18 Chapter

Ecosystem

MULTIPLE CHOICE QUESTIONS

Topic Ecosystem: Structure and Topic Productivity

1 Function 2

1. The autotrophic components include 7. Net primary productivity (NPP) equals to

(a) Phytoplankton (b) Some algae (a) NPP = R – GPP (b) GPP – R = NPP
(c) Marginal plants (d) All of these (c) NPP = GPP + R (d) GPP = R – NPP
2. The decomposers is/are the 8. The rate of formation of new organic matter by
(a) Fungi (b) Bacteria consumers is called as
(c) Flagellates (d) All of these (a) primary productivity
(b) Gross primary productivity
3. The consumers is/are
(c) Secondary productivity
(a) Zooplankton (b) Phytoplanktons
(d) Respiratory loss
(c) Marginal plants (d) All of these
4. Vertical distribution of different species occupying 9. Primary productivity depends on
different levels is called as (a) Variety of environmental factors
(a) Standing crop (b) Standing state (b) Availability of nutrients
(c) Stratification (d) Decomposition (c) Photosynthetic capacity of plant
(d) All of these
5. Identification and enumeration of plant and animal
species of an ecosystem gives its 10. The annual net primary productivity of the whole
(a) Productivity biosphere is approximately
(b) Species composition (a) 190 million tons (b) 170 million tons
(c) Physical structure (c) 170 billion tons (d) None of these
(d) Vertical distribution
11. What is the basic requirement for any ecosystem
6. Which one of the following is odd one out from to function and sustain.
others (a) Primary production
(a) Decomposition (b) Decomposers
(b) Energy flow (c) Constant input of solar energy
(c) Nutrient cycling (d) Nutrient cycling
(d) None
12. ________ is defined as the amount of biomass
or organic matter produced per unit area over a
time period by plants during photosynthesis
(a) Gross primary productivity
214 Botany
(b) Primary production (a) Earthworm
(c) Secondary production (b) Detritivores
(d) None of these (c) Phytoplanktons
(d) Both A & B are correct
13. Primary production is expressed as-
(a) K Clam2 (b) K Clam/m2 21. Bacteria and fungal enzymes degrade detritus
(c) g/m2 (d) both (a) & (c) into simpler inorganic substances. This process
is called as
14. ______ of an ecosystem is the rate of production
(a) Leaching (b) Fragmentation
of organic matter during photosynthesis
(c) Catabolism (d) Humification
(a) Net primary productivity
(b) Secondary production 22. Humification leads to accumulation of a dark
(c) Gross primary productivity coloured amorphous substance called _______
(d) None of these (a) Pectin (b) Humus
(c) Lignin (d) None of these
Topic Decomposition
3 23. Decomposition rate is slower if
(a) Detritus rich in lignin & chitin
15. Which one of the following is called as “farmer’s
friend”? (b) Rich in nitrogen & sugars
(a) Cow (b) Bacteria (c) Low in nitrogen & chitin
(c) Earthworm (d) Crops (d) Low in lignin

