Olympiad – Class X – Science - Bio - Our Environment

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Question - 1

Which of the following gases destroys the ozone layer?

  • A CFC
  • B CO2
  • C SO2
  • D NH3

Question - 2

Which of the following represents herbivores in an ecosystem?

  • A Secondary consumers
  • B Primary consumers
  • C Producers
  • D Decomposers

Question - 3

Which of the following represents trophic levels in an ecosystem?

  • A Water level
  • B Energy level
  • C Salt level
  • D Oxygen level

Question - 4

Which of the following represents energy flow in an ecosystem?

  • A Multidirectional
  • B Unidirectional
  • C Bidirectional
  • D Circular

Question - 5

First link in any food chain is usually green plants. Which of the following statements gives the correct explanation about the above statement?

  • A Only green plants have the capacity to synthesise food using sunlight.
  • B There are more herbivores than carnivores in a food chain.
  • C Green plants are the only ones fixed at one place in the soil and do not show any kind of movements.
  • D Green plants are widely distributed

Question - 6

Which of the following is the logical sequence of a food chain?

  • A Producer \(\rightarrow\) consumer \(\rightarrow\) decomposer
  • B Decomposer \(\rightarrow\) consumer\(\rightarrow\)producer
  • C Producer \(\rightarrow\) decomposer \(\rightarrow\) consumer
  • D Consumer \(\rightarrow\) producer \(\rightarrow\) decomposer

Question - 7

Trophic levels are formed by which of the following components?

  • A Only plants
  • B Only animals
  • C Only carnivores
  • D Organisms linked in food chain

Question - 8

Which of the following represents 'X' in the given figure?

  • A Air pollutant
  • B Smog
  • C Acid rain
  • D Salts

Question - 9

Which of the following organisms are secondary consumers in any food web?

  • A Only green plants
  • B Green plants, rabbits and rats
  • C Frogs, snakes and eagles
  • D Frogs, snakes and rabbits

Question - 10

Which of the following layers constitutes biosphere?

  • A Hydrosphere
  • B Lithosphere
  • C Atmosphere
  • D All of the above