Here you will find NEET MCQ questions on the Class 12 Biology Chapter “Ecosystem” based on the NCERT textbook. Solve the below free NEET mock test for a better understanding of the various topics. 100+ important MCQs (multiple choice questions) are given in this NEET question bank.
“Ecosystem” is the 14th chapter in the unit “Ecology” of class XII or class 12th Biology NCERT. Do note that NEET (which is conducted by NTA) is based on NCERT books so they are a must have. You can also download PDF of NCERT textbooks.
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1. A pond is?
(a) A biome
(b) A community of plants and animals
(c) A natural ecosystem
(d) None of the above
(c) A natural ecosystem
2. Which one statement is correct regarding man-made ecosystems?
(a) They are highly efficient
(b) They are poor in diversity
(c) They are vulnerable to drought, floods and diseases
(d) All are correct
(d) All are correct
3. The largest ecosystem in the world is?
(a) Forests
(b) Grasslands
(c) Great lakes
(d) Oceans
(d) Oceans
4. A natural ecosystem
(a) Depends on the man
(b) Depends on plants
(c) Depends on animals
(d) Is auto operated
(d) Is auto operated
5. Which of the following is an artificial ecosystem created by humans?
(a) Grassland ecosystem
(b) Agroecosystem
(c) Ecosystem of artificial lakes and dams
(d) Forest ecosystem
(b) Agroecosystem
6. Peacocks eat snakes that eat frogs. Frogs, in turn, eat the leaves of the plants. The peacock is?
(a) primary consumer
(b) secondary consumer
(c) decomposer
(d) the apex of the food pyramid
(d) the apex of the food pyramid
7. Ecosystems are
(a) Always open
(b) Always closed
(c) Both open and closed depending upon the community
(d) Both open and closed depending upon biomass
(c) Both open and closed depending upon the community
8. Biotic components of an ecosystem include?
(a) Producers, consumers and decomposers
(b) Producers and consumers
(c) Producers only
(d) Consumers only
(a) Producers, consumers and decomposers
9. What is the annual net primary productivity of the entire biosphere?
(a) 170 billion tons (dry weight) of organic matter
(b) 165 billion tons (dry weight) of organic matter
(c) 160 billion tons (dry weight) of organic matter
(d) 155 billion tons (dry weight) of organic matter
(a) 170 billion tons (dry weight) of organic matter
10. Which factor limits the primary productivity of an ecosystem most often?
(a) Solar radiation/light
(b) Oxygen
(c) Consumers
(d) Nitrogen
(a) Solar radiation/light
11. The type of vegetation that occurs in an area with low rainfall, high temperatures, and loose and sandy soil is called what?
(a) grassland
(b) scrub forest
(c) xerophytic
(d) evergreen tropical forest
(c) xerophytic
12. Ecosystems resist change because they are in a state of?
(a) Imbalance
(b) Homeostasis
(c) Shortage of components
(d) Deficiency of light
(b) Homeostasis
13. What are the two components of an ecosystem?
(a) Plants and animals
(b) Weeds and trees
(c) Biotic and abiotic
(d) Frog and men
(c) Biotic and abiotic
14. Which of the following is the most stable ecosystem?
(a) Mountain
(b) Desert
(c) Forest
(d) Ocean
(d) Ocean
15. Energy storage at the consumer level is called?
(a) Gross primary productivity
(b) Secondary productivity
(c) Net primary productivity
(d) Net productivity
(b) Secondary productivity
16. Primary productivity
(a) is equal to the standing crop of an ecosystem.
(b) is greatest in freshwater ecosystems.
(c) is the rate of conversion of light to chemical energy in an ecosystem.
(d) is inverted in some aquatic ecosystems.
(c) is the rate of conversion of light to chemical energy in an ecosystem.
