Selina Textbook Solutions: Major Water Bodies | Geography Class 6 ICSE PDF Download

 Page 1


POINTS TO REMEMBER 
? Nearly 71 per cent of the surface of earth is covered by water. 
? There are five large water bodies called oceans in the world. These are the Pacific 
Ocean, the Atlantic Ocean, the Indian Ocean, the Arctic Ocean and the Southern 
Ocean. Smaller water bodies include seas, lakes and rivers. 
? A river is a stream of water which flows in a channel from high ground to low 
ground and finally to a lake or a sea. The place where the river originates is called 
its source and the place where it ends is called its mouth. 
? The route or course of a river has three stages—the upper, middle and lower 
stages. In the upper stage the river is in the mountains, in the middle stage it flows 
over plains, and in the lower stage the river generally meets an ocean or a sea. 
? Almost all human activities generate waste which causes pollution. 
? Untreated liquid waste from kitchens and toilets of households, liquid wastes from 
thermal power plants, surface run-off from farms and oil spills are the main causes 
of water pollution. 
? Water pollution causes diseases such as typhoid, cholera and amoebic dysentery. 
IMPORTANT TERMS 
Ridge : A high pointed area near the top of a mountain. 
Surface run-off : Water from rain, melting snow, or other sources that flows over land 
and is a part of the water cycle. 
THINK AND ANSWER 
Everything that we do creates waste, which, in turn, creates pollution. How do you think 
you can reduce the amount of waste you generate? 
Answer: 
1. Liquid waste from thermal power plants should not be discharged in the rivers. As 
It increases the dissolved oxygen content of river water, leading to a sudden rise 
in microbe population. This, in turn, reduces the level of oxygen in the river and 
makes it difficult for other kinds of organisms to survive. 
2. Surface run-off should not be discharged in the rivers as 
Surface run-off from farms carries organic and inorganic fertilizers into water 
bodies. This promotes the growth of algae, which reduces the dissolved oxygen 
level in water. Other living organisms in water bodies, including fish, cannot 
survive in such conditions. 
3. By not discharging the Untreated liquid waste into the rivers. Untreated liquid 
waste from kitchens and toilets is often discharged into rivers. This exposes 
people who use river water to diseases such as typhoid, cholera and amoebic 
dysentery. 
Page 2


POINTS TO REMEMBER 
? Nearly 71 per cent of the surface of earth is covered by water. 
? There are five large water bodies called oceans in the world. These are the Pacific 
Ocean, the Atlantic Ocean, the Indian Ocean, the Arctic Ocean and the Southern 
Ocean. Smaller water bodies include seas, lakes and rivers. 
? A river is a stream of water which flows in a channel from high ground to low 
ground and finally to a lake or a sea. The place where the river originates is called 
its source and the place where it ends is called its mouth. 
? The route or course of a river has three stages—the upper, middle and lower 
stages. In the upper stage the river is in the mountains, in the middle stage it flows 
over plains, and in the lower stage the river generally meets an ocean or a sea. 
? Almost all human activities generate waste which causes pollution. 
? Untreated liquid waste from kitchens and toilets of households, liquid wastes from 
thermal power plants, surface run-off from farms and oil spills are the main causes 
of water pollution. 
? Water pollution causes diseases such as typhoid, cholera and amoebic dysentery. 
IMPORTANT TERMS 
Ridge : A high pointed area near the top of a mountain. 
Surface run-off : Water from rain, melting snow, or other sources that flows over land 
and is a part of the water cycle. 
THINK AND ANSWER 
Everything that we do creates waste, which, in turn, creates pollution. How do you think 
you can reduce the amount of waste you generate? 
Answer: 
1. Liquid waste from thermal power plants should not be discharged in the rivers. As 
It increases the dissolved oxygen content of river water, leading to a sudden rise 
in microbe population. This, in turn, reduces the level of oxygen in the river and 
makes it difficult for other kinds of organisms to survive. 
2. Surface run-off should not be discharged in the rivers as 
Surface run-off from farms carries organic and inorganic fertilizers into water 
bodies. This promotes the growth of algae, which reduces the dissolved oxygen 
level in water. Other living organisms in water bodies, including fish, cannot 
survive in such conditions. 
3. By not discharging the Untreated liquid waste into the rivers. Untreated liquid 
waste from kitchens and toilets is often discharged into rivers. This exposes 
people who use river water to diseases such as typhoid, cholera and amoebic 
dysentery. 
4. By taking dual care of leakage of Oil Spills in rivers. An oil spill occurs when crude 
oil, while being transported from one country to another, gets leaked into the sea. 
VALUES AND LIFE SKILLS 
Water is very important for sustaining life on earth. We should be careful while using 
water and should take steps to save our water resources. 
What are the things that you can do to save water? 
Answer: 
We can save water by doing following things, 
1. Check all faucets, pipes and toilets for leaks. 
2. Install water saving showerheads and ultra-low-flush toilets. 
3. Take shorter showers. 
4. Never use your toilet as a wastebasket. 
5. Turn off the water while brushing your teeth or shaving. 
EXERCISES 
A. Match the columns 
 
