Long Answer Questions - 5 Marks
Que 1. Prepare a list of five activities that you perform daily in which natural resources can be conserved or energy utilisation can be minimised.
Ans. (i) Unused water in the water bottle may be used for watering plants.
(ii) Close all the taps before you go to sleep.
(iii) Avoid using a hose pipe for watering plants and instead use a mug.
(iv) Wash vehicles only when they are dirty.
(v) Use fan and light only when required.
(vi) Use solar water heating devices.
(vii) Use CFL in place of conventional bulbs/tubes.
Que 2. What is the importance of forest as a resource?
Ans. Forests are renewable resources which
(i) provide habitat, food and protection to wildlife.
(ii) help in balancing CO2 and O2 of atmosphere.
(iii) improve water holding capacity of soil.
(iv) regulate water cycle.
(v) are the source for all essential commodities like fuel wood, timber, pulp and paper, etc., for human beings.
(vi) provide useful products like fruits, resins, gums, essential oils, bidi wrapper, etc.
Que 3. Suggest a few useful ways of utilising waste water.
Ans. Waste water can be used for the following ways:
(i) For recharging the ground water.
(ii) Can be used for irrigation.
(iii) Treated municipal water can be used for washing cars or watering the gardens.
(iv) Certain pollutants in sewage water can become fertiliser for various crops.
Que 4. Explain some harmful effects of agricultural practices on the environment.
Ans. (i) Excessive use of fertilisers changes the chemistry of soil and kills useful microbes.
(ii) Excessive use of non-biodegradable chemical pesticides leads to biological magnification.
(iii) Extensive cropping causes loss of soil fertility.
(iv) Damage to natural ecosystem or habitat.
(v) Excessive use of ground water for agriculture lowers the water table.