Ch-16 Management of Natural Resources (Exercise) Page279

Question 4:	How can you as an individual contribute or make a difference to the management of (a) forests and wildlife, (b) water resources and (c) coal and petroleum?
Answer :	(a) Forest and wildlife: (i) We should protest against the cutting of trees (deforestation). (ii) We should protest against the poaching of wild animals. (iii) We should stop the annexation of forest land for our use. (b) Water resources: (i) Turn the taps off while brushing or bathing and repair leaking taps. (ii) We should practice rainwater harvesting. (iii) We should avoid the discharge of sewage and other wastes into rivers and other water resources. (c) Coal and petroleum: (i) We should take a bus or practice car pooling to avoid excessive use of petroleum. (ii) We should stop using coal as a fuel (angithis). (iii)We should use alternative sources of energy such as hydro-energy and solar energy instead of depending largely on coal and petroleum.
Question 5:	What can you as an individual do to reduce your consumption of the various natural resources?
Answer :	Natural resources such as water, forests, coal and petroleum, etc. are important for the survival of human beings. The ways in which we can reduce the consumption of various natural resources are as follows: (i) We should stop the cutting of trees (deforestation). (ii) We should use recycled paper to reduce the cutting down of trees. (iii) We should not waste water. (iv) We should practice rainwater harvesting. (v) We should practice car pooling to avoid the excessive use of petroleum. (vi) We should use alternative sources of energy such as hydro-energy and solar energy.
Question 6:	List five things you have done over the last one week to − (a) conserve our natural resources (b) increase the pressure on our natural resources
Answer :	(a) To conserve our natural resources: (i) Travel by a CNG bus for long distances and walk for short distances. (ii) Use recycled paper (iii) Throw biodegradable and non-biodegradable waste into separate bins (iv) Plant trees (v) Harvest rainwater (b) To increase the pressure on our natural resources: (i) Use non-renewable resources of energy (ii) Waste water (iii) Waste electricity (iv) Use plastics and polythene bags for carrying goods (v) Use escalators
Question 7:	On the basis of the issues raised in this chapter, what changes would you incorporate in your life-style in a move towards a sustainable use of our resources?
Answer :	One should incorporate the following changes in life-style in a move towards a sustainable use of our resources: (i) Stop cutting trees and practice plantation of trees. (ii) Stop using plastic and polythene bags for carrying goods. (iii) Use recycled paper. (iv) Throw biodegradable and non-biodegradable waste into separate bins. (v) Waste minimum amount of water while using and repair leaking taps. (vi) Practice rainwater harvesting. (vi) Avoid using vehicles for short distances. Instead, one can walk or cycle to cover short distances. To cover long distances, one should take a bus instead of using personal vehicles. (vii) Switch off electrical appliances when not in use. (viii) Use fluorescent tubes in place of bulbs to save electricity. (ix) Take stairs and avoid using lifts. (x) During winters, wear an extra sweater to avoid using heaters.

Ch-16 Management of Natural Resources (Exercise) Page278

Question 1:	What changes would you suggest in your home in order to be environment-friendly?
Answer :	Changes that can be undertaken in our homes to be environment-friendly are listed below: (i)Switch off the electrical appliances when not in use. (ii)Turn the taps off while brushing or bathing and repair the leaking taps. (iii)Throw biodegradable and non-biodegradable waste into separate bins. (iv)Construct composting pits. (v)Food items such as jam, pickles, etc., come packed in plastic bottles. These bottles can later be used for storing things in the kitchen.
Question 2:	Can you suggest some changes in your school which would make it environment-friendly?
Answer :	Changes that can be undertaken in our schoolsto make it environment friendly are listed below: (i) Electricity can be saved by switching off lights and fans when not required. (ii) Turn the taps off when not in use. (iii) Biodegradable and non-biodegradable wastes should be thrown into separate bins
Question 3:	We saw in this chapter that there are four main stakeholders when it comes to forests and wildlife. Which among these should have the authority to decide the management of forest produce? Why do you think so?
Answer :	The forest department of the government should have the authority to decide the management of forest produces. This is because the forest department is the care taker of the forest land and is responsible for any damage to the forest.

