NCERT Solution Class 10 Science Biology
Questions, Page 271
➤ CBSE Study Materials for Class 10th
Q.1. What changes can you make in your habits to become more environment friendly?
Answer:
We can make the following changes in our habits to become more environment friendly :
- Switch off the lights, fans, TV, geyser and other electrical appliances when not needed.
- Stop using polythene bags and start using bags made of cloth or jute.
- Start going to nearby school on bicycle instead of asking parents to drop us on scooter or car.
- Stop using any products made of animal skin, fur or ivory.
- Collect used articles made of paper, plastic, glass and metals, and send them for recycling.
Q.2. What would be the advantages of exploiting resources with short term aims ?
Answer:
If the resources are exploited to the hilt with short-term aims, then the present generation will benefit too much. For example, the exploitation of resources with short-term aims would provide more than sufficient food, water, and energy to all the people in the present generation.
Q.3. How would these advantages differ from the advantages of using a long-term perspective in managing our resources ?
Answer:
Exploiting the natural resources with short-term aims would be too much beneficial for the present generation but no resouces will be left for the needs of future generations. On the other hand, the management of natural resources on a long-term perspective will meet the basic needs of the present generation and also ensure that sufficient natural resouces are left for the needs of future generations.
Q.4. Why do you think there should be equitable distribution of natural resouces ? What forces would be working against an equitable distribution of resources ?
Answer:
At present, the rich and powerful people are cornering a major share of the country's natural resources (such as irrigation water from canals). There should be an equitable distribution of natural resources so that even poor people may benefit more by using them. Some vested interests with money and influence are working against the equitable distribution of natural resources.
Questions, Page 275
Q.1. Why should we conserve forests and wildlife ?
Answer:
- We should conserve forests because they provide raw materials for a number of industries like timber industry, paper industry, lac industry and sports equipment industry. Forests prevent floods and soil erosion. Forests help in bringing sufficient rainfall by maintaining a perfect water cycle in nature. Forests also provide natural habitat to wild animals and birds, and help in their conservation. Forests are essential for maintaining the ecologocal balance by preserving the biodiversity (large number of species of plants and animals).
- The wild animals and birds which live on a forest are called 'wildlife'. We should conserve wildlife to maintain ecological balance in nature. For example, it is necessary to conserve wild animals like lions and tigers to maintain the forest ecosystem because they keep the population of herbivorous animals (like deer) under control and save the vegetation from overgrazing and its ill effects on environment. This is because overgrazing destroys the green plants and reduces the rainfall in that area. Due to less rainfall, the lush green forest environment can turn into a desert over a period of time. Wildlife should also be conserved to prevent the extinction of rare varieties of animals and birds from this earth.
Q.2. Suggest some approaches towards the conservation of forests.
Answer:
Some of the measures which can be taken for the conservation of forests are as follows :
- The indiscriminate and unauthorised felling (cutting) of forest trees for timber trade and firewood should be curbed immediately.
- In case of Government authorised felling of forest trees, for every acre of forest cut down, an equal area of land should be planted with saplings of trees to make up for the loss in the long run.
- Overgazing of forest vegetation by the cattle of local people should be prevented.
- Measures should be taken to prevent and control forest fires.
- The local peope of villages in and around the forest should be involved in the conservation of forests by giving employment in silviculture and harvesting operations of the forest.
Questions, Page 278
Q.1. Find out about the traditional systems of water harvesting/management in your region.
Answer:
The traditional systems of water harvesting in our region are ponds and lakes where rainwater is stored.
Q.2. Compare the above systems with the probable systems in hilly/mountainous areas or plains or plateau regions.
Answer:
Dams are built over rivers in hilly/mountainous areas. They are more advantageous because they store running river water which can be used to generate electricity. Moreover, since the water stored in dam keeps flowing to turn the turbines, it does not act as a breeding ground for mosquitoes (which spread malaria). The stagnant water in ponds and lakes, however, become a breeding ground for mosquitoes.
Q.3. Find out source of water in your region/locality. Is water from this source available to all people living in that area ?
