NEET Biology MCQs Ecosystem [Free PDF Download]

NEET Biology MCQs Ecosystem

1. Which ecosystem has the highest gross primary productivity
   a) Rainforests b) Coral reefs c) Mangroves d) Grass lands
2. In primary succession in water, the pioneer species are
   a) Free floating angiosperm b) Small phytoplanktons
   c) Rooted hydrophytes d) Lichens
3. The pyramid of biomass will be inverted in the ecosystem of
   a) Forests b) Ponds c) Grasslands d) Drylands
4. Complete the following model of carbon cycle filling 𝐴,𝐵,𝐶,𝐷,𝐸 and 𝐹 a) A-Osmosis, B-Photosynthesis, C-Respiration, D-Burning of fuel wood, E-Forest food chain, F-Limestone
   b) A-Photorespiration, B-Respiration, C-Respiration, D-Burning of organic debris, E-Pond food chain, F
   Dolomite
   c) A-Respiration, B-Photosynthesis, C-Respiration, D-Combustion of fossil fuels, E-Aquatic food chain, F
   Coal, oil
   d) A-Respiration, B-Photosynthesis, C-Respiration, D-Burning of forest, E-Terrestrial food chain, F-Forest
5. Large unit of land having different types of plants and animals, is called
   a) Uniform vegetation b) Biome c) Ecosystem d) Niche
6. Which of the following is known as the sedimentary cycle because its reservoir is a sedimentary rock?
   a) Carbon cycle b) Hydrologic cycle c) Nitrogen cycle d) Phosphorus cycle
7. In ecological succession the communities in near equilibrium with the environment, are called
   a) Climax communities b) Ecofriendly communities
   c) Seral communities d) Pioneer communities
8. Dried plant parts such as leaves, bark, flowers, etc., and dead remains of animals including faecal matter,
   drop over the soil, constitute
   I. below ground detritus
   II. above ground detritus
   III. litter fall
   Choose the correct option
   a) I and II b) I and IV c) II and III d) I and III
9. In the following, there is no difference.
   a) Trophic level-I and herbivores b) Primary consumers and herbivores
   c) Primary carnivores and trophic level-II d) Secondary consumer and herbivores
10. Consider the following statements about carbon cycle
    I. Carbon is released into the atmosphere
    II. The atmospheric input of carbon from rainfall is greater

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III. Carbon gas is exchanged between organisms and atmosphere during respiration
Which of the statement given above are correct?
a) I and II b) I and III c) II and III d) I, II and III

11. Ecological pyramids were discovered by
    a) Elton b) Odum c) Reiter d) None of these
12. Plant successions occurring in a sandy area is
    a) Psammosere b) Hydrosere c) Xerosere d) Lithosere
13. An ecosystem is
    a) Different communities of plants, animals and microbes interact together with their physico-chemical
    environments
    b) Different communities of plants and microbes interact with their physico-chemical environments
    c) A localised assemblage of several plants and animals
    d) An assemblage of plants, animals and their surroundings
14. What do ecologists call the transfer of energy that begins with the sun and passes from one organism to
    the next in a food chain?
    a) A food web b) A top consumer
    c) Energy flow d) A pyramid of number
15. The energy invested in the production of new tissue by autotrophic organisms is termed
    a) Gross primary production b) Decomposition
    c) Gross photosynthetic activity d) Net primary production
16. Microbes that breakdown the complex organic matter into simple substances like carbon, nitrogen, water,
    etc., are
    a) Producers b) Decomposers c) Consumers d) Symbionts
17. Which one of the following is no used for construction of ecological pyramids?
    a) Dry weight b) Number of individuals
    c) Rate of energy flow d) Fresh weight
18. Which element is formed by the weathering of rocks and absorbed by plant from the soil?
    a) Phosphorus b) Carbon c) Nitrogen d) Oxygen
19. Given diagram represents a pyramid of biomass in an aquatic system

Identifies 𝐴 of 𝐵 and select correct options
a) A is phytoplanktons and B is zooplanktons b) A is zooplanktons and B is phytoplanktons
c) A is smally body animals d) B is small body animals

