91. Biosphere reserves differ from national parks and wildlife sanctuaries because in the former

1. 1. Human beings are not allowed to enter

   
   
   

   2. People are an integral part of the system

   
   
   

   3. Plants are paid greater attention than than animals

   
   
   

   4. Living organisms are brought from all over the world and preserved for posterity

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: B

   NA

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92. Which one of the following strongly threatens biodiversity ?

1. 1. Fragile ecosystems such as mangroves and wetlands

   
   
   

   2. Inaccessible habitats in the Himalayas

   
   
   

   3. Destruction of natural habitats and vegetation, and jhum cultivation

   
   
   

   4. Creation of biosphere reserves

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: C

   NA

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93. A molecule of nitrogen which you have just breathed in may have been part of a plant that lived thousands of years ago, or part of a dinosaur that lived millions of years ago. This illustrates the principle that

1. 1. Dead organisms may be fossilized

   
   
   

   2. Molecules of cytoplasm may be replaced by inorganic salts.

   
   
   

   3. Nitrogen does not combine readily with other elements.

   
   
   

   4. Decay bacteria cycle elements.

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: D

   NA

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94. The "greenhouse effect" refers to :

1. 1. Increasing agricultural yields

   
   
   

   2. Gradual warming of the earth's surface

   
   
   

   3. Build-up of toxic airborne pollutants

   
   
   

   4. Reduction in the earth's ozone layer

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: B

   NA

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95. What was the message that the club of Rome were trying to send to the world in 1972 ?

1. 1. Nuclear power is the answer to the world s resource limitations

   
   
   

   2. Global populations will naturally start to decline and therefore the world's problems will begin to subside

   
   
   

   3. Humans were heading on a path to massive environmental degradation and resource exhaustion

   
   
   

   4. None of these

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: C

   NA

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