17. Energy flow in an ecosystem is?
(a) unidirectional
(b) bidirectional
(c) multidirectional
(d) All of these
(a) unidirectional
18. Which one is nature’s cleaner?
(a) Consumers
(b) Producers
(c) Decomposers and scavengers
(d) Symbionts
(c) Decomposers and scavengers
19. Who is referred to as the farmer’s friend?
(a) Ant
(b) Sparrow
(c) Earthworm
(d) Rabbit
(c) Earthworm
20. Which of the following statements is true?
(a) Decomposition rate is slower if detritus is rich in lignin and chitin, and quicker if detritus is rich in nitrogen and water-soluble substances like sugars.
(b) Decomposition rate is slower if detritus is rich in nitrogen and water-soluble substances like sugars, and quicker if detritus is rich in lignin and chitin.
(c) Decomposition rate is slower if detritus is rich in cellulose, and quicker if detritus is rich in phosphorus.
(d) Decomposition rate is quicker if detritus is rich in lignin, and quicker if detritus is rich in sulphur.
(a) Decomposition rate is slower if detritus is rich in lignin and chitin, and quicker if detritus is rich in nitrogen and water-soluble substances like sugars.
21. What are the two most important climatic factors that regulate decomposition through their effects on soil microbes?
(a) Temperature and rainfall
(b) Temperature and soil – moisture
(c) Temperature and humidity
(d) Temperature and pressure
(b) Temperature and soil – moisture
22. Which one of the following statements is correct?
(a) Warm and moist environment favour decomposition whereas low temperature and anaerobiosis inhibit decomposition
(b) Warm and moist environment inhibit decomposition whereas low temperature and anaerobiosis favour decomposition
(c) Warm and anaerobiosis favour decomposition whereas low temperature favours decomposition
(d) Warm and low temperatures inhibit decomposition whereas anaerobiosis favours decomposition
(a) Warm and moist environment favour decomposition whereas low temperature and anaerobiosis inhibit decomposition
23. Which of the following process helps in nutrient conservation?
(a) Mineralisation
(b) Immobilisation
(c) Leaching
(d) Nitrification
(b) Immobilisation
24. What percentage of the PAR is captured by the plants?
(a) 5 – 10%
(b) 7 – 10%
(c) 8 – 10%
(d) 2 – 10%
(d) 2 – 10%
25. Each trophic level has a certain mass of living material at a particular time is known as?
(a) catabolism
(b) standing crop
(c) humification
(d) primary productivity
(b) standing crop
26. In a forest ecosystem, bacteria and fungi are generally?
(a) Producers
(b) Decomposers
(c) Primary consumers
(d) Secondary consumers
(b) Decomposers
27. What will happen if decomposers are removed from the ecosystem?
(a) Energy cycle is stopped
(b) Mineral cycle is stopped
(c) Consumers cannot absorb solar energy
(d) Rate of decomposition of mineral increases
(b) Mineral cycle is stopped
28. Ecosystem is?
(a) always open
(b) always closed
(c) both open and closed depending upon the community
(d) both open and closed depending upon biomass
(a) always open
29. Bamboo plant is growing in a fir forest then what will be the trophic level of it?
(a) First trophic level (T1)
(b) Second trophic level (T2)
(c) Third trophic level (T3)
(d) Fourth trophic level (T4)
(a) First trophic level (T1)