20. Given below is one of the types of ecological pyramids

This type represents
a) Pyramid of number in a grassland ecosystem b) Pyramid of energy in forest ecosystem
c) Pyramid of biomass in sea ecosystem d) Pyramid of biomass in terrestrial ecosystem

21. The process of breaking down complex organic matter into inorganic substances like CO2, water and
    nutrient is called
    a) Humification b) Mineralisation c) Decomposition d) Leaching
22. Series of changes in structure and comparition of communities on previously barren area is

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a) Sere b) Climax community c) Primary succession d) Secondary succession

23. Energy transferred from on trophic level to another is
    a) 5% b) 10% c) 15% d) 20%
24. When the two ecosystems overlap each other, the areas is called
    a) Habitat b) Niche c) Ecotone d) Ecotype
25. The total amount of nutrients like carbon, phosphorus, calcium, etc., present in soil at any time is called
    a) Standing crop b) Standing state c) Nutrient crops d) Sediment
26. A food web is more realistic than a food chain for showing the feeding relationships in an ecosystem
    because
    a) It compares the number of consumers to the number of microorganisms in an ecosystem
    b) Food chains use only a small sampling of organisms
    c) A food web explains why there are more producers than consumers
    d) Producers are usually eaten by many different consumers and most consumers are eaten by more than
    one predator
27. Identify 𝐴,𝐵 and 𝐶 from the given flow chart a) A-Bulbul, B-Snake, C-Monkey b) A-Beetle, B-Lizard, C-Praying mantis
    c) A-Ladybird, B-Snake, C-Hawk d) A-Lizard, B-Bird, C-Snake
28. Which of the following ecological pyramid are always inverted?
    a) Pyramid of number in parasific food chain and pyramid of biomass in pond ecosystem
    b) Pyramid of number in pond ecosystem and pyramid of biomass in pond ecosystem
    c) Pyramid of number in pasific food chain and pyramid of number in pond ecosystem
    d) All of the above
29. An individual transitional communities in ecological succession are termed as
    a) Climax community b) Pioneer community c) Seral communities d) Single community
30. The living organisms present in an ecosystem forms
    a) Abiotic components b) Biotic components
    c) Physical components d) Chemical components
31. The rate of biomass production per unit area over a time period by plants during photosynthesis is called
    a) Gross primary productivity b) Net primary productivity
    c) Secondary productivity d) Decomposition
32. The decomposition rate is higher when detritus is rich in
    a) Nitrogen and sugar b) Phosphorus and sugar
    c) Calcium and sugar d) Both (b) and (c)
33. A man-made ecosystem is
    a) Less in diversity b) More in diversity
    c) Man does not make ecosystem d) More stable than natural ecosystem
34. The green plants in an ecosystem which can trap solar energy to convert it into chemical bond energy are
    called
    a) Producer b) Decomposer c) Consumer d) Predators
35. Vegetable eating person acts as
    a) primary producer b) primary consumer c) secondary consumer d) tertiary consumer
36. Consider the following statements about food chain
    I. The transfer of energy from producers to top consumers through a series of organisms is called food
    chain
    II. A food chain is always straight and proceeds in a progressive straight line

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III. In a food chain, there is unidirectional flow of energy from sun to producers and subsequently to series
of different types of consumers
Which of the statements given above are correct?
a) I and II b) I and III c) II and III d) I, II and III