Ch-16 Management of Natural Resources (Question) Page276

Question 1:	Find out about the traditional systems of water harvesting/management in your region.
Answer :	One of the traditional systems of water harvesting used in our region is tanks.
Question 2:	Compare the above system with the probable systems in hilly/mountainous areas or plains or plateau regions
Answer :	In plains, the water harvesting structures are crescent-shaped earthen embankments. These are low, straight, and concrete. In hilly regions, the system of canal irrigation called Kulhs is used for water harvesting. This involves a collection of rain water in a stream, which is then diverted into man-made channels down the hill sides.
Question 3:	Find out the source of water in your region/locality. Is water from this source available to all people living in that area?
Answer :	The source of water in our region is ground water. Water from the source is available to all the people living in that area

Ch-16 Management of Natural Resources (Question) Page273

Question 1:	Why should we conserve forests and wildlife?
Answer :	We should conserve forests and wildlife to preserve the biodiversity (range of different life-forms) so as to avoid the loss of ecological stability. A large number of tribes are the habitants in and around the forests. If the forests are not conserved, then it may affect these habitants. Witho
Question 2:	Suggest some approaches towards the conservation of forests.
Answer :	Some approaches towards the conservation of forests are as follows: (a) People should show their participation in saving the forest by protesting against the cutting of trees. For example, Chipko Andolan (b) Planting of trees should be increased. Rate of afforestation must be more than that of deforestation. (c) Some people cut precious trees such asChandan to earn money. Government should take legal steps to catch these wood smugglers. (d) Habitants of forests must not be bothered by the forest officials. Otherwise, this would result in the clash between tribal people and the government officials, thereby enhancing the naxal activities in forests.

Ch-16 Management of Natural Resources (Question) Page269

Question 1:	What changes can you make in your habits to become more environment-friendly?
Answer :	We should switch off the electrical appliances when not in use. Water and food should not be wasted. Close the tap when not in use. Dump the objects made of plastic and glass in designated recycling boxes. Plastic, paper, or glass must be recycled or reused and not dumped with other wastes. This is because objects made of plastic do not get decomposed easily. Besides soil fertility, they badly affect our environment. We should dispose the wastes safely and not disperse in public places. These are a few things that can be done to become more environment- friendly.
Question 2:	What would be the advantages of exploiting resources with short-term aims?
Answer :	There should be a judicious use of natural resources as they are limited in nature. We should not exploit resources for our short term gains as this would only lead to depletion of natural resources for the present generation as well as generations to come. Hence, we can say that there are hardly any advantages of exploiting natural resources for short term gains.
Question 3:	How would these advantages differ from the advantages of using a long-term perspective in managing our resources?
Answer :	In the case of a long-time perspective in managing our resources, these resources will last for the generations to come. This management ensures uniform distribution among the people. It conserves the natural resources for many years and not just for a few years, as in the case of a short-term perspective in conserving natural resources.
Question 4:	Why do you think there should be equitable distribution of resources? What forces would be working against an equitable distribution of our resources?
Answer :	Natural resources of the Earth must be distributed among the people uniformly so that each and every one gets his share of the resource. Human greed, corruption, and the lobby of the rich and powerful are the forces working against an equitable distribution of resources.