Answer: 
 
 
B. With the help of your atlas identify and mark the following in an outline map of 
the world. 
Question 1. 
The largest ocean in the world 
Page 3


POINTS TO REMEMBER 
? Nearly 71 per cent of the surface of earth is covered by water. 
? There are five large water bodies called oceans in the world. These are the Pacific 
Ocean, the Atlantic Ocean, the Indian Ocean, the Arctic Ocean and the Southern 
Ocean. Smaller water bodies include seas, lakes and rivers. 
? A river is a stream of water which flows in a channel from high ground to low 
ground and finally to a lake or a sea. The place where the river originates is called 
its source and the place where it ends is called its mouth. 
? The route or course of a river has three stages—the upper, middle and lower 
stages. In the upper stage the river is in the mountains, in the middle stage it flows 
over plains, and in the lower stage the river generally meets an ocean or a sea. 
? Almost all human activities generate waste which causes pollution. 
? Untreated liquid waste from kitchens and toilets of households, liquid wastes from 
thermal power plants, surface run-off from farms and oil spills are the main causes 
of water pollution. 
? Water pollution causes diseases such as typhoid, cholera and amoebic dysentery. 
IMPORTANT TERMS 
Ridge : A high pointed area near the top of a mountain. 
Surface run-off : Water from rain, melting snow, or other sources that flows over land 
and is a part of the water cycle. 
THINK AND ANSWER 
Everything that we do creates waste, which, in turn, creates pollution. How do you think 
you can reduce the amount of waste you generate? 
Answer: 
1. Liquid waste from thermal power plants should not be discharged in the rivers. As 
It increases the dissolved oxygen content of river water, leading to a sudden rise 
in microbe population. This, in turn, reduces the level of oxygen in the river and 
makes it difficult for other kinds of organisms to survive. 
2. Surface run-off should not be discharged in the rivers as 
Surface run-off from farms carries organic and inorganic fertilizers into water 
bodies. This promotes the growth of algae, which reduces the dissolved oxygen 
level in water. Other living organisms in water bodies, including fish, cannot 
survive in such conditions. 
3. By not discharging the Untreated liquid waste into the rivers. Untreated liquid 
waste from kitchens and toilets is often discharged into rivers. This exposes 
people who use river water to diseases such as typhoid, cholera and amoebic 
dysentery. 
4. By taking dual care of leakage of Oil Spills in rivers. An oil spill occurs when crude 
oil, while being transported from one country to another, gets leaked into the sea. 
VALUES AND LIFE SKILLS 
Water is very important for sustaining life on earth. We should be careful while using 
water and should take steps to save our water resources. 
What are the things that you can do to save water? 
Answer: 
We can save water by doing following things, 
1. Check all faucets, pipes and toilets for leaks. 
2. Install water saving showerheads and ultra-low-flush toilets. 
3. Take shorter showers. 
4. Never use your toilet as a wastebasket. 
5. Turn off the water while brushing your teeth or shaving. 
EXERCISES 
A. Match the columns 
 
Answer: 
 
 
B. With the help of your atlas identify and mark the following in an outline map of 
the world. 
Question 1. 
The largest ocean in the world 
Answer: 
Pacific ocean. 
Question 2. 
The northernmost ocean 
Answer: 
Arctic ocean. 
Question 3. 
An inland sea in Eurasia 
Answer: 
Aral sea. 
Question 4. 
Two rivers in Europe 
Answer: 
Rhine and Danube. 
c. Answer the following questions in brief 
Question 1. 
Name the major water bodies on earth. 
Answer: 
The major water bodies on earth are oceans, seas, lakes and rivers. 
Question 2. 
What is the Ring of Fire? 
Answer: 
The pacific ocean is bordered by volcanic mountains on its edges. So it is termed as 
‘Ring of Fire’. 
Question 3. 
What is the difference between a gulf and a bay? 
Answer: 
A gulf is an inlet of the sea of large areal proportions while a bay is an open, curving 
indentation made by the sea or a lake into a coastline. Gulfs are more indented than 
bays and also more enclosed. 
Question 4. 
What do you understand by strait? Give an example. 
Answer: 
A strait is a narrow stretch of water that joins two large water bodies. The Strait of 
Gibraltar, for example, connects the Mediterranean Sea to the North Atlantic Ocean. 
Page 4


POINTS TO REMEMBER 
? Nearly 71 per cent of the surface of earth is covered by water. 
? There are five large water bodies called oceans in the world. These are the Pacific 
Ocean, the Atlantic Ocean, the Indian Ocean, the Arctic Ocean and the Southern 
Ocean. Smaller water bodies include seas, lakes and rivers. 
? A river is a stream of water which flows in a channel from high ground to low 
ground and finally to a lake or a sea. The place where the river originates is called 
its source and the place where it ends is called its mouth. 
? The route or course of a river has three stages—the upper, middle and lower 
stages. In the upper stage the river is in the mountains, in the middle stage it flows 
over plains, and in the lower stage the river generally meets an ocean or a sea. 
? Almost all human activities generate waste which causes pollution. 
? Untreated liquid waste from kitchens and toilets of households, liquid wastes from 
thermal power plants, surface run-off from farms and oil spills are the main causes 
of water pollution. 
? Water pollution causes diseases such as typhoid, cholera and amoebic dysentery. 
IMPORTANT TERMS 
Ridge : A high pointed area near the top of a mountain. 
Surface run-off : Water from rain, melting snow, or other sources that flows over land 
and is a part of the water cycle. 
THINK AND ANSWER 
Everything that we do creates waste, which, in turn, creates pollution. How do you think 
you can reduce the amount of waste you generate? 
Answer: 
1. Liquid waste from thermal power plants should not be discharged in the rivers. As 
It increases the dissolved oxygen content of river water, leading to a sudden rise 
in microbe population. This, in turn, reduces the level of oxygen in the river and 
makes it difficult for other kinds of organisms to survive. 
2. Surface run-off should not be discharged in the rivers as 
Surface run-off from farms carries organic and inorganic fertilizers into water 
bodies. This promotes the growth of algae, which reduces the dissolved oxygen 
level in water. Other living organisms in water bodies, including fish, cannot 
survive in such conditions. 
3. By not discharging the Untreated liquid waste into the rivers. Untreated liquid 
waste from kitchens and toilets is often discharged into rivers. This exposes 
people who use river water to diseases such as typhoid, cholera and amoebic 
dysentery. 
4. By taking dual care of leakage of Oil Spills in rivers. An oil spill occurs when crude 
oil, while being transported from one country to another, gets leaked into the sea. 
VALUES AND LIFE SKILLS 
Water is very important for sustaining life on earth. We should be careful while using 
water and should take steps to save our water resources. 
What are the things that you can do to save water? 
Answer: 
We can save water by doing following things, 
1. Check all faucets, pipes and toilets for leaks. 
2. Install water saving showerheads and ultra-low-flush toilets. 
3. Take shorter showers. 
4. Never use your toilet as a wastebasket. 
5. Turn off the water while brushing your teeth or shaving. 
EXERCISES 
A. Match the columns 
 
Answer: 
 
 
B. With the help of your atlas identify and mark the following in an outline map of 
the world. 
Question 1. 
The largest ocean in the world 
Answer: 
Pacific ocean. 
Question 2. 
The northernmost ocean 
Answer: 
Arctic ocean. 
Question 3. 
An inland sea in Eurasia 
Answer: 
Aral sea. 
Question 4. 
Two rivers in Europe 
Answer: 
Rhine and Danube. 
c. Answer the following questions in brief 
Question 1. 
Name the major water bodies on earth. 
Answer: 
The major water bodies on earth are oceans, seas, lakes and rivers. 
Question 2. 
What is the Ring of Fire? 
Answer: 
The pacific ocean is bordered by volcanic mountains on its edges. So it is termed as 
‘Ring of Fire’. 
Question 3. 
What is the difference between a gulf and a bay? 
Answer: 
A gulf is an inlet of the sea of large areal proportions while a bay is an open, curving 
indentation made by the sea or a lake into a coastline. Gulfs are more indented than 
bays and also more enclosed. 
Question 4. 
What do you understand by strait? Give an example. 
Answer: 
A strait is a narrow stretch of water that joins two large water bodies. The Strait of 
Gibraltar, for example, connects the Mediterranean Sea to the North Atlantic Ocean. 
Question 5. 
Mention the five Great Lakes of the USA. 
Answer: 
The five Great Lakes of the USA — Superior, Huron, Michigan, Ontario and Erie—are a 
group of five huge freshwater lakes located between the United States and Canada. 
They comprise the largest body of fresh water on earth. 
Question 6. 
Name the different parts of a river. 
Answer: 
The two main parts of a river are its source (from where the river originates) and the 
mouth (where the river enters the sea). 
Question 7. 
What is surface run-off? 
Answer: 
Surface run-off means the water from any source i.e. rain, river, etc which carries away 
the upper layer of soil, organic and inorganic fertilizers and make it a part of water cycle. 
D. Answer the following questions in one or two paragraphs 
Question 1. 
Why are oceans important? 
Answer: 
Oceans are very important for us for many reasons : 
1. Oceans are great storehouses of oil and mineral resources. 
2. They support a large variety of aquatic life. 
3. They facilitate international trade by providing trade routes. 
4. Oceans are also a source of food supply for many people around the world. 
Question 2. 
Describe the course of a river. 
Answer: 
The river passes through three courses from its source to mouth – upper, middle and 
lower. The upper course generally lies in mountains where land is steep and river flows 
very fast. At middle course the river speed decreases as plains have gentle slope. The 
flow of the river is nearly halted at its mouth (where it meets the sea or ocean). 
Question 3. 
Mention any five important rivers of the world, 
Answer: 
The river Nile in Africa, 6,695 km in length, is the world’s longest river. It flows out into 
the Mediterranean Sea. The Amazon, 6,640 km in length, flows through South America 
Page 5


POINTS TO REMEMBER 
? Nearly 71 per cent of the surface of earth is covered by water. 
? There are five large water bodies called oceans in the world. These are the Pacific 
Ocean, the Atlantic Ocean, the Indian Ocean, the Arctic Ocean and the Southern 
Ocean. Smaller water bodies include seas, lakes and rivers. 
? A river is a stream of water which flows in a channel from high ground to low 
ground and finally to a lake or a sea. The place where the river originates is called 
its source and the place where it ends is called its mouth. 
? The route or course of a river has three stages—the upper, middle and lower 
stages. In the upper stage the river is in the mountains, in the middle stage it flows 
over plains, and in the lower stage the river generally meets an ocean or a sea. 
? Almost all human activities generate waste which causes pollution. 
? Untreated liquid waste from kitchens and toilets of households, liquid wastes from 
thermal power plants, surface run-off from farms and oil spills are the main causes 
of water pollution. 
? Water pollution causes diseases such as typhoid, cholera and amoebic dysentery. 
IMPORTANT TERMS 
Ridge : A high pointed area near the top of a mountain. 
Surface run-off : Water from rain, melting snow, or other sources that flows over land 
and is a part of the water cycle. 
THINK AND ANSWER 
Everything that we do creates waste, which, in turn, creates pollution. How do you think 
you can reduce the amount of waste you generate? 
Answer: 
1. Liquid waste from thermal power plants should not be discharged in the rivers. As 
It increases the dissolved oxygen content of river water, leading to a sudden rise 
in microbe population. This, in turn, reduces the level of oxygen in the river and 
makes it difficult for other kinds of organisms to survive. 
2. Surface run-off should not be discharged in the rivers as 
Surface run-off from farms carries organic and inorganic fertilizers into water 
bodies. This promotes the growth of algae, which reduces the dissolved oxygen 
level in water. Other living organisms in water bodies, including fish, cannot 
survive in such conditions. 
3. By not discharging the Untreated liquid waste into the rivers. Untreated liquid 
waste from kitchens and toilets is often discharged into rivers. This exposes 
people who use river water to diseases such as typhoid, cholera and amoebic 
dysentery. 
4. By taking dual care of leakage of Oil Spills in rivers. An oil spill occurs when crude 
oil, while being transported from one country to another, gets leaked into the sea. 
VALUES AND LIFE SKILLS 
Water is very important for sustaining life on earth. We should be careful while using 
water and should take steps to save our water resources. 
What are the things that you can do to save water? 
Answer: 
We can save water by doing following things, 
1. Check all faucets, pipes and toilets for leaks. 
2. Install water saving showerheads and ultra-low-flush toilets. 
3. Take shorter showers. 
4. Never use your toilet as a wastebasket. 
5. Turn off the water while brushing your teeth or shaving. 
EXERCISES 
A. Match the columns 
 