Answer:
In our region, the source of water is a river flowing through the city and some tube - wells dug at various places in the area. The river water and tube well water is supplied to the homes through taps after suitable treatment. Though water from these sources is available to all the people living in this area but it is not available in sufficient quantity everywhere. There are usually some shortage of water which becomes very severe during hot summer season. Some villages on the outskirts of the city also obtain their water supply directly from the wells.
Exercises, Page 280
Q.1. What changes would you suggest in your home in order to be environment friendly ?
Answer:
- Use energy efficient compact fluorescent lamps (CFLs) instead of traditional filament - type electric bulbs.
- Install solar cell panels to generate as much electricity as possible.
- Use solar cooker to cook food whenever possible.
- Use solar water heater for getting hot water instead of electric geyser.
- Reuse the empty plastic and glass containers for storage purposes in the kitchen, and send the useless papers, plastic, glass and metal objects for recycling.
Q.2. Can you suggest some changes in your school which would make it environment friendly ?
Answer:
- School buses should be run on CNG instead of diesel.
- Rainwater harvesting should be done to recharge ground water.
- Trees should be planted along the school boundary.
- The fallen leaves of trees should be collected and made into compost. This compost can be used in school garden.
- Install solar cell panels to produce electricity.
Q.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 four main stakeholders in the management of forests and wildlife are :
- The local people who live in and around the forest,
- The forest department of the Government,
- The industrialists who use various forest products for their factories, and
- The forest and wild life activists who want to save forests.
The local people who live in and around the forest area should have the authority to decide management of forest produce. This is because the local people are well versed in the practices to use the forest produce in a sustainable manner as they have been using the forest and wildlife resources since the ancient times without causing any damage to the environment.
Q.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) Cutting of trees will not be allowed. The products made from animal skin, fur or ivory will not be used.
(b) Running tap water will not be used for brushing the teeth or taking bath. Water will be taken in a mug and bucket for these purposes to prevent its wastage. Leaking taps will be repaired immediately.
(c) Switch off unnecessary lights and fans, etc., and use bicycle to cover short distances instead of a scooter or car.
Q.5. What can you as an individual do to reduce your consumption of the various natural resources ?
Answer:
- Use energy efficient CFLs instead of filament-type electric bulbs to save electricity (and reduce the consumption of coal)
- Switch off unnecessary lights and fans, and use stairs instead of using lift to save electricity.
- Use solar cooker to cook food whenever possible and solar heater to obtain hot water (so as to reduce the consumption of coal, kerosene or LPG).
- Use bicycle to cover short distances instead of scooter or car to reduce the consumpion of petrol.
- Prevent wastages of water by getting the leaking taps repaired.
Q.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) The five things done by me over the last one week to conserve our natural resources were :
- Replaced all the filament - type bulbs in my house by CFLs.
- Bought a pressure cooker to cook the food to save fuel.
- Cooked rice and pulses (dal) for lunch by using a solar cooker.
- Installed a solar water heater to obtain hot water.
- Went to school by bicycle when I missed the school bus.
(b) The five things done by me over the last one week which increased the pressure on our natural resources were :
- Forgot to switch off light in my room once before going to sleep.
- Did not close the tap while brushing the teeth one day.
- Asked my father to drop me to school on his car one day when I missed the school bus.
- Wasted two big paper sheets while performing a science experiment in the laboratory.
- Threw away a used plastic container which could have been reused to store salt or sugar in the kitchen.
Q.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:
- Walking on foot or riding a bicycle to go to nearby market or other nearby places.
- Using stairs in a building up to at least three floors instead of using a lift.
- Put on an extra sweater on a cold day rather than use a room heater.
- Stop using any products made of animal skin, fur or ivory.
- Switch off the lights, fans, TV, geyser and other electrical appliances when not needed.
- Use compact fluorescent lamps (CFLs) instead of filament - type bulbs.
- Use solar cooker and solar water heater.
- Stop using polythene bags and start using bags made of cloth or jute.
- Recycle products made of paper, plastics, glass and metals.