Ch-15 Our Environment (Exercise) Page264

Question 4:	What will happen if we kill all the organisms in one trophic level?
Answer :	Various trophic levels are connected through the food chains. If all the organisms of any one trophic level are killed, then it will disrupt the entire food chain. For example, in a food chain, if all the plants are killed, then all the deer will die due to lack of food. If all the deer are dead, then soon the tigers will also die. Due to the death of these animals, the decomposer’s population will rise in that area. This is just an example of one food chain. However, in nature, food chains are not isolated. They are interconnected in the form of food web. Therefore, killing all the plants of an area will not only affect the deer, it will also affect other herbivores such as goat, cattle, sheep, etc.
Question 5:	Will the impact of removing all the organisms in a trophic level be different for different trophic levels? Can the organisms of any trophic level be removed without causing any damage to the ecosystem?
Answer :	Organisms of all trophic levels are equally important and are an integral part of the ecosystem. If all the producers are removed, then it will affect all the herbivores as it is their primary food source. Death of herbivores will soon affect the primary carnivores and so on. Now let us suppose that all the deer (herbivores) are killed in a region. This can lead to an increase in the number of producers. At the same time, there will be an increase in the number of other herbivores such as rabbits, goat, sheep, etc. due to less competition. This will also lead to the increase in population of only consumers of these increased herbivores. Thus, the balance in the ecosystem gets disturbed if any of its component organisms are removed
Question 6:	What is biological magnification? Will the levels of this magnification be different at different levels of the ecosystem?
Answer :	Biomagnification is the increase in the concentration of pollutants or harmful chemicals within each step of the food chain. The levels of biomagnification will be different at different trophic levels. For example, in a pond of water, DDT was sprayed and the producers were found to have 0.04 ppm concentration of DDT. Since many types of planktons are eaten by some fishes and clams, their body accumulates 0.23 ppm of DDT. Sea gull that feeds on clams accumulates more DDT as one sea gull eats many clams. Hawk, the top carnivore, has the highest concentration of DDT. Biomagnification
Question 7:	What are the problems caused by the non-biodegradable wastes that we generate?
Answer :	Non-biodegradable substances affect the environment in the following ways: (i) Since the non-biodegradable substances cannot be broken down, they get accumulated and thus contaminate the soil and the water resources. (ii) These substances, when accidentally eaten by some stray animal, can harm them and can even cause their death. (iii) These substances occupy more space in the landfills and require special disposal techniques. (iv) These materials can accumulate in the environment and can also enter the food chain.
Question 8:	If all the waste we generate is biodegradable, will this have no impact on the environment?
Answer :	Generation of only biodegradable waste will have a positive impact on the environment. There will not be any pollution caused by the non-biodegradable wastes. The problem associated with waste management and disposal will also not occur. The population of decomposers will increase to breakdown the extra biodegradable waste generated.
Question 9:	Why is damage to the ozone layer a cause for concern? What steps are being taken to limit this damage?
Answer :	Ozone depletion occurs widely in the stratosphere. However, it is more prominent over the Antarctic region and is known as the ozone hole. Diagram representing ozone hole Consequences of ozone depletion: It causes skin darkening, skin cancer, ageing, and corneal cataracts in human beings. It can result in the death of many phytoplanktons that leads to increased global warming. To limit the damage to the ozone layer, the release of CFCs into the atmosphere must be reduced. CFCs used as refrigerants and in fire extinguishers should be replaced with environmentally-safe alternatives. Also, the release of CFCs through industrial activities should be controlled.

Ch-15 Our Environment (Exercise) Page264

Question 1:	Which of the following groups contain only biodegradable items? (a) Grass, flowers and leather (b) Grass, wood and plastic (c) Fruit-peels, cake and lime-juice (d) Cake, wood and grass
Answer :	(c)Fruit-peels, cake, and lime-juice (d)Cake, wood, and grass
Question 2:	Which of the following constitute a food-chain? (a) Grass, wheat and mango (b) Grass, goat and human (c) Goat, cow and elephant (d) Grass, fish and goat
Answer :	(b) Grass, goat, and human.
Question 3:	Which of the following are environment-friendly practices? (a) Carrying cloth-bags to put purchases in while shopping (b) Switching off unnecessary lights and fans (c) Walking to school instead of getting your mother to drop you on her scooter (d) All of the above
Answer :	(d) All of the above