NCERT Exemplar Problems
Long Answer Questions
Question 32: Prepare a list of five activities that you perform daily in which natural resources can be conserved or energy utilisation can be minimized.
Answer: Following are five activities in which natural resources can be conserved or energy utilization can be minimized:
|Daily activities||Resource which can be conserved|
|Daily commute to school||Petrol and diesel|
|Eating processed food||Natural resources|
|Using staircase instead of lift||Electricity (coal and petroleum)|
Question 33: In the context of conservation of natural resources, explain the terms reduce, recycle and reuse. From among the materials that we use in daily life, identify two materials for each category.
Answer: Reduce: We should consciously reduce our consumption. We usually buy certain items which we do not really need. For example; we may buy a new toy just out of impulse. We may buy a decorative item to find that there is no place for it in our house. If we reduce our consumption, this helps in reducing the demand from factories. Factories; in turn; would need to produce less. It will help in reducing the drain on natural resources.
Recycle: Many items can be recycled to produce new items. Some types of plastic, paper, metals, glass, etc. can be recycled. We can give old newspaper, metal cans, plastic bottles, glass bottles, etc. to the scrap-dealer. Scrap dealers sell them to recycling factories. Recycling a particular items means there will be less demand for natural resources.
Reuse: Many old items can be reused for different purposes. For example; empty bottles of soft drink can be reused for keeping water in refrigerator. Empty jars of jams and pickles can be used for keeping spices and salt in the kitchen. Empty cans of soft drink can be used as pen stand. Reusing old items helps in reducing the demand for new items. This helps in minimizing the drain on natural resources.
Question 34: Is water conservation necessary? Give reasons.
Answer: It is beyond doubt that conservation of water is necessary. Water is required for all the biological activities. Nearly 70% of out body weight is composed of water. These facts show the importance of water for life.
The earth is endowed with plenty of water. However, most of the water on the earth is saline water which is not suitable for consumption of humans and terrestrial animals and plants. Less than 1% of the total water on the earth is available in the form of potable water. This shows that in spite of plenty of water on the earth, a minuscule amount is available for our use. Thus, it can be said that water is highly precious for us.
Apart from biological functions, water is also required for many activities. We need water for bathing, washing and for doing many other household chores. Water is required by factories for producing goods. Water is required by farmers for irrigation.
While the supply of potable water is limited, its demand is ever increasing due to a growing population.
Question 35: Suggest a few useful ways of utilising waste water.
Answer: Some useful ways of utilizing waste water are as follows:
- Water left from washing the clothes can be used for watering the plants.
- Water left from washing vegetables can be used for cleaning utensils and toilet.
- Water left from washing the clothes can also be used for flushing the toilet.
- Water from outlet of AC can be collected so that it can be used for watering the plants or for mopping the floors.
Question 36: What is the importance of forest as a resource?
Importance of forest as a resource:
- Forests help in maintaining the balance of oxygen and carbon dioxide in the atmosphere.
- Forests contribute a lot towards atmospheric moisture; by way of transpiration. Thus, forests help in bringing rains.
- Trees facilitate recharge of groundwater because roots make the soil porous.
- Trees prevent soil erosion by holding the topsoil in place.
- Many natural resources are obtained from forests, e.g. firewood, lac, catehchu, rubber, timber, medicinal plants, etc.
Question 37: Why are the Arabari forests of Bengal known to be a good example of conserved forest?
Answer: The Arabari forests of Bengal are known to be a good example of conserved forest. The conservation of this forest shows the benefits of involvement of local people in any conservation programme.
This forest range lies in Midnapore district of West Bengal. During the 1970s, this sal forest was in a state of perpetual decline. A visionary forest officer came on the scene. He took the initiative to involve local people in the conservation programme. He gave the responsibility of managing this forest to the local people. In lieu of that, the people were given employment in silviculture and harvesting. They were given 25% share in the final harvest. They were also allowed to collect firewood and fodder; against a nominal fee.
The people cooperated with full vigour as the regained their rights to forest produce. This helped in making a turnaround in the Arabari forest. The proof of this can be gauged from the fact that the once degraded sal forest was valued as Rs. 12.5 crore in 1983.