16. Who breaks down complex organic matter into 24. ________ favours decompositions
inorganic substances like CO2, water etc. (a) Warm & dry environment
(a) Crop roots (b) Decomposers (b) Warm & moist environment
(c) Grazing Cattle (d) None of these (c) cold & dry environment
(d) cold & moist environment
17. The process of breaks down complex organic
matter into inorganic substances is called as Topic Energy flow
(a) Fragmentation (b) Humification 4
(c) Decomposition (d) Leaching
18. Detritus is/are 25. PAR stands for
(a) Dead plant (b) Dead animals (a) Percent active radiation
(c) Fecal matter (d) All of these (b) Photosynthetically active radiation
(c) Power angel regulation
19. The correct way of decomposition (d) None of these
(a) Fragmentation → leaching → humification
→ catabolism → mineralization 26. Plant capture only ______ of the PAR and this
(b) Fragmentation → leaching → catabolism → amount of energy sustains the entire living world
humification → mineralization (a) 50 – 60 % (b) 40 – 80 %
(c) Fragmentation → catabolism → leaching → (c) 2 – 10 % (d) 20 – 40 %
mineralization → humification
27. The green plant in the ecosystem are called
(d) Fragmentation → mineralization →
(a) Primary consumer
catabolism → leaching → humification
(b) Producer
20. _________ break down detritus into smaller (c) Secondary consumer
particles (d) None of these
Ecosystem 215
28. Producers in an aquatic ecosystem (b) Producer → primary carnivore →herbivore
(a) Phytoplankton (b) Algae → secondary carnivore
(c) Zooplanktons (d) Both A & B (c) Primary carnivore → secondary carnivore
→ herbivore → Producer
29. Generally, primary consumers will be (d) None of these
(a) Carnivores (b) Producers
(c) Herbivores (d) All of these Topic Ecological Pyramids
30. In ecosystem, GFC stands for 5
(a) Generic flow control
(b) Global fund for children 37. Ecological pyramids are
(c) Grazing food chain (a) Pyramid of number
(d) None of these (b) Pyramid of energy
(c) Pyramid of biomass
31. Decomposers are also known as (d) All of these
(a) Autotrophs (b) Standing crops
(c) Saprotrophs (d) None of these 38. The pyramid of biomass in sea is
(a) Always upright
32. Based on the source of their nutrition or food,
(b) Generally inverted
organisms occupy a specific place in the food
(c) Both A & B
chain that is known as their
(d) None of these
(a) Food web (b) Trophic level
(c) Niche (d) Eco level 39. Pyramid of energy is
(a) Always inverted
33. Match the following
(b) Sometime upright
Column I Column II (c) Always upright
i Plants a Lion (d) Sometimes inverted
ii Carnivores b Phytoplanktons
40. Identify the pyramid
iii Herbivores c Wolf
iv Top Carnivores d Cow
(a) i-b, ii-c, iii-d, iv-a (b) i-c, ii-d, iii-b, iv-a
(c) i-b, ii-d, iii-a, iv-c (d) i-d, ii-b, iii-a, iv-c
34. Each tropical level has a certain mass of living
material at a particular time called as the (a) Pyramid of number
(a) Biomass (b) Standing crop (b) Pyramid of biomass
(c) Standing state (d) None of these
(c) Pyramid of energy
35. The standing crop is measured as the (d) None of these
(a) Mass of living organisms
41. Identify the pyramid
(b) Biomass
(c) The no. in a unit area
(d) All of these
36. Choose the correct sequence –
(a) Producer → herbivore → primary carnivore
→ secondary carnivore
216 Botany
(a) Pyramid of number (c) Natural biotic communities have been
(b) Pyramid of biomass destroyed
(c) Pyramid of energy (d) Both B & C
(d) None of these
48. Areas where secondary succession occurs
42. Identify the pyramid (a) Burned and cut forests areas
(b) Land that have been flooded
(c) Abandoned farm lands
(d) All are correct
49. Select the correct statement
(a) Pyramid of number (a) secondary succession is faster than primary
(b) Pyramid of biomass succession
(c) Pyramid of energy (b) primary succession is faster
(d) None of these (c) Both are a equal speed
(d) None of these
Topic Ecological succession
50. The individual transitional communities are
6 termed as
43. A community that is in near equilibrium with (a) Seral stages
the environment is called as (b) Pioneer
(a) Pioneer community (c) Seral communities
(b) Middle community (d) Both A & C are correct
(c) Climax community
(d) Sere Topic Succession of plants
7
44. The gradual and fairly predictable change in the
species composition of a given area is called 51. Which type of succession takes place in wet
(a) Hydrarch succession areas
(b) Ecological succession (a) Hydrarch succession
(c) Pioneer succession (b) Xerarch succession
(d) None of these (c) Mesarch succession
45. The entire sequence of communities that (d) None of these
successively change in a given area are called 52. Xerarch succession occurs in
(a) Ecosystem (b) Pioneer (a) Wet areas (b) Cold areas
(c) Sere (d) All of these (c) Dry areas (d) All of these
46. Areas where primary succession occurs 53. The species that invade a bare area called
(a) Bare rock (a) Sere (b) Pioneer species
(b) Newly cold lava (c) Climax species (d) None of these
(c) Newly created pond
(d) All of these 54. In hydrarch succession the successional series
progress from
47. Secondary succession begins in areas where (a) Mesic to hydric condition
(a) No living organism are there (b) Hydric to mesic condition
(b) Lost all the living organism (c) Hydric to xeric condition
Ecosystem 217
(d) Xeric to mesic condition (a) Scrub stage
(b) Tree
55. In xerarch succession, the succession series
(c) Zooplankton
progress from
(d) Submerged plant stage
(a) Xeric to hydric condition
(b) Xeric to mesic condition 60. During succession some species colonise an area
(c) Mesic to xeric condition and their population become more numerous
(d) None of these whereas population of other species
(a) Increases
56. Which one of the following occur as a pioneer
(b) Decline and even disappear
species on rocks
(c) Migrate
(a) Bryophytes
(d) None of these
(b) Phytoplankton
(c) Lichens 61. Why does secondary succession is faster?
(d) Blue algae (a) Because soil is already there
(b) They have special power
57. Choose the correct sequence of succession in
(c) Growth of plants is faster
water
(d) All of these
(a) Phytoplanktons → rooted-submerged plants
→ rooted floating angiosperms → free 62. The climax community remains _______ as long
floating plants → reed swamp → marsh- as the environment remains _______.
meadow → scrub → the trees → forest (a) Unstable, unchanged
(b) Phytoplanktons → free floating plants → (b) Stable, unchanged
rooted-submerged plants → rooted floating (c) Unstable, changed
angiosperms → reed swamp → scrub → (d) Stable, changed
marsh-meadow → the trees → forest
(c) Phytoplanktons → rooted-submerged 63. The word (term) use for medium water
plants → reed swamp → rooted floating conditions
angiosperms → free floating plants → (a) Xeric (b) Hydric
marsh-meadow → scrub → the trees → (c) Mesic (d) None of these
forest 64. Choose the correct sequence
(d) None of these i) lichens
58. Choose the correct statement- ii) Grasses
(a) All succession whether taking place in water iii) Bryophytes
or on land, proceeds to a different climax iv) Higher plants
community v) Forest
(b) All succession whether taking place in water (a) i → ii → iii → iv → v
or on land, proceeds to a similar climax (b) i → iii → ii → iv → v
community the mesic (c) i → iv → ii → iii → v
(c) All succession whether taking place in water (d) v → iv → i → ii → iii
or on land, proceeds to a similar climax 65. in hydrarch succession, after climax with time
community the xeric the water body is converted into
(d) All of these (a) River (b) Ocean
(c) Land (d) None of these
59. Which one of the following is not the part of
hydrarch succession
218 Botany
66. In hydrarch succession, the pioneer and climax (c) Temperature & pH
community are respectively (d) All of the above
(a) Forest, Phytoplanktons
(b) Phytoplanktons, Forest 74. Reason behind nutrients never lost from
(c) Mess, Trees ecosystem.
(d) Lichen, Trees (a) Because nutrients present in large amount
(b) Because they are recycled
Topic Nutrient Cycling (c) Because they have no use
8 (d) All of the above

