Chapter 11. Bio-diversity Textbook Solutions

NIOS Social Science Class 10 Chapter 11 Solutions

INTEXT QUESTIONS 11.1

1. “Bio-diversity is fundamental to the existence of life on the earth” Justify the statement by giving any two reasons.

Ans: Biodiversity is fundamental to the existence of life on the earth because it is extremely valuable in different facets of life, which include providing food, water, fiber, fuel, etc., and regulating climate and diseases.

2. Explain hotspots in 30 words.

Ans: A biodiversity hotspot is a region with a high level of endemic species. Endemic species are those species that are found in a certain limited area.

INTEXT QUESTIONS 11.2

1. Why are the tropical rain forests called evergreen forests? Explain in 30 words.

Ans: Trees in these forests remain green all year round as the climate of the region is warm and wet throughout the year. The leaves of the trees do not fall in any particular season. Hence they are evergreen.

2. Give reasons

(i) Tidal Forest areas along the eastern coast experienced severe destruction during cyclones in recent years because

(ii) Himalayan Forests have been economically more exploited in comparison to Tropical Evergreen Forests because

Ans:

(i) Tidal forests along the eastern coast protect against cyclones. But in recent years, due to massive deforestation of these forests, these areas have been experiencing severe destruction during cyclones.
(ii) Tropical evergreen forest has dense and mixed vegetation of all kinds, and hence, their economic exploitation is not viable, whereas species in the Himalayan vegetation are less dense and found in pure stands.

INTEXT QUESTIONS 11.3

1. Fill in the blanks correctly from the alternatives provided in the bracket:-

(i) At present there are ……………….. wild life sanctuaries (441/551)

Ans: 551

(ii) ……………….. in Assam is known for the Indian Rhinoceroses. (Manas/Kaziranga)

Ans: Kaziranga

(iii) Harike Wetlands is located in ……………….. (Punjab/ Himachal Pradesh)

Ans: Punjab

(iv) ……………….. biosphere reserve is in the state of Tamil Nadu. (Gulf of Mannar/Pachmarhi)

Ans: Gulf of Mannar

2. Define Wetlands

Ans: A wetland is an area of land whose soil is saturated with moisture either permanently or seasonally. Such areas may also be covered partially or completely by shallow pools of water.

3. Make a list of any three efforts you can make to safeguard the biodiversity of your surroundings?

Ans: Some of the efforts you can make to safeguard the biodiversity of your surroundings are:

(i) stop cutting trees
(ii) plant more trees
(iii) protect all animals
(iv) establishment of hospitals for injured birds or animals
(v) stop throwing garbage and polluting the environment.

TERMINAL EXERCISES

1. Define biodiversity. Explain the interrelationship between natural vegetation, wildlife and microorganisms.

Ans: Biological diversity or biodiversity is a term we use to describe the variety of life on Earth, which includes different components of the physical environment such as temperature, soil, and water. Natural vegetation refers to all types of plants on earth. Wildlife includes all kinds of animals, birds, insects, reptiles, and aquatic life forms. Microorganisms are the remaining invisible forms of life that also play a significant role.

2. Describe in brief the characteristics and distribution of Tropical Evergreen Forests in India.

Ans:

Trees in Tropical Evergreen forests remain green all year round as the climate of the region is warm and wet throughout the year.
The leaves of these trees do not fall in any particular season. Hence, they are evergreen.
These forests are found in areas having more than 200 cm of rainfall and a short dry season.
The trees reach a height of up to 60 meters or even more.
It has a dense and mixed vegetation of all kinds, including trees, shrubs, climbers, creepers, epiphytes, and ferns, giving it a multilayered structure.
The number of species of trees is very large in a small area.
Rosewood, ebony, mahogany, rubber, jack wood, and bamboo are the important species of trees found in Tropical Evergreen Forests.
In India, this type of vegetation is found in the areas of heavy rainfall in the Western Ghats, the upper parts of Assam, and the islands of Lakshadweep, Andaman, and Nicobar.
Hardwood from these forests is used for furniture, handicraft etc.
They prevent landslides and soil erosion.

3. Give any two differences between the moist deciduous forests and the dry deciduous forests in India.

Ans:

Moist Deciduous Forests	Dry Deciduous Forests
Teak, Bamboo, Sal, Shisham, Sandalwood, Khair, Kusum, Arjun, Mahua, Jamun, and Mulberry are the important species of trees found in these forests.	Spread in the areas receiving rainfall between 75 to 100 cms annually.
Found in the areas of rainfall between 100 and 200 cm.	Spread in the areas receiving rainfall between 75 and 100 cms annually.
Found in the interior parts of the Peninsular plateau and the plains of Uttar Pradesh, Madhya Pradesh, and Bihar.	Tree species that grow in this vegetation are Teak, Sal, Peepal, and Neem.

4. State three objectives for establishment of biosphere reserves in India.

Ans: The main objectives are,

To conserve the diversity and integrity of the life of plants, animals, and microorganisms.
To promote ecofriendly sustainable life in the areas
To promote ecological conservation, research, education, awareness, and training in the life of such areas.

5. What are the main causes of loss of biodiversity? State any four.

Ans: Increasing population and changing lifestyle lead to the commercial exploitation of natural resources. This results in loss of biodiversity. Consequently, it is adversely affecting the ability of nature to continue delivering the goods and services for human existence. The loss of biodiversity affects not only the physical environment but also the social, cultural, religious, and spiritual well-being of human life.

6. Justify the need for conservation of natural vegetation, wildlife, and microorganisms with suitable reasons.

Ans:

(i) Vegetation is a key component of biodiversity. Without vegetation, the animals and some micro-organisms would die for lack of habitat, food and oxygen.
(ii) Plant’s root systems hold the soil together, protecting it from being blown away by the wind or washed away by water.
(iii) Vegetation plays a major role in the water cycle. Plants provide a link between the ground and the atmosphere by drawing water up from the ground and releasing it through the leaves into the air as water vapour.
(iv) Vegetation is a natural barrier and slows down the flow of water over the surface of the ground.
(v) Through photosynthesis, vegetation removes carbon dioxide from the air and replaces it with oxygen. Other pollutants can also be filtered out of the air by vegetation.
(vi) Vegetation acts as a stabilising influence in the greenhouse effect. Conversely, clearing of vegetation releases high amounts of carbon dioxide, the main greenhouse gas.
(vii) Wildlife plays an important role in maintaining a balanced food chain. This role helps in maintaining ecological balance, resulting in healthy biodiversity.
(viii) The invisible micro-organism plays an important role as scavengers, improving soil fertility, and is of immense medicinal value.

7. Study the table given below and answer the following questions.

Natural Parts/Wildlife Sanctuary	Protected Wild Animals
1. Kaziranga	1. Tiger
2. Manas	2. Elephant
3. Periyar	3. Musk Deer
4. Corbett	4. Lion
5. Dachigram	5. Rhino
	6. Wild Buffalo
	7. Panther
	8. Bear

(a) Match the name of the animal to the national park in which they are protected?

(b) Encircle the animals which are not protected in any national park?

(c) Write the name of the animal which is protected in more than one National Park?

Ans: (a)

Natural Parts/Wildlife Sanctuary	Protected Wild Animals
1. Kaziranga	6. Wild Buffalo
2. Manas	5. Rhino
3. Periyar	2. Elephant
4. Corbett	1. Tiger
5. Dachigram	3. Musk Deer

(b) Animals that are not protected: Bear

8. Refer to Figure No.11.3

(a) Find out the type of vegetation in your state.

(b) Which areas have thorn forests?

(c) Which areas have tidal forests, and why are they restricted to those areas?

Ans:

Individual answer.
Gujarat, Rajasthan, Madhya Pradesh, Chhattisgarh, Uttar Pradesh, Haryana, Karnataka, Andhra Pradesh, and Maharashtra.
Deltas of the Sundarbans, Mahanadi, the Godavari, Krishna, Kaveri rivers, and in the Andaman and Nicobar Islands.