Environment

1

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
2

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

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

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
4

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%
5

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)
6

Flow of energy in an ecosystem is always

  1. unidirectional
  2. bidirectional
  3. multi directional
  4. no specific direction
7

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
8

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

  1. carnivores
  2. herbivores
  3. decomposers
  4. producers
9

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
10

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

  1. crown
  2. canopy
  3. sapling
  4. humus
11

The coldest region on earth is the

  1. polar region
  2. tropical region
  3. temperate region
  4. coastal region
12

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

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