41) With reference to food chains in ecosystems, consider the following statements:
  1. A food chain illustrates the order in which a chain of organisms feed upon each other.
  2. Food chains are found within the populations of a species.
  3. A food chain illustrates the numbers of each organism which are eaten by others.
Which of the statements given above is / are correct?
  1. 1 only
  2. 1 and 2 only
  3. 1, 2 and 3
  4. None
  

42) Which one of the following terms describes not only the physical space occupied by an organism, but also its functional role in the community of organisms?
  1. Ecotone
  2. Ecological niche
  3. Habitat
  4. Home range
  

43) With reference to the food chains in ecosystems, which of the following kinds of organism is / are known as decomposer organism/organisms?
  1. Virus
  2. Fungi
  3. Bacteria
Select the correct answer using the codes given below.
  1. 1 only
  2. 2 and 3 only
  3. 1 and 3 only
  4. 1, 2 and 3      


44) Consider the following fauna of India:
  1. Gharial
  2. Leatherback turtle
  3. Swamp deer
Which of the above is/are endangered?
  1. 1 and 2 only
  2. 3 only
  3. 1, 2 and 3
  4. None 


45) Consider the following
  1. Star tortoise
  2. Monitor lizard
  3. Pygmy hog
  4. Spider monkey
Which of the above found in India?
  1. 1, 2 and 3 only
  2. 2 and 3 only
  3. 1 and 4 only
  4. 1, 2, 3 and 4


46) Consider the following organisms
  1. Agaricus
  2. Nostoc
  3. Spirogyra
Which of the above is / are used as biofertilizer / biofertilizers
  1. 1 and 2
  2. 2 only
  3. 2 and 3
  4. 3 only


47) Which of the following adds / add nitrogen to the soil?
  1. Excretion of urea by animals
  2. Burning of coal by man
  3. Death of vegetation
Select the correct answer using the codes given below.
  1. 1 only
  2. 2 and 3 only
  3. 1 and 3 only
  4. 1, 2 and 3

48) Photochemical smog is a resultant of the reaction among
  1. NO2, 03 and peroxyacetyl nitrate in the presence of sunlight
  2. CO, 02 and peroxyacetyl nitrate in the presence of sunlight
  3. CO, CO2 and N02 at low temperature
  4. High concentration of N02, O3 and CO in the evening
  

49) Recombinant DNA technology (Genetic Engineering) allows genes to be transferred
  1. across different species of plants
  2. from animals to plants
  3. from microorganisms to higher organisms
Select the correct answer using the codes given below.
  1. 1 only
  2. 2 and 3 only
  3. 1 and 3 only
  4. 1, 2 and 3



50) With reference to the usefulness of the by-products of sugar industry, which of the following statements is / are correct?
  1. Bagasse can be used as biomass fuel for the generation of energy.
  2. Molasses can be used as one of the feed stocks for the production of synthetic chemical fertilizers.
  3. Molasses can be used for the production of ethanol.
Select the correct answer using the codes given below.
  1. 1 only
  2. 2 and 3 only
  3. 1 and 3 only
  4. 1, 2 and 3