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Ecosystem: Class-XII


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MCQs on Ecosystem: Class-XII for NEET Practice


Identify the correct statements:
A. Detrivores perform fragmentation.
B. The humus is further degraded by some microbes during mineralization.
C. Water soluble inorganic nutrients go down into the soil and get precipitated by a process called leaching.
D. The detritus food chain begins with living organisms.
E. Earthworms break down detritus into smaller particles by a process called catabolism.

NEET-2023 [Ecosystem] [class-xii ]

  • D, E, A only
  • A, B, C only
  • B, C, D only
  • C, D, E only
  • Correct Option: B  [ A, B, C only ]

    Remark:

In the equation GPP – R = NPP
GPP is Gross Primary Productivity
NPP is Net Primary Productivity.

R here is:

NEET-2023 [Ecosystem] [class-xii ]

  • Reproductive allocation
  • Photosynthetically active radiation
  • Respiratory quotient
  • Respiratory loss
  • Correct Option: D  [ Respiratory loss ]

    Remark:

Given below are two statements:
Statement I: Decomposition is a process in which the detritus is degraded into simpler substances by microbes.
Statement II: Decomposition is faster if the detritus is rich in lignin and chitin.
In the light of the above statements, choose the correct answer from the options given below:

NEET-2022 [Ecosystem] [class-xii ]

  • Both Statement I and Statement II are correct
  • Both Statement I and Statement II are incorrect
  • Statement I is correct but Statement II is incorrect
  • Statement I is incorrect but Statement II is correct
  • Correct Option: C  [ Statement I is correct but Statement II is incorrect ]

    Remark:

Which one of the following will accelerate phosphorus cycle?

NEET-2022 [Ecosystem] [class-xii ]

  • Burning of fossil fuels
  • Volcanic activity
  • Weathering of rocks
  • Rain fall and storms
  • Correct Option: C  [ Weathering of rocks ]

    Remark:

Detritivores breakdown detritus into smaller particles. This process is called:

NEET-2022 [Ecosystem] [class-xii ]

  • Fragmentation
  • Humification
  • Decomposition
  • Catabolism
  • Correct Option: A  [ Fragmentation ]

    Remark:

The amount of nutrients, such as carbon, nitrogen, phosphorus and calcium present in the soil at any given time, is referred as:

NEET-2021 [Ecosystem] [class-xii ]

  • Climax
  • Climax community
  • Standing state
  • Standing crop
  • Correct Option: C  [ Standing state ]

    Remark:

Which of the following statements is not correct?

NEET-2021 [Ecosystem] [class-xii ]

  • Pyramid of biomass in sea is generally inverted.
  • Pyramid of biomass in sea is generally upright.
  • Pyramid of energy is always upright.
  • Pyramid of numbers in a grassland ecosystem is upright.
  • Correct Option: B  [ Pyramid of biomass in sea is generally upright. ]

    Remark:

In the equation GPP–R = NPP.
R represents:

NEET-2021 [Ecosystem] [class-xii ]

  • Radiant energy
  • Retardation factor
  • Environment factor
  • Respiration losses
  • Correct Option: D  [ Respiration losses ]

    Remark:

Match the trophic levels with their correct species examples in grassland ecosystem.

(A)Fourth trophic level (I)Crow
(B)Second trophic level (II)Vulture
(C)First trophic level (III)Rabbit
(D)Third trophic level (IV)Grass

NEET-(Sept)2020 [Ecosystem] [class-xii ]

  • (A)-(II), (B)-(III), (C)-(IV), (D)-(I)
  • (A)-(III), (B)-(II), (C)-(I), (D)-(IV)
  • (A)-(IV), (B)-(III), (C)-(II), (D)-(I)
  • (A)-(I), (B)-(II), (C)-(III), (D)-(IV)
  • Correct Option: A  [ (A)-(II), (B)-(III), (C)-(IV), (D)-(I) ]

    Remark:

In relation to Gross primary productivity and Net primary productivity of an ecosystem, which one of the following statements is correct?

NEET-(Sept)2020 [Ecosystem] [class-xii ]

  • Gross primary productivity is always less than net primary productivity.
  • Gross primary productivity is always more than net primary productivity.
  • Gross primary productivity and Net primary productivity are one and same.
  • There is no relationship between Gross primary productivity and Net primary productivity.
  • Correct Option: B  [ Gross primary productivity is always more than net primary productivity. ]

    Remark: