Chapter 3: Conservation of Plants and Animals | Science Class 8th

Chapter 3: Conservation of Plants and Animals | Science Class 8th

Q1: Fill in the blanks:

(a) A place where animals are protected in their natural habitat is called a __ .

(b) Species found only in a particular area are known as ______.

(c) Migratory birds fly to far-away places because of ______ changes.

Ans.

(a)  A place where animals are, protected in their natural habitat is, called a Sanctuary.

(b) Species found only in a particular area are known as Endemic.

(c) Migratory birds fly to far-away places because of Climatic Changes.

Q2. Differentiate between the following.

(a) Wildlife sanctuary and biosphere reserve

(b) Zoo and wildlife sanctuary

(c) Endangered and extinct species

(d) Flora and fauna

Ans:

(a) Wildlife Sanctuary and Biosphere Reserve.

Wildlife sanctuary:

• It is an area within which animals are, protected from possible dangers such as hunting. Their habitat is, also conserved in this area.
• It provides protection and suitable living conditions for wild animals.
• Pachmarhi Sanctuary is a wildlife sanctuary.

Biosphere Reserve:

• It is, a large protected area constructed for the conservation of biodiversity.
• It helps in the conservation of various life forms such as plants, animals, and micro-organisms.
• Pachmarhi biosphere reserve is a popular biosphere reserve.

(b) Zoo and wildlife Sanctuary.

Zoo:

• It is a facility in which animals are, kept for public exhibition.
• It is an artificial habitat.

Wildlife Sanctuary:

• It is an area within which animals are, protected from possible dangers such as hunting. Their habitat is, also conserved in the area.
• It conserves the natural habit of the animals.

(c) Endangered and Extinct Species.

Endangered Species:

• It is a population of species that is on the verge of becoming extinct.
• Blue whale, tiger, leopard, etc. are examples of endangered species.

Extinct Species:

• It is a population of species that no longer exists. Hence, it is extinct.
• Dodo, passenger pigeon, etc. are examples of extinct species.

(d) Flora and Fauna.

Flora:

• It refers to all living plants in a particular area.
• Sal, teak, mango, etc. form the flora of Pachmarhi biosphere reserve.

Fauna:

• It refers to all living animals in a particular area.
• Leopard, wolf, wild dog, etc form the fauna of Pachmarhi biosphere reserve.

Q3. Discuss the effects of deforestation on the following.

(a) Wild animals

(b) Environment

(c) Villages (Rural areas)

(d) Cities (Urban areas)

(e) Earth

(f) The next generation

Ans. (a) Effects of deforestation on wild animals:

Deforestation is when trees or other vegetation are taken out of a place for commercial, agricultural, or other reasons. trees and other types of flora from various animals' habitats. Therefore, if an animal's environment is destroyed, their population will inevitably decrease.

(b) Effects of deforestation on the environment:

In order to complete photosynthesis, plants take CO2 from the environment. CO2 levels in the atmosphere will rise if plants are eliminated. Because of this, CO2 will trap more heat radiation, contributing to the warming trend. The natural water cycle on Earth will be hampered by a rise in global temperature. As a result, the pattern of rainfall will shift. Floods or droughts can result from this.

(c) Effects of deforestation on villages:

Plant roots bind soil fragments together. The top layer of soil will be quickly removed in the absence of plants by the action of swift winds or flowing water. Soil erosion is more likely as a result of deforestation. Soil loses humus as a result, becoming less fertile. As a result, a lush land that provides a livelihood for farmers in villages is turned into a desert.

(d) Effects of deforestation on cities:

Cities that are deforested may be more susceptible to natural disasters like floods and droughts. Additionally, it may contribute to global warming because of a rise in CO2 levels in the atmosphere brought on by industrial and vehicular pollutants. The local water cycle may be hampered by this temperature rise.

(e) Effects of deforestation on the Earth:

Deforestation increases the likelihood of desertification, droughts, floods, and other natural disasters. Additionally, deforestation can raise the Earth's CO2 concentration. It will cause global warming, which is an increase in temperature. The entire natural water cycle will be disturbed as a result. This ups the likelihood of natural disasters.

(f) Effects of deforestation on the next generation:

Our ecology is slowly changing as a result of deforestation. It is to blame for numerous global issues, including soil erosion, the greenhouse effect, droughts, floods, and global warming. As a result, the consequences of deforestation will be devastating for the coming generation.

Q4. What will happen if:

(a) we go on cutting trees.

(b) the habitat of an animal is, disturbed.

(c) the top layer of soil is, exposed.

Ans.

(a) If we continue to clear forests, many animals' natural habitats will be completely eliminated. As a result, many areas' biodiversity will suffer significantly. Additionally, the Earth's temperature will rise due to global warming, which could disrupt the natural water cycle. As a result, the pattern of rainfall will shift. Floods or droughts can result from this. Additionally, this will raise the possibility of desertification, soil erosion, and other natural disasters.

(b) An animal receives all of its needs, including food, shelter, and safety, from its habitat. An animal will be compelled to look in other places for food and refuge if its environment is damaged. The method could result in the animal being killed by other animals.

(c) If the top soil layer is uncovered, the hard, rocky lower layer of soil will progressively become visible. Because it has less humus, this type of soil is less fruitful. The land will become infertile or barren if soil erosion continues.

Q5. Answer in brief:

(a) Why should we conserve biodiversity?

(b) Protected forests are also not completely safe for wild animals. Why?

(c) Some tribals depend on the jungle. How?

(d) What are the causes and consequences of deforestation?

(e) What is Red Data Book?

(f) What do you understand by the term migration?

Ans.

(a) The amount and variety of different life forms, such as plants, animals, and microorganisms, in a region are known to as biodiversity. For survival, both plants and animals rely on one another. This implies that the death of one of the two will have an impact on the survival of the other. Therefore, we must protect biodiversity in order to keep nature in its proper balance.

(b) Because humans who live nearby or adjacent to woods use the resources from the forests to meet their own needs, protected forests are not entirely safe for wild animals. Wild animals are slaughtered during this operation and sold for high prices.

(c) Tribals gather food, fodder, and fallen branches of trees from forests. Hence, they depend on forests for their daily requirements.

(d) Causes of deforestation: (i) Forests are, cleared for accommodating expanding urban areas and for fulfilling their ever-increasing requirements. (ii) Forests are, destroyed to clear land for crops and cattle grazing. (iii) Trees are, cut down to be, used for firewood.

Consequences of deforestation: (i) Soil erosion (ii) Loss of biodiversity (iii) Floods and droughts (iv) Climate change due to global warming (v) Disruption of the water cycle.

(e) Red Data Book is a sourcebook that maintains an international list of all endangered animal and plant species. This book is, maintained by IUCN (International Union for Conservation of Nature and Natural resources).

(f) Migration refers to the movement of an organism or a group of organisms from its natural habitat to another place at a particular time every year. Organisms migrate from one place to another to avoid inhabitable climatic conditions or for breeding.

Q6. In order to meet the ever-increasing demand in factories and for shelter, trees are being continually cut. Is it justified to cut trees for such projects? Discuss and prepare a brief report.

Ans:

No. Cutting down trees to satisfy the rising needs of the human population is not at all reasonable. Many different creatures, including wild animals, can be found in forests. As they emit O2 and take in the dangerous CO2 gas from the atmosphere, they offer us clean air. They do this to stop the atmosphere from heating up too much. They stop soil erosion as well as natural disasters like floods and droughts. They support biodiversity preservation and improve soil fertility. In order to meet the needs of the expanding human population, forests must be cut down, which will result in a number of issues including soil erosion, greenhouse impact, droughts, floods, and more. The natural order will be upset if woods are destroyed. Hence, forests must be conserved.

Q7. How can you contribute to the maintenance of the green wealth of your locality? Make a list of actions to be taken by you.

Ans:

By taking care of the plants and trees that are growing in or around my locality, I may contribute to preserving its natural beauty. I am able to grow my tree population. By educating my neighbours on the value of growing trees, I can also inspire them to plant more trees. I can educate young children about the harm deforestation causes to the environment and the globe. A very small amount of their time will be required if I ask them to water the plants every day. I think maintaining old trees is vital, but so is planting new ones.

Q8. Explain how deforestation leads to reduced rainfall.

Ans:

Deforestation occurs when trees or other vegetation are taken out of a place for commercial, agricultural, or other reasons. CO2 from the atmosphere is absorbed by plants or trees. CO2 levels in the atmosphere will rise if plants are eliminated. Global warming will result from more heat radiations being trapped in the atmosphere due to the high levels of CO2. The Earth's natural water cycle will be hampered by this rise in temperature. The pattern of rainfall will alter as a result of the interruption to the water cycle. Droughts may be brought on by a decrease in the amount of rain.

Q9. Find out about national parks in your state. Identify and show their location on the outline map of India.

Ans: One of the national parks located near Delhi is the Corbett National Park.

Q10. Why should the paper be saved? Prepare a list of ways by which you can save paper.

Ans:

Since it takes about seventeen mature trees to produce one tonne of paper, the paper should be saved. As is well known, trees help keep the natural world in balance. Therefore, we must save paper in order to save trees and prevent the negative effects of their extinction on living things.

Ways by which paper can be saved: (i) Collect used paper and recycle it. (ii) Use both sides of a paper for writing.  (iii) Spread awareness about the importance of paper. (iv) Use paper intelligently.