Answer: 
 
 
B. With the help of your atlas identify and mark the following in an outline map of 
the world. 
Question 1. 
The largest ocean in the world 
Answer: 
Pacific ocean. 
Question 2. 
The northernmost ocean 
Answer: 
Arctic ocean. 
Question 3. 
An inland sea in Eurasia 
Answer: 
Aral sea. 
Question 4. 
Two rivers in Europe 
Answer: 
Rhine and Danube. 
c. Answer the following questions in brief 
Question 1. 
Name the major water bodies on earth. 
Answer: 
The major water bodies on earth are oceans, seas, lakes and rivers. 
Question 2. 
What is the Ring of Fire? 
Answer: 
The pacific ocean is bordered by volcanic mountains on its edges. So it is termed as 
‘Ring of Fire’. 
Question 3. 
What is the difference between a gulf and a bay? 
Answer: 
A gulf is an inlet of the sea of large areal proportions while a bay is an open, curving 
indentation made by the sea or a lake into a coastline. Gulfs are more indented than 
bays and also more enclosed. 
Question 4. 
What do you understand by strait? Give an example. 
Answer: 
A strait is a narrow stretch of water that joins two large water bodies. The Strait of 
Gibraltar, for example, connects the Mediterranean Sea to the North Atlantic Ocean. 
Question 5. 
Mention the five Great Lakes of the USA. 
Answer: 
The five Great Lakes of the USA — Superior, Huron, Michigan, Ontario and Erie—are a 
group of five huge freshwater lakes located between the United States and Canada. 
They comprise the largest body of fresh water on earth. 
Question 6. 
Name the different parts of a river. 
Answer: 
The two main parts of a river are its source (from where the river originates) and the 
mouth (where the river enters the sea). 
Question 7. 
What is surface run-off? 
Answer: 
Surface run-off means the water from any source i.e. rain, river, etc which carries away 
the upper layer of soil, organic and inorganic fertilizers and make it a part of water cycle. 
D. Answer the following questions in one or two paragraphs 
Question 1. 
Why are oceans important? 
Answer: 
Oceans are very important for us for many reasons : 
1. Oceans are great storehouses of oil and mineral resources. 
2. They support a large variety of aquatic life. 
3. They facilitate international trade by providing trade routes. 
4. Oceans are also a source of food supply for many people around the world. 
Question 2. 
Describe the course of a river. 
Answer: 
The river passes through three courses from its source to mouth – upper, middle and 
lower. The upper course generally lies in mountains where land is steep and river flows 
very fast. At middle course the river speed decreases as plains have gentle slope. The 
flow of the river is nearly halted at its mouth (where it meets the sea or ocean). 
Question 3. 
Mention any five important rivers of the world, 
Answer: 
The river Nile in Africa, 6,695 km in length, is the world’s longest river. It flows out into 
the Mediterranean Sea. The Amazon, 6,640 km in length, flows through South America 
and is the second longest river in the world. Other important rivers in the world are the 
Mississippi in the USA, the Rhine and the Danube 
in Europe and the Ganga in India. 
Question 4. 
Briefly describe the importance of rivers. 
Answer: 
Importance of Rivers — Rivers are an extremely important water resource: 
1. The river valleys and plains provide fertile soils and crops grow in plenty in and 
around the region, 
2. River water is used for human and animal consumption. Rivers provide abundant 
water supply to support large settlements. 
3. Rivers provide means of transport to carry humans and goods from one place to 
another and thus facilitate trade. 
4. River water is an important source of energy. It is used to power hydroelectric 
plants and helps in generation of electricity. It also thus helps the industries to 
grow. 
5. Rivers also provide the means for recreational activities. 
Question 5. 
What are the major causes of water pollution? 
Answer: 
The major causes of water pollution are liquid waste from thermal power plants, surface 
run-off, untreated liquid waste from industries, sewage, household waste and oil-spills. 
Question 6. 
What is an oil spill? Why is it harmful for the environment? 
Answer: 
When the crude oil gets leaked into the sea while being transported from one country to 
another because of an accident and hurricanes it is called oil – spill. The aquatic life 
gets poisoned as oxygen can’t reach them and leads to their death affecting the life 
cycle.