30. An ecosystem that can be easily damaged but can recover after some time if the damaging effect stops will be having?
(a) low stability and high resilience
(b) high stability and low resilience
(c) low stability and low resilience
(d) high stability and high resilience
(a) low stability and high resilience
31. Which one of the following ecosystem types has the highest annual net primary productivity?
(a) Tropical deciduous forest
(b) Temperate evergreen forest
(c) Temperate deciduous forest
(d) Tropical rain forest
(d) Tropical rain forest
32. The slow rate of decomposition of fallen logs in nature is due to theirs?
(a) low moisture content
(b) poor nitrogen content
(c) the anaerobic environment around them
(d) low cellulose content
(d) low cellulose content
33. Mass of living matter at a trophic level in an area at any time is called?
(a) standing crop
(b) detritus
(c) humus
(d) standing state
(a) standing crop
34. Which one of the following animals may occupy more than one trophic level in the same ecosystem at the same time?
(a) Sparrow
(b) Lion
(c) Goat
(d) Frog
(a) Sparrow
35. Which one of the following is not a gaseous biogeochemical cycle in an ecosystem?
(a) Sulphur cycle
(b) Phosphorus cycle
(c) Nitrogen cycle
(d) Carbon cycle
(b) Phosphorus cycle
36. In the grass-deer-tiger food chain, grass biomass is one tonne. The tiger biomass shall be?
(a) 100 kg
(b) 10 kg
(c) 200 kg
(d) 1 kg
(b) 10 kg
37. Which one of the following is a primary consumer in the maize field ecosystem?
(a) Lion
(b) Grasshopper
(c) Wolf
(d) Phytoplankton
(b) Grasshopper
38. Whale is?
(a) Primary producer
(b) Carnivorous secondary consumer
(c) A decomposer
(d) Herbivorous
(b) Carnivorous secondary consumer
39. If an ecosystem is composed of only three trophic levels then how much energy will be conserved at the III trophic level?
(a) 30%
(b) 20%
(c) 10%
(d) 1%
(d) 1%
40. The animals that occupy the same trophic level are?
(a) Lion & Bees
(b) Deer & Bees
(c) Snakes & Earthworm
(d) Crow & Cow
(d) Crow & Cow
41. What are the organisms that are used as food materials but that are not killed by other organisms in nature?
(a) Primary consumer
(b) Secondary consumer
(c) Top consumer
(d) Decomposers
(a) Primary consumer
42. What type of pyramid shows the best efficiency of an ecosystem?
(a) Pyramid of number
(b) Pyramid of biomass
(c) Pyramid of volume
(d) Pyramid of energy
(b) Pyramid of biomass
43. Decomposers of an ecosystem include?
(a) microscopic animals
(b) bacteria and fungi
(c) Both (a) and (b)
(d) Bacteria, fungi and microscopic animals
(b) bacteria and fungi
44. In a simple ecosystem with grass, deer and tiger in the food chain, how much amount of food is available to the tiger if the grass production is one tonne?
(a) 100 kg
(b) 10 kg
(c) 1 kg
(d) 100 gm
(b) 10 kg
45. Which type of pyramid of number is present in the tree ecosystem?
(a) Upright
(b) Inverted
(c) Rhomboidal
(d) Both (a) and (b)
(b) Inverted
46. What type of pyramid shows a standing crop ecosystem?
(a) Pyramid of energy
(b) Pyramid of number
(c) Pyramid of biomass
(d) None of above
(c) Pyramid of biomass
47. What is the role of producers in an ecosystem?
(a) To convert organic compound into an inorganic form
(b) To utilize chemical energy
(c) To trap solar energy and convert it into chemical energy
(d) To release energy
(c) To trap solar energy and convert it into chemical energy
48. A food chain can have trophic levels-
(a) Three or four
(b) Three
(c) Two
(d) One
(a) Three or four
49. Where do herbivores/deer fit into a food chain?
(a) Primary producers
(b) Primary consumers
(c) Secondary consumers
(d) Decomposers
(b) Primary consumers
50. Grassland with scattered trees is called?
(a) savannah
(b) deciduous forest
(c) evergreen forest
(d) tropical rain forest
(a) savannah
51. What is PAR?
(a) Photoperiod Active Radiation
(b) Photosynthetically Active Radiation
(c) Photoperiod Active Resources
(d) Photosynthetically Active Resources.
(b) Photosynthetically Active Radiation
52. Tip of the ecological pyramid is occupied by?
(a) producers
(b) herbivores
(c) carnivores
(d) omnivores
(c) carnivores
53. In a food web, each successive trophic level has?
(a) increased total energy
(b) less total energy content
(c) more total energy content
(d) non-estimated energy content
(b) less total energy content
54. Who proposed the 10% law of energy flow in ecosystems?
(a) Lindeman
(b) Carl Mobius
(c) Tansley
(d) Darwin
(a) Lindeman
55. When the number of organisms at successive levels are plotted, they assume the shape of a pyramid. This is called the pyramid of?
(a) energy
(b) number
(c) biomass
(d) both (a) and (c)
(b) number
56. Why do Tropical deciduous forest trees shed their leaves?
(a) protect themselves from heat.
(b) save energy.
(c) enhance the rate of respiration.
(d) prevent loss of water.
(d) prevent loss of water.
57. What is a succession in saline soil?
(a) Mesosere
(b) Lethasere
(c) Psammosere
(d) Halosere
(d) Halosere
58. What is the name of the species that invade a bare area?
(a) keystone species
(b) extinct species
(c) pioneer species
(d) rare species
(c) pioneer species
59. Which one of the following is a major constituent of biological membranes, nucleic acids and cellular energy transfer systems?
(a) Phosphorus
(b) Carbon
(c) Oxygen
(d) Nitrogen
(a) Phosphorus
60. Which one of the following is considered as the pioneer community in xerarch?
(a) Annual herb
(b) Perennial herb
(c) Scrub stage
(d) Lichen
(d) Lichen
61. What are the early settlers on a barren area (rock)?
(a) Ferns
(b) Mosses
(c) Lichens
(d) Diatoms
(c) Lichens
62. Which community starts succession in a habitat?
(a) Pioneer community
(b) Seral community
(c) Biotic community
(d) Ecosphere
(a) Pioneer community
63. Last stabilised community in a plant succession is known as?
(a) Seral community
(b) Pioneer community
(c) Ecosere
(d) Climax community
(d) Climax community
64. Intermediate communities between pioneer and climax communities are called?
(a) Seral community
(b) Biotic community
(c) Temporary community
(d) Ecosphere
(a) Seral community
65. Trophic level in a food chain which cycles the various materials between environment and living organisms is constituted by?
(a) producers
(b) consumers
(c) decomposers
(d) All of these
(c) decomposers
66. What is ecological succession on sand?
(a) Psammosere
(b) Xerosere
(c) Halosere
(d) Hydrosere
(a) Psammosere
67. In ecological succession from pioneer to climax community, the biomass shall?
(a) decrease
(b) increase and then decrease
(c) no relation
(d) increase continuously
(d) increase continuously
68. Find out the correct order of succession levels in Xerarch
(a) Lichen moss stage, Annual herb stage, Perennial herb stage, Scrub stage, Forest
(b) Annual herb stage, Perennial herb stage, Lichen moss stage, Scrub stage, Forest
(c) Perennial herb stage, Annual herb stage, Perennial Scrub stage, Lichen moss stage, Forest
(d) Scrub stage, Forest, Annual herb stage, Lichen moss stage, Scrub stage, Forest
(a) Lichen moss stage, Annual herb stage, Perennial herb stage, Scrub stage, Forest
69. Phosphorus usually becomes a limiting factor at certain times of the year in which ecosystem?
(a) Aquatic ecosystem
(b) Grassland ecosystem
(c) Forest ecosystem
(d) All of the above
(a) Aquatic ecosystem
70. Which of the following in an ecosystem exhibits one-way flow rather than cyclic flow?
(a) Potassium
(b) Carbon
(c) Free energy
(d) Nitrogen
(c) Free energy
71. Which ecosystem does not show variations dependent upon geographic location and rainfall?
(a) Marine ecosystem
(b) Freshwater ecosystem
(c) Desert ecosystem
(d) Tropical ecosystem
(a) Marine ecosystem
72. Which of the following statements is not a major concern about our altering of the carbon cycle?
(a) The Greenland and Antarctic ice caps are expected to melt if global warming continues.
(b) High-sulphur fuels are used by power plants because they are less expensive than low-sulphur fuels.
(c) The increase in atmospheric CO2 exceeds the ability of the oceans to absorb the increase.
(d) CO2 is a gas that traps infrared radiation.
(b) High-sulphur fuels are used by power plants because they are less expensive than low-sulphur fuels.
73. Which of the following is expected to have the highest value (gm/m2/yr) in a grassland ecosystem?
(a) Secondary Production
(b) Tertiary Production
(c) Gross Production (GP)
(d) Net Production (NP)
(c) Gross Production (GP)
74. Approximately 70% of the world’s fresh water is contained in?
(a) polar ice
(b) glaciers and mountains
(c) Antarctica
(d) Greenland
(a) polar ice
75. The construction of ecological pyramids does not involve the use of?
(a) Number of individuals
(b) Rate of energy flow
(c) Fresh weight
(d) Dry weight
(c) Fresh weight
76. A lake near a village suffered heavy mortality of fishes within a few days. Consider the following reasons for this
1. Lots of urea and phosphate fertilizer were used in the crops in the vicinity
2. The area was sprayed with DDT by an aircraft
3. The lake water turned green and stinky
4. Phytoplankton populations in the lake declined initially thereby greatly reducing photosynthesis.
What were the two main causes of fish mortality in the lake?
(a) 2 and 3
(b) 3 and 4
(c) 1 and 3
(d) 1 and 2
(c) 1 and 3
77. About 70% of total global carbon is found in?
(a) grasslands
(b) agroecosystems
(c) oceans
(d) forests
(c) oceans
78. Consider the following statements concerning food chains
1. Removal of 80% tigers from an area resulted in greatly increased growth of vegetation
2. Removal of most of the carnivores resulted in an increased population of deers
3. The length of food chains is generally limited to 3-4 trophic levels due to energy loss
4. The length of food chains may vary from 2 to 8 trophic levels
Which of the following statements are correct?
(a) 2 and 3
(b) 3 and 4
(c) 1 and 4
(d) 1 and 2
(a) 2 and 3
79. Which one of the following types of organisms occupy more
than one trophic level in a pond ecosystem?
(a) Fish
(b) Zooplankton
(c) Frog
(d) Phytoplankton
(a) Fish
80. Study the four statements (a–d) given below and select the two correct ones out of them:
1. A lion eating a deer and a sparrow feeding on grain are ecologically similar in being consumers
2. Predator starfish Pisaster helps in maintaining species diversity of some invertebrates
3. Predators ultimately lead to the extinction of prey species
4. Production of chemicals such as nicotine, strychnine by the plants are metabolic disorders
The two correct statements are:
(a) 2 and 3
(b) 3 and 4
(c) 1 and 4
(d) 1 and 2
(d) 1 and 2
81. What do you call the biomass that herbivores and decomposers can consume?
(a) net primary productivity
(b) secondary productivity
(c) standing crop
(d) gross primary productivity
(a) net primary productivity
82. Which of the following statements regarding a pyramid of energy is incorrect, while the other three are correct?
(a) Its base is broad
(b) It shows the energy content of different trophic level organisms
(c) It is inverted in shape
(d) It is upright in shape
(c) It is inverted in shape
83. What do both hydrarch and xerarch successions lead to?
(a) medium water conditions
(b) xeric conditions
(c) highly dry conditions
(d) excessive wet conditions
(a) medium water conditions
84. The rate of formation of new organic matter by a rabbit in grassland is called?
(a) net productivity
(b) secondary productivity
(c) net primary productivity
(d) gross primary productivity
(b) secondary productivity
85. Which of the following is not an ecosystem function?
(a) Energy flow
(b) Decomposition
(c) Productivity
(d) Stratification
(d) Stratification
86. What is the natural reservoir of phosphorus?
(a) Animal bones
(b) Rock
(c) Fossils
(d) Seawater
(b) Rock
87. Pneumatophores are characteristic of plants that grow in?
(a) saline soils
(b) sandy soils
(c) marshy places and salt lakes
(d) dryland regions
(c) marshy places and salt lakes
88. What is the producer in the chain when a man eats fish that feed on zooplankton that has eaten small plants?
(a) Zooplankton
(b) Small plants
(c) Fish
(d) Man
(b) Small plants
89. Food chains differ from food webs as
1. food chains are a single sequence of who eats whom in a community.
2. food chains better represent the entire community.
3. food webs represent the complex interaction among food chains.
4. food chain is the flow of energy in a population.
(a) 1 and 3
(b) 1 and 4
(c) 1, 2 and 3
(d) 1, 2, 3 and 4
(a) 1 and 3
90. Which of the following include (s) ecosystem services?
1. Purification of air and water by forests
2. Forests mitigate droughts and flood
3. Forests act as a storehouse of carbon
4. Forests influence the hydrological cycle
(a) 1 and 3
(b) 1 and 4
(c) 1, 2 and 3
(d) All of these
(d) All of these
91. Mineralisation by microorganisms aids in the release of?
(a) inorganic nutrients from the humus
(b) both organic and inorganic nutrients from detritus
(c) organic nutrients from the humus
(d) inorganic nutrients from detritus and formation of humus.
(a) inorganic nutrients from the humus
92. In which ecosystem can an inverted pyramid of biomass be found?
(a) Forest
(b) Marine
(c) Grassland
(d) Tundra
(b) Marine
93. Which of the following is not a producer?
(a) Spirogyra
(b) Agaricus
(c) Volvox
(d) Nostoc
(b) Agaricus
94. Which of the following ecosystems is most productive in terms of net primary production?
(a) Deserts
(b) Tropical rain forests
(c) Oceans
(d) Estuaries
(b) Tropical rain forests
95. Pyramid of numbers is?
(a) Always upright
(b) Always inverted
(c) Either upright or inverted
(d) Neither upright nor inverted
(c) Either upright or inverted
96. Approximately how much of the solar energy falls on the leaves of a plant are converted to chemical energy by photosynthesis?
(a) Less than 1%
(b) 2 – 10%
(c) 30%
(d) 50%
(b) 2 – 10%
97. In which of the following would decomposition occur most quickly?
(a) Tropical rain forest
(b) the Antarctic
(c) Dry arid region
(d) Alpine region
(a) Tropical rain forest
98. How much of the net primary productivity of a terrestrial ecosystem is eaten and digested by herbivores?
(a) 1%
(b) 10%
(c) 40%
(d) 90%
(b) 10%
99. What are the changes that occur in communities as a result of ecological succession?
(a) orderly and sequential
(b) random
(c) very quick
(d) not influenced by the physical environment
(a) orderly and sequential
100. The Climax community is in a state of?
(a) non-equilibrium
(b) equilibrium
(c) disorder
(d) constant change
(b) equilibrium
101. Among the following biogeochemical cycles which one does not have losses due to respiration?
(a) Phosphorus
(b) Nitrogen
(c) Sulphur
(d) All of the above
(d) All of the above
102. What is the sequence of primary succession in water?
(a) Phytoplankton, sedges, free-floating hydrophytes, rooted hydrophytes, grasses and trees.
(b) Phytoplankton, free-floating hydrophytes, rooted hydrophytes, sedges, grasses and trees.
(c) Free-floating hydrophytes, sedges, phytoplankton, rooted hydrophytes, grasses and trees.
(d) Phytoplankton, rooted submerged hydrophytes, floating hydrophytes, reed swamp, sedges, meadow and trees.
(d) Phytoplankton, rooted submerged hydrophytes, floating hydrophytes, reed swamp, sedges, meadow and trees.
103. The reservoir for the gaseous type of bio-geochemical cycle exists in the
(a) stratosphere
(b) atmosphere
(c) ionosphere
(d) lithosphere
(b) atmosphere
104. If the carbon atoms fixed by producers already have passed through three species, the trophic level of the last species would be
(a) scavenger
(b) tertiary producer
(c) tertiary consumer
(d) secondary consumer
(c) tertiary consumer
105. In an area where evaporation exceeds precipitation, and annual rainfall is below 100mm, which of the following type of ecosystem is expected?
