NCERT Solutions for Class 7 Social Science - Human Environment Interactions The Tropical and

1. Answer the following questions.

(i) Name the continent in which the Amazon Basin is located.
Ans: The Amazon Basin is located in South America.

(ii) What are the crops grown by the people of the Amazon Basin.
Ans: The people of the Amazon Basin primarily cultivate the following crops:

• Tapioca
• Pineapple
• Sweet potato
• Manioc (also known as cassava)
• Cocoa
• Coffee

These crops are essential for their diet and are often grown using a method called slash and burn agriculture. This technique involves clearing land by cutting down trees and burning the remains to enrich the soil.

(iii) Name the birds that you are likely to find in the rainforests of the Amazon.
Ans: Toucans, hummingbirds, and macaws are commonly found in the rainforests of the Amazon. These birds are known for their vibrant colours and unique features.

• Toucans: Recognised for their large, colourful bills.
• Hummingbirds: Notable for their small size and rapid wing beats.
• Macaws: Known for their brilliant plumage and social behaviour.

These birds contribute to the rich biodiversity of the Amazon rainforest.

(iv) What are the major cities located on the River Ganga?
Ans: The major cities located along the River Ganga include:

• Allahabad
• Kanpur
• Varanasi
• Patna
• Kolkata

All these cities have a population of over ten lakhs and play a significant role in the region.

(v) Where is the one-horned rhinoceros found?
Ans: The one-horned rhinoceros is primarily found in the Brahmaputra plain. This region is known for its rich biodiversity and is home to various wildlife species.

2. Tick the correct answer.

(i) Toucans are a type of:

(a) birds

(b) animals

(c) crops

(d) trees

Ans: (a)

Toucans are colorful, tropical birds found in rainforests, particularly in Central and South America. They are known for their large, bright bills and are often associated with the Amazon Rainforest.

(ii) Manioc is the staple food of:

(a) Ganga Basin

(b) Africa

(c) Amazon

(d) Asia

Ans: (c)

Manioc, also known as cassava, is a root vegetable that serves as a staple food for people living in the Amazon Basin. It is well-suited to the tropical climate and is a significant source of carbohydrates.

(iii) Kolkata is located on the river:

(a) Orange

(b) Hooghly

(c) Bhagirathi

(d) Beas

Ans: (b)

Kolkata, the capital of West Bengal, is situated on the banks of the Hooghly River. This river is a distributary of the Ganges and is crucial for transportation and trade in the region.

(iv) Deodars and firs are a type of:

(a) Coniferous trees

(b) Deciduous trees

(c) shrubs

(d) Herbs

Ans: (a)

Deodars and firs are evergreen trees that belong to the coniferous forest category. These trees are adapted to cold climates, with needle-like leaves and cones, and are commonly found in mountainous regions like the Himalayas.

(v) The Bengal tiger is found in:

(a) mountains

(b) delta area

(c) Amazon

(d) plains

Ans: (b)

The Bengal tiger is primarily found in the Sundarbans delta, which spans parts of India and Bangladesh. This delta area is formed by the confluence of the Ganga, Brahmaputra, and Meghna rivers and is home to a unique mangrove ecosystem.

3. Match the following.

Ans:

4. Give reasons.

(i) The rainforests are depleting.
Ans:

•  A huge number of rainforests have been destroyed, because of wide-scale development and industrial activity. 
• Another reason is the clearing of land for agricultural and mining incorporation of trees into industrial operations. Industrial operations necessitate the use of wood. 
• The top soil is being washed away as a result of deforestation. As a result, there is no room for tree growth. Therefore, rainforests are decreasing.

(ii) Paddy is grown in the Ganga-Brahmaputra plains.
Ans:

• For agricultural production, the Ganga-Brahmaputra plains provide flat, rich terrain with alluvial soil. 
• The amount of rainfall in this region is also fairly significant, making it an ideal location for the cultivation of rice which requires a lot of water to flourish. 
• Furthermore, the climate in this area is ideal for rice cultivation. So Paddy is grown on the Ganga- Brahmaputra plains.

5. Map skills.

(i) On an outline map of the Indian Sub-continent, draw the rivers Ganga and Brahmaputra from the source to the mouth. Also, show the important tributaries of both rivers.

(ii) On the political map of South America, draw the equator and mark the countries it passes through.

For (i):

For (ii):

6. For fun.

Make a collage to show places of attractions in India. You can divide the class in different groups to show attractions based on mountain landscapes, coastal beaches, wildlife sanctuaries and places of historical importance. 
Ans: Students are advised to try these questions independently. 

7. Activity

Collect under mentioned material and observe how destruction of trees effect the soil cover.

Material
(i) Three small flowerpots or food cans (e.g., cold drinks tin cans),
(ii) one big can with holes punched in the bottom (this will act as a sprinkling can),
(iii) twelve coins or bottle caps
(iv) soil.

Steps
Take three small cans or pots. Fill them with soil till the top. Press the soil to make it level with the top of the can. Now put four coins or bottle caps on the soil of each can. Take the big can that has been punched with holes and fill it with water. You can also take the sprinkling can from your garden. Now, sprinkle water on the three cans. On the first can sprinkle water very slowly so that no soil splashes out. Let moderate amount of water be sprinkled on the second can. On the third can, sprinkle the water heavily. You will observe that unprotected soil splashes out. Where the ‘rain’ is heavy the amount of soil that splashes out is the maximum and least in case of the first can. The coins or caps represent the tree covers. It is clear that if the land is cleared completely of the vegetation, the soil cover will quickly disappear.
Ans: Students are advised to try these questions independently.