37. Food chain consists of
    a) Plants b) Herbivores c) Carnivores d) All of these
38. Consider the following ecosystem
    I. Pond ecosystem II. Terrestrial ecosystem
    III. Oceans ecosystem IV. Forest ecosystem
    There are mainly three food chain in natural ecosystem’s grazing food chain, detritus food chain, parasite
    food chain
    Find out which of the following will have grazing food chain?
    a) Pond ecosystem b) Terrestrial ecosystem c) Ocean ecosystem d) All of these
39. A much large fraction of energy flows in aquatic ecosystem through
    a) grazing food chain b) Detritus food chain c) Complex food chain d) Food web
40. Consider the following statements concerning food chains.
    I. Removal of 80% tigers from an area resulted in greatly increased growth of vegetation.
    II. Removal of most of the carnivores resulted in an increased population of deers.
    III. The length of food chains is generally limited to 3 to 4 trophic levels due to energy loss.
    IV. The length of food chains may vary from 2 to 8 trophic levels.
    Which two of the above statements are correct?
    a) II and III b) III and IV c) I and IV d) I and II
41. Consider the following statements about food web
    I. One organism hold more than one position
    II. The flow of energy is very difficult to calculate
    III. Instead of straight line it is a series of branching lines
    IV. Competition is amongst the members of same and different trophic levels
    Which of the statements given above are correct?
    a) I, II and III b) I, III and IV c) II, III and IV d) I, II, III and IV
42. The statement, ‘Tiger is in the apex of food chain’, indicates
    a) Tiger has many enemies
    b) Tiger has maximum biomass
    c) Tiger is omnivorous
    d) Tiger is dependent upon large number of herbivores and even more number of trees in forest
43. Simplified model of phosphorus cycling in a terrestrial ecosystem is given below. Identify 𝐴,𝐵,𝐶 and 𝐷 a) A-Weathering, B-Decomposition, C-Consumer, D-Soil
    b) A-Decomposition, B-Weathering, C-Producer, D-Soil
    c) A-Weathering, B-Decomposition, C-Decomposer, D-Soil
    d) A-Decomposition, B-Decomposer, C-Weathering, D-Soil
44. Primary productivity is affected by
    I. temperature
    II. sunlight
    III. moisture

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IV. availability of nutrients
a) I and II b) I, II and III c) II, III and IV d) I, II, III and IV

45. Terai forest is
    a) Tropical forest b) Coniferous forest
    c) Deciduous forest d) Temperate deciduous forest
46. The figure given below is a diagrammatic representation of response of organisms to abiotic factors. What
    do A, B and C represent respectively? A B C a) Conformer Regulator Partial regulator
    b) Regulator Partial regulator Conformer
    c) Partial Regulator Regulator Conformer
    d) Regulator Conformer Partial regulator
47. The ecological niche of population is a
    a) Geographical area that it covers b) Place where it lives
    c) Set of conditions and resource it uses d) None of the above
48. Inverted pyramid is found in
    a) Biomass pyramid of aquatic system b) Energy pyramid of grassland
    c) Biomass pyramid of grassland d) Pyramid of number of aquatic system
49. If a predator is overexploits its prey in a ecosystem then what might be consequences of this?
    a) Prey might be extinct b) Predator might be extinct
    c) Both (a) and (b) d) No affect on prey and predator
50. Which of the following organisms form the decomposers?
    a) Pteris b) Bacteria c) Saprophytic fungi d) Both (b) and (c)
51. Osmotrophs belong to
    a) Primary consumers b) Secondary consumers c) Top carnivores d) Decomposers
52. Greater primary productivity depends upon
    a) Rain (humidity) b) Availability of nutrients
    c) Both (a) and (b) d) None of these
53. Word detritus includes
    a) Dead plant parts b) Remains of animals c) Animal excretions d) All of these
54. Decomposition of organic matter is brought about by
    a) Protozoa b) Plants c) Microorganisms d) None of these
55. Some of the stages in the hydrarch are labelled as
    I. Marsh meadow stage
    II. Reed swamp stage
    III. Submerged plant stage
    IV. Phytoplankton stage
    V. Submerged free floating plant stage
    Identify the choice that represents the correct sequence of these stages
    a) IV, III, V, II and I b) III, V, I, II and IV c) II, IV, III, I and V d) IV, V, III, II and I
56. The correct sequence of food chain is

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a) Grass → insect → bird → snake b) Grass → bird → insect → snake
c) Snake → bird → insect → grass d) Grass → snake → bird → insect

57. When the number of organisms at successive levels are plotted they assume the shape of a pyramid. This
    is called the pyramid of
    a) Biomass b) Number c) Energy d) None of these
58. Which kind of pyramid is represented by the given diagram a) Pyramid of number in tree ecosystem b) Pyramid of biomass in tree ecosystem
    c) Pyramid of biomass in aquatic ecosystem d) Pyramid of energy in tree ecosystem
59. In ecotone, some species become abundant called
    a) Sibling species b) Endemic species c) Rare species d) Edge species
60. Ecosystem may be defined as
    a) A species along with environment b) Plants found in water
    c) Plants found on land d) All plants and animal species along with their
    environment
61. Following are the different stages in primary succession in water

Which of the following is the logical sequence of primary succession in water?
a) II → IV → V → VII → I → III → V b) I → III → V → II → IV → VI → VII
c) V → II → IV → VI → VII → III → I d) VI → VII → III → I → V → II → IV

62. Energy flow and energy transformation in living systems strictly conform to the
    a) Law of limiting factors b) Liebig’s law of minimum
    c) Law’s of thermodynamics d) Shelford’s law of tolerance
63. Phosphorus is required for making
    I. shell
    II. bones
    III. teeth
    Choose the correct option
    a) I and II b) I and III c) II and III d) I, II and III
64. The species that invade a bare area in ecological succession are called
    a) Benthos b) Biological species c) Seral species d) Pioneer species
65. In a pond ecosystem, benthos means
    a) Primary consumers in the depth of a pond b) Virus
    c) Zooplankton on the water surface d) Bacteria
66. The given figure best represents

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a) Pyramid of number in parasitic food chain b) Pyramid of biomass in forest ecosystem
c) Pyramid of number in grassland ecosystem d) Pyramid of number in forest ecosystem

67. Decomposers are
    a) Autotrophs b) Autoheterotrophs c) Organotrophs d) Heterotrophs
68. The lentic ecosystem includes
    a) Gravitational water b) Standing water c) Rain water d) Running water
69. Primary succession on rocks starts with
    a) Lichen b) Grass c) Mosses d) Ferns
70. Energy storage at consumer level is called
    a) Gross primary productivity b) Secondary productivity
    c) Net primary productivity d) Net productivity
71. True/False
    I. The total organic matter synthesised by the producers in the process of photosynthesis per unit time and
    area is known as gross primary productivity
    II. Net primary productivity is the weight of the organic matter stored by the producers in a unit
    area/volume per unit time
    a) I is true while II is false b) II is true, while I is false
    c) I and II are true d) I and II are false
72. Lion is kept under in Eltonian pyramid as
    a) Producer b) Primary consumer c) Secondary consumer d) Tertiary consumer
73. Maximum primary productivity of pond is achieved by
    a) Phytoplankton b) Zooplankton c) Floating plants d) Red algae
74. What is the medium by which carbon cycle takes place?
    a) Through atmosphere b) Through ocean
    c) Through living and dead organisms d) All of the above
75. …… temperature is required for the proper functioning of an enzyme. The most appropriate word
    a) Low b) High c) Optimum d) None of the above
76. In ecological pyramid the base always represent the …A… and the apex represents …B… Here A and B
    represents
    a) A-producers; B-top level consumers b) A-top level consumer; B-producers
    c) A-producers; B-secondary consumers d) A-producers; B-primary consumers
77. Maximum net productivity in the terrestrial ecosystem is in
    a) Rain forest b) Deciduous forest
    c) Mangrove plantation d) Both (a) and (b)
78. The primary consumers in a pond ecosystem are
    a) Phytoplankton b) Zooplankton c) Fishes d) Bacteria
79. Which of the following factor is contributing to an overload of the carbon cycle?
    a) Photosynthesis b) Cellular respiration c) Deforestation d) Aforestation
80. Which ones are the reservoirs of sulphur and carbon cycles respectively?
    a) Atmosphere and consumers b) Earth crust and atmosphere
    c) Earth crust and producer d) Atmosphere and predator

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