(a) Grassland
(b) Shrubby forest
(c) Desert
(d) Mangrove
(c) Desert
106. At the edge of a lake or ocean, an area alternately exposed to air and immersed in water is called?
(a) pelagic zone
(b) benthic zone
(c) lentic zone
(d) littoral zone
(d) littoral zone
107. What does the edaphic factor refer to?
(a) water
(b) soil
(c) relative humidity
(d) altitude
(b) soil
108. Which of the following is an ecosystem service provided by a natural ecosystem?
(a) Cycling of nutrients
(b) Prevention of soil erosion
(c) Pollutant absorption and reduction of the threat of global warming
(d) All of the above
(d) All of the above
109. What is the natural reservoir of phosphorus?
(a) Animal bones
(b) Rock
(c) Fossils
(d) Seawater
(b) Rock
110. Which one of the following processes during decomposition is correctly described?
(a) Humification-Leads to the accumulation of dark coloured substance humus which undergoes microbial action at a fast rate
(b) Catabolism-Last step decomposition under fully anaerobic condition
(c) Leaching-Water soluble inorganic nutrients rise to the top layers of soil
(d) Fragmentation-Carried out by organisms such as earthworm
(d) Fragmentation-Carried out by organisms such as earthworm
111. Secondary productivity is the rate of formation of new organic matter by?
(a) Parasite
(b) Consumer
(c) Decomposer
(d) Producer
(b) Consumer
112. In the maize field ecosystem, which of the following is a primary consumer?
(a) Lion
(b) Grasshopper
(c) Wolf
(d) Phytoplankton
(b) Grasshopper
113. When a man eats fish that feeds on zooplankton which has eaten small plants, the producer in the chain is?
(a) Zooplankton
(b) Small plants
(c) Fish
(d) Man
(b) Small plants
114. The age pyramid with a broad base indicates?
(a) High percentage of young individuals
(b) High percentage of old individuals
(c) Low percentage of young individuals
(d) A stable population
(a) High percentage of young individuals
115. Vertical distribution of different species occupying different levels in a biotic community is known as?
(a) Stratification
(b) Zonation
(c) Pyramid
(d) Divergence
(a) Stratification
116. What is the mass of living material at a particular time at a trophic level?
(a) Standing state
(b) Net primary productivity
(c) Standing crop
(d) Gross primary productivity
(c) Standing crop
117. How is the rate of organic matter production during photosynthesis defined in an ecosystem?
(a) Gross primary productivity
(b) Secondary productivity
(c) Net productivity
(d) Net primary productivity
(a) Gross primary productivity
118. Secondary Succession takes place on/in?
(a) Degraded forest
(b) Newly created pond
(c) Newly cooled lava
(d) Bare rock
(a) Degraded forest
119. During ecological succession?
(a) the establishment of a new biotic community is very fast in its primary phase.
(b) the numbers and types of animals remain constant.
(c) the changes lead to a community that is in near equilibrium with the environment and is called a pioneer community.
(d) the gradual and predictable change in species composition occurs in a given area.
(d) the gradual and predictable change in species composition occurs in a given area.
120. The increase in a toxicant’s concentration at successive trophic levels is called?
(a) Biodeterioration
(b) Biotransformation
(c) Biogeochemical
(d) Biomagnification
(d) Biomagnification
121. During biological nitrogen fixation, inactivation of nitrogenase by oxygen, poisoning is prevented by?
(a) Xanthophyll
(b) Carotene
(c) Cytochrome
(d) Leghemoglobin
(d) Leghemoglobin
122. An association of individuals from different species living in the same habitat and having functional interactions is called?
(a) Biotic community
(b) Ecosystem
(c) Population
(d) Ecological niche
(a) Biotic community
123. Most animals living in deep oceanic waters are?
(a) secondary consumers
(b) tertiary consumers
(c) detritivores
(d) primary consumers
(c) detritivores
124. What is a characteristic feature of the cropland ecosystem?
(a) Absence of soil organisms
(b) Least genetic diversity
(c) Absence of weeds
(d) Ecological succession
(b) Least genetic diversity
125. Which of the following organisms would appear as the pioneer organisms on bare rocks?
(a) Lichens
(b) Liverworts
(c) Mosses
(d) Green algae
(a) Lichens
126. Who coined the term ecosystem?
(a) E.P. Odum
(b) A.G. Tansley
(c) E.Haeckel
(d) E. Warming
(b) A.G. Tansley
127. What ecosystem has the highest biomass?
(a) Grassland ecosystem
(b) Pond ecosystem
(c) Lake ecosystem
(d) Forest ecosystem
(d) Forest ecosystem
Goodluck Medicoholics! Until next time.