67. The amount of nutrients such as carbon, nitrogen, Topic Ecosystem-Carbon Cycle
phosphorus, calcium etc present in the soil at 9
any given time is referred to as the
(a) Nutrients cycle (b) Standing crop 75. Percent of carbon constitutes in dry weight of
(c) Standing state (d) None of these organism
(a) 60% (b) 39%
68. Standing state varies in
(c) 49% (d) 71%
(a) Different kinds of ecosystem
(b) On a season basis 76. Which is the first & second most abundant
(c) Different kinds of nutrients constituent of an organism?
(d) Both A & B (a) Water, phosphorus
69. The movement of nutrients elements through (b) Water, carbon
the various components of an ecosystem can (c) Carbon, water
be called (d) Carbon, phosphorus
(a) Gaseous cycle
77. How much of total quantity of global carbon is
(b) Nutrient cycling
dissolved in the oceans?
(c) Sedimentary cycle
(d) All of these (a) 88% (b) 75%
(c) 81% (d) 71%
70. Another name of nutrient cycling is
(a) Gaseous cycle 78. Carbon cycling occurs through
(b) Biological cycle (a) Atmosphere
(c) Biogeochemical cycle (b) Living & dead organism
(d) Biophysical (c) Ocean
(d) All of the above
71. Reservoir for gaseous type of nutrient cycle
(a) Earth’s crust (b) Rock 79. How much at carbon in fixed annually in the
(c) The atmosphere (d) Water bodies biosphere through photosynthesis?
(a) 8 × 1012 kg (b) 4 × 1012 kg
72. Reservoir for sedimentary type of Nutrient cycle (c) 4 × 1013 kg (d) 4.9 × 10 kg
(a) Ocean (b) Earth’s crust
(c) Rock (d) Atmosphere 80. Additional sources for releasing CO2 in the
atmosphere is/are-
73. Environmental factor to regulate the rate of (a) Burning of wood (b) Forest fire
release of nutrients into the atmosphere. (c) Fossil fuel (d) All of the above
(a) Soil
(b) Moisture 81. Human activities have significantly increased the
rate of released of CO2 into the atmosphere by
Ecosystem 219
(a) Rapid deforestation (d) None at these
(b) Massive burning of fossil
88. In natural resevoirs, phosphorus present in the
(c) Both A and B
form of
(d) None of the above
(a) Phosphite (b) Pyrophosphate
Topic Ecosystem-Phosphorus Cycle (c) Phosphates (d) None of the above
89. Identify the blanks
10

82. Phosphorus is a major constituent of

(a) Biological membranes
(b) Nucleic acids
(c) Cellular energy transfer unit
(d) All of the above

83. Rock is the natural reservoir of

(a) Carbon
(b) Nitrogen
(c) Phosphorus A B C D
(d) None at these (a) Detritus Weather- Soil solution L i t t e r
84. Herbivores & other animals obtain Phosphorus ing fall
from (b) Litter fall Weather- Detritus Soil so-
(a) Rock (b) Plants ing lution
(c) Ocean (d) Lake (c) Weather- Litter fall Soil solution Detritus
ing
85. The waste products and the dead organism are
(d) Detritus Soil solu- Litter fall Weath-
decomposed by ________ releasing phosphorus.
tion ering
(a) Fungi
(b) Phosphate-solubilising bacteria 90. Which one of the following is not a Gaseous
(c) Phosphate-unsolubising bacteria nutrient cycle?
(d) None of the above (a) Oxygen cycle (b) Nitrogen cycle
86. Choose the correct statement. (c) Sulphur cycle (d) None of the above
(a) Atmospheric inputs of phosphorus through 91. Animals need large quantities of phosphorus to
rainfall are much smaller than carbon inputs. make
(b) Atmospheric inputs of phosphorus through (a) Shells (b) Teeth
rainfall are larger than carbon inputs. (c) Bones (d) All of the above
(c) Atmospheric inputs of phosphorus through
rainfall are equal to the carbon inputs. Topic Ecosystem Services
(d) None of the above 11
87. Choose the more correct statement.
92. ________ & his colleagues have very recently
(a) Gaseous exchange at phosphorus b/w
tried to put price tags on nature’s life-support
organism & environment are very high.
services.
(b) Gaseous exchange of phosphorus b/w
(a) Robert frost
organism & environment are low.
(b) Robert Constanza
(c) Gaseous exchange at phosphorus b/w
organism & environment are negligible.
220 Botany
(c) Robert hook 98. Choose the correct statement.
(d) Robert Clive (a) Value of Ecosystem services at biodiversity
is difficult to determine.
93. Researchers have put an average price tag of
(b) Value of Ecosystem services of biodiversity
________ a year on fundamental ecosystem
is very easy to determine.
services.
(c) No need to determine the value of Ecosystem
(a) US $ 33 billion (b) US $ 44 billion
services.
(c) US $ 44 trillion (d) US $ 33 trillion
(d) None of these
94. GNP stands for 99. The products of ecosystem processes are named
(a) Grand national product as
(b) Gross national product (a) Environmental services
(c) Gross national produce (b) Ecosystem goods
(d) None of these (c) Ecosystem services
95. Out of the total cost at various ecosystem (d) All of the above
services the soil formation accounts for about. 100. Healthy ecosystems are the base for a
(a) 40% (b) 60% (a) Wide range of economic
(c) 50% (d) 30% (b) Environmental
96. The cost of climate regulation & habitat for (c) Aesthetic goods & services
wildlife are (d) All of the above
(a) 8% each (b) 6% at overall 101. Examples of Ecosystem services
(c) 6% each (d) None at the above (a) Healthy forest ecosystem purify air & water
97. The value of the global GNP (b) Generate fertile soil
(a) US $ 28 trillion (b) US $ 18 Billion (c) Provide storage site for carbon
(c) US $ 33 trillion (d) US $ 18 trillion (d) All of the above
Ecosystem 221

ANSWER KEY
1. (d) 2. (d) 3. (a) 4. (c) 5. (b) 6. (d) 7. (b) 8. (c) 9. (d) 10. (c)
11. (c) 12. (b) 13. (d) 14. (c) 15. (c) 16. (b) 17. (c) 18. (d) 19. (b) 20. (d)
21. (c) 22. (b) 23. (a) 24. (b) 25. (b) 26. (c) 27. (b) 28. (d) 29. (c) 30. (c)
31. (c) 32. (c) 33. (a) 34. (b) 35. (d) 36. (a) 37. (d) 38. (b) 39. (c) 40. (b)
41. (c) 42. (a) 43. (c) 44. (b) 45. (c) 46. (d) 47. (d) 48. (d) 49. (a) 50. (d)
51. (a) 52. (c) 53. (b) 54. (b) 55. (b) 56. (a) 57. (a) 58. (b) 59. (c) 60. (b)
61. (a) 62. (b) 63. (b) 64. (b) 65. (c) 66. (b) 67. (c) 68. (d) 69. (d) 70. (c)
71. (c) 72. (b) 73. (d) 74. (b) 75. (c) 76. (b) 77. (d) 78. (d) 79. (c) 80. (d)
81. (c) 82. (d) 83. (c) 84. (b) 85. (b) 86. (a) 87. (c) 88. (c) 89. (d) 90. (c)
91. (d) 92. (b) 93. (d) 94. (b) 95. (c) 96. (c) 97. (d) 98. (a) 99. (c) 100. (d)
101. (d)