains is one of the highest roadways in the world.

RAILWAYS
• Railways is the fastest and the cheapest means of land transportation .
• Diesel and electric engines have largely replaced the steam engines.
• Electric engines are fast and eco-friendly and don't cause pollution.
• Factors responsible for the construction of railway lines: - Relief Features, Climatic Conditions, Density of Population and availability of resources.
• Railway network is more developed in the plains than in the mountiains.
• Indian railway network is well developed. It is the largest in Asia.

WATERWAYS
• Waterways are the oldest and the cheapest means of transportation to carry heavy and bulky goods from one country to another.
• Waterways are mainly of two types – inland waterways and sea routes.
• Inland Waterways: Navigable rivers and lakes are used as inland waterways. Some of the important inland waterways are the Ganga-Brahmaputra river system, the Great Lakes in North America and the river Nile in Africa.
• Sea routes and oceanic routes are mostly used for transporting merchandise and goods from one country to another. These routes are connected with the ports. Some of the important ports of the world are Singapore and Mumbai in Asia, New York, Los Angeles in North America, Rio de Janerio in South America, Durban and Cape Town in Africa, Sydney in Australia, London and Rotterdam in Europe.
• Important Sea Routes of the world: North Atlantic Route which connects North America with Europe. Mediterranean Sea – Indian Ocean connecting Europe-East Africa-South Asia-Cape of Good Hope-Australia
• Major sea ports of India: - Mumbai, Kandla, Kochi, Chennai, Vishakhapatnam, Kolkata.

AIRWAYS
• This is the fastest & most comfortable means of transportation and also the most expensive due to high cost of fuels.
• Air traffic is adversely affected by bad weather like fog and storms, etc.
• It is the only mode of transport to reach the most remote and distant areas especially where there are no roads and railways.
• Helicopters are extremely useful in most inaccessible areas and in time of calamities for rescuing people and distributing food, water, clothes and medicines.
• Some of the important airports are Delhi, Mumbai, New York, London, Paris, Frankfurt and Cairo.
• Air Services are of two types:
(1) Domestic Airways: Fly within the boundaries of a country.
(2) International Airways: Fly abroad and connects major cities of the world.

 

Long answer questions:

Q12. With a suitable diagram explain the structure of the atmosphere. (5)
Ans. Structure of Atmosphere: Atmosphere is divided into five different layers (Troposphere, Stratosphere, Mesosphere, Ionosphere and Exosphere). It extends upto 500 kms.

1. Troposphere:
• This layer is next to earth surface. It Extends upto 15 kms from the earth's surface.
• Temperature decreases at the rate of 1 degree Celsius from every 165 mtrs of ascent. This decline is known as normal lapse rate.
• Average height: 13 kms at poles and 18 kms over the equator.
• All weather changes take place in this layer. Oxygen exists in this layer.
• The boundary separating troposphere and stratosphere is known as tropopause.

2. Stratosphere:
• This layer is next to troposphere and it extends from 15 kms to 50 kms.
• This layer is free from weather changes, cloud formation and dust particles. Hence, this layer is ideal for the air transportation.
• Ozone layer is present here. Ozone layer absorbs/reflects the harmful ultraviolet rays of the sun.
• The boundary separating stratosphere and mesosphere is known as stratopause.

3. Mesosphere:
• This layer is next to stratosphere and it extends from 50 kms to 80 kms.
• Temperature again drops in this layer and can reach upto -100 degree Celsius at the upper boundary layer.
• The boundary separating mesosphere and ionosphere is known as mesopause.

4. Thermosphere:
• This layer is next to mesosphere and it extends from 80 kms to 400 kms.
• This layer contains electrically charged particles called ions, which are found at a height of 250 kms. Due to presence of these ions, this layer is also known as ionosphere.
• This layer protects us from the harmful radiation. Temperature increase with increase in height.

5. Exosphere:
• This is the uppermost layer above the ionosphere and it extends from 400 kms onwards and there is no end. It is a very thin layer and it merges with the space.
• This layer protects us from the harmful radiation.
• Temperature is very high. Light gases like hydrogen and helium float into space from here.

Q13. What do you mean by natural vegetations? How natural vegetation of the world has been classified? Describe the characteristics of forests (any three). (5)
Ans: Plants which grow naturally without any human interference, covering a large area is known as natural vegetation.
Natural vegetation of the world has been classified into three types: Forest, Grasslands and Desert Shrubs.
Characteristics of the forests (any three).

