Available Answers

1. 1.

   Write true or false for each statement. Rewrite the false statements correctly.

   1. The layer of air surrounding earth is called the biosphere.
   2. Ozone prevents the entry of ultraviolet rays to the earth.
   3. Thick vegetation is found in deserts.
   4. The transfer of energy from one level to another in food chains increases at each level.
   5. Food chains start with decomposers.
2. 2.

   Fill in the blanks.

   1. We should avoid the use of ___________ articles.
   2. Introduction of unwanted, harmful material into an environment leads to ____________.
   3. __________ and ___________ are the major greenhouse gases.
   4. Enhanced greenhouse effect has caused ____________
   5. ___________ and ____________ have put tremendous pressure on natural resources.
3. 3.

   Tick the most appropriate answer.

   1. The part of the earth which is made up of water is called
      1. biosphere
      2. hydrosphere
      3. atmosphere
      4. lithosphere.
   2. Which of the following group comprises the abiotic components of the environment?
      1. Only plants
      2. Both plants and animals
      3. Air, water and soil
      4. Plants, animals and microorganisms.
   3. Animals depend on plants for
      1. food alone
      2. shelter alone
      3. carbon dioxide
      4. food and oxygen.
   4. The dead and decaying plants and animals are fed upon by
      1. consumers
      2. decomposers
      3. producers
      4. herbivores
   5. Carbon dioxide is a ___________ house gas.
      1. green
      2. blue
      3. red
      4. white
4. 4.

   Fill in the blanks.

   1. ___________ is the outer solid layer of earth covered with soil and rocks.
   2. Plants, animals and microorganisms constitute the __________ components of an environment.
   3. Green plants which make their own food are called _________
   4. ___________ are carnivores that feed on dead animals.
   5. Microorganisms which decompose dead plants and animals are called __________.
5. 5.

   Differentiate between hydrosphere and atmosphere.

6. 6.

   Differentiate between producers and consumers.