The poisonous nature of carbon monoxide (CO) is due to its

  1. insolubility in water
  2. ability to form a complex with haemoglobin
  3. ability to reduce some metal oxides
  4. property of having one sigma bond

Which one of the following is a cause of acid rains?

  1. Ozone
  2. Ammonia
  3. Sulphur dioxide
  4. Carbon monoxide

Which one of the following gases is placed second in respect of abundance in the Earth's atmosphere?

  1. Oxygen
  2. Hydrogen
  3. Nitrogen
  4. Carbon dioxide

The percentage of solar radiation absorbed by all the green plants for the process of photosynthesis is about

  1. 1%
  2. 5%
  3. 8%
  4. 10%

Which group of organisms are not constituents of a food chain?

  1. Grass, lion, rabbit, wolf
  2. Plankton, man, fish, grasshopper
  3. Wolf, grass, snake, tiger
  4. Frog, snake, eagle, grass, grasshopper

Select the correct option:

  1. (i) and (iii)
  2. (iii) and (iv)
  3. (ii) and (iii)
  4. (i) and (iv)

Flow of energy in an ecosystem is always

  1. unidirectional
  2. bidirectional
  3. multi directional
  4. no specific direction

In the given food chain, suppose the amount of energy at fourth trophic level is 5 kJ, what will be the energy available at the producer level?
Grass → Grasshopper → Frog → Snake → Hawk

  1. 5 kJ
  2. 50 kJ
  3. 500 kJ
  4. 5000 kJ

In a food chain, the third trophic level is always occupied by

  1. carnivores
  2. herbivores
  3. decomposers
  4. producers

The process of nitrogen-fixation by bacteria does not take place in the presence of

  1. molecular form of hydrogen
  2. elemental form of oxygen
  3. water
  4. elemental form of nitrogen

The branchy part of a tree above the stem is known as

  1. crown
  2. canopy
  3. sapling
  4. humus

The coldest region on earth is the

  1. polar region
  2. tropical region
  3. temperate region
  4. coastal region

The method of preparing compost with the help of earthworms is called

  1. composting
  2. vermicomposting
  3. manuring
  4. decomposing