Tropical Rainforests:
These forests are also called Tropical Evergreen.

Location:
• Forests found near the Equator (10° North to 10° South) in Amazon & Zaire Basin and Southeast Asia.
Climate:
• These regions are hot and receive heavy rainfall throughout the year.
Characteristics:
• As there is no particular dry season, the trees do not shed their leaves altogether. This is the reason they are called evergreen.
• Maximum varieties of trees are found. Trees are tall with large trunks.
• The thick canopies of the closely spaced trees do not allow the sunlight to penetrate inside the forest even in the day time. Thus, grass is not found in these forests.
• Hardwood trees like rosewood, teak, sal, ebony, and mahogany are the common trees found here.
• Here the population found is very less. Due to dense forests commercial exploitation of these forests has not be possible, making them economically backward.
Wildlife:
• Large variety and most colourful animals are found here.
• Monkey, Ape, Birds, Hippopotamus, snake, python, Frog, Crocodile, etc. Anaconda, world's largest snake is also found in these areas.

Tropical Deciduous Forests:
These forests are also called Monsoon Forests.

Location:
• Forests found in large part of India, Northern Australia and in Central America.
Climate:
• These regions are warm and receive rainfall less than 200 cms.
Characteristics:
• These regions experience seasonal changes. Trees shed their leaves in the dry season to conserve water.
• Trees like sandalwood, teak, sal, ebony, bamboo, etc. are the common trees found here.
• Forests are not very dense thus; commercial exploitation of these forests is possible.
Wildlife:
• Tigers, lions, elephants, langoors and monkeys are the common animals of these regions.

Temperate Evergreen Forests:
These forests are also called Mixed Forests.
Location:
• Forests found in South-eastern parts of USA, Australia, Brazil and China.
Climate:
• These regions have cool winters and receive rainfall throughout the year.

Characteristics:
• They comprise both hard and soft wood trees like oak, pine, eucalyptus, etc.
• They look like Tropical Forest in thickness and variety.
• Timber (wood) from these forests is used for commercial purpose.
Wildlife:
• Deer, Wolves, Bears, Wild Boar, Foxes, Squirrels, Badgers, Skunks, Owls, Finches, etc. are the common animals of these regions.

Temperate Deciduous Forests:
These forests are also called Monsoon Forests.

Location:
• As we go towards higher latitudes, there are more temperate deciduous forests. These are found in the north eastern part of USA, China, Japan, New Zealand, etc.
Climate:
• These regions have cool winters and receive moderate rainfall.
Characteristics:
• Trees shed their leaves in autumn season and remain leafless through winters.
• The common trees are oak, ash, beech, etc.
• Forests are not very dense thus; commercial exploitation of these forests is possible.
Wildlife:
• Deer, foxes, wolves are the animals commonly found. Birds like pheasants, monals are also found here.

Mediterranean Forests:

Location:
• Found in areas around Mediterranean Sea, Central Chile, South-West USA, Australia, Africa.
Climate:
• These regions have hot & dry summers and mild & wet winters.
Characteristics:
• Mediterranean trees adapt themselves to dry summers with the help of their thick barks and wax coated leaves which help them reduce transpiration. Also, here the plants have long tap roots to reach underground water, called "Xerophytic Plants".
• Mediterranean regions are known as 'Orchards of the world' for their fruit cultivation.
• Citrus fruits such as oranges, figs, olives and grapes are commonly cultivated here because people have removed the natural vegetation in order to cultivate what they want to.
Wildlife:
• There isn't much wildlife here.

Coniferous Forests:
These forests are also called "Taiga Forest".

Location:
• Found in the higher latitudes (50° – 70°) of Northern hemisphere.
Climate:
• These regions have cool & short summers and cold & long winters. These forests are also seen in the higher altitudes. Norway, Sweden, Finland, Russia and Canada.
Characteristics:
• Forests consist of tall, softwood evergreen trees.
• Limited species of trees are found. These trees are evergreen and grow apart from each other.
• Trees are conical shaped with needle shaped leaves and trees are found in large groups.
• Chir, pine, cedar are the important variety of trees in these forests. Lumbering is the common activity. Soft wood is used for manufacturing paper.
Wildlife:
Fur-bearing animals like Silver fox, mink, and polar bear are the common animals found here.

 

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Comments

devil 28 December, 2017Very good
Vishal Kumar03 November, 2018Wow, thanks

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