Available Answers

1. 1.

   Tick (√) the correct option:

   1. A major air pollutant is
      1. CO
      2. oxides of nitrogen
      3. soot
      4. oxides of sulphur
   2. The undesirable substances or causative agents that are responsible for pollution
      1. iritants
      2. pollutants
      3. excitants
      4. none of the above
   3. Increased concentration of carbon dioxide in atmosphere is responsible for
      1. greenhouse effect
      2. acid rain
      3. lack of photosynthesis
      4. death of aquatic life
   4. Which of the following oxides of nitrogen is not common air pollutant?
      1. NO₂
      2. N₂O
      3. NO
      4. N₂O₃
   5. Taj Mahal may be destroyed by
      1. flood in Yamuna
      2. temperature mediated spoilage of marble
      3. air pollutant from Mathura refinery
      4. all of the above
   6. Sulphur dioxide affects
      1. cell wall
      2. plasmodesmata
      3. all membrane systems
      4. nucleus
   7. Sources of pollution that can be identified are called
      1. point source
      2. non-point source
      3. multiple source
      4. none of the above
   8. Which chemical pollutant inhibits plant activities and restricts plant growth and respiration?
      1. Chlorine
      2. Magnesium
      3. Fluoride
      4. None of the above
2. 2.

   Fill in the blanks:

   1. The most important _____________ source of air pollution is volcanic activity.
   2. Due to the fast spread of industrialisation and advancement of technology, _____________ has become a universal problem.
   3. Filtration allows any _____________ matter to be mechanically or physically removed from water.
   4. Staning of teeth is an indication of _____________ fluorosis.
3. 3.

   Tick (√) the correct and cross (x) the wrong statement:

   1. irrigation water contains dissloved salts.
   2. The microorganisms present in waterbodies play no role in natural cleaning of water.
   3. The cost of purifying polluted water for community use is generally quite low.
   4. Some of the common point sources of contaminants are fertilisers, farmyard manure and compost.
   5. In reverse osmosis, a permeable membrane filter separates the water from contaminants.
4. 4.

   Match the following:

   Column A	Column B
   1. Non-point	a. Rajasthan
   2. Fluorosis	b. Waterworks
   3. Air pollution	c. Adsorption
   4. Ultraviolet irradiation	d. Nitrate concentration
   5. Met-haemoglobin anaemia	e. Indoor pollution

    

5. 5.

   Find the odd one out:

   1. Forest fire, grass fires, pollen grains, water pollution.
   2. Air pollution, industry effluents, excreta, solid waste.
   3. Point source, farmyard manure, NPK, compost.
6. 6.

   Name the process of filtering in which a semi-permeable membrane separates the contaminants from water.