Q1. Which of the following statements about 'Energy Flow' are true? (i) Sun is the only source of energy for all ecosystems except deep sea hydro-thermal. (ii) Flow of energy is unidirectional. (iii) Only 10 per cent of energy is transferred to each trophic level.
Correct Answer: (a)
Comprehensive summary of energy flow facts from pages 5-7.
Q2. Select correct statements for 'GFC': (i) It is the major conduit for energy flow in aquatic systems. (ii) It begins with producers. (iii) It ends with top carnivores.
Correct Answer: (a)
GFC details from page 5/6.
Q3. Assertion: Energy flow in an ecosystem is unidirectional.
Reason: Energy is transferred from the sun to producers and then to consumers.
Correct Answer: (a)
Page 5: You find unidirectional flow of energy from the sun to producers and then to consumers.
Q4. The process of humification leads to the accumulation of a ______ substance.
Correct Answer: (c)
Page 4: Humification leads to accumulation of a dark coloured amorphous substance called humus.
Q5. Match the ecosystems in Column-I with their types in Column-II:
Column-I
Column-II
A. Forest
(I) Aquatic
B. River
(II) Terrestrial
C. Aquarium
(III) Man-made
D. Crop field
(IV) Man-made
Correct Answer: (a)
Classification from page 1.
Q6. Regarding 'Primary Productivity', which are true? (i) It is expressed in terms of energy as kcal m^-2 yr^-1. (ii) It depends on photosynthetic capacity of plants. (iii) Ocean productivity is higher than land productivity.
Correct Answer: (a)
Page 3: Land productivity is much higher (115 billion tons vs 55 in ocean).
Q7. Match the nutrient cycle types:
Column-I
Column-II
A. Gaseous
(I) Phosphorus
B. Sedimentary
(II) Carbon
Correct Answer: (a)
Types of cycles from page 10.
Q8. Assertion: Saprophytes are not given any place in ecological pyramids.
Reason: They play a vital role in the ecosystem as decomposers.
Correct Answer: (a)
Page 10: This is a listed limitation of pyramids, despite their importance.
Q9. Assertion: Humus serves as a reservoir of nutrients.
Reason: It is colloidal in nature.
Correct Answer: (a)
Page 4: Being colloidal in nature it serves as a reservoir of nutrients.
Q12. Assertion: Trophic level represents a functional level, not a species as such.
Reason: A given species may occupy more than one trophic level in the same ecosystem.
Correct Answer: (a)
Page 9: The functional role defines the level; one species can have multiple roles (e.g., sparrow).
Q13. What is the fate of energy trapped by a producer?
Correct Answer: (b)
Page 5: The energy trapped by the producer... is either passed on to a consumer or the organism dies.
Q14. The raw material for decomposition is called:
Correct Answer: (c)
Page 3: Dead plant remains... and dead remains of animals... constitute detritus, which is the raw material for decomposition.
Q15. Humus is highly resistant to ______ and undergoes decomposition slowly.
Correct Answer: (c)
Page 4: ...humus that is highly resistant to microbial action.
Q16. Assertion: Herbivores and plants are more adversely affected by competition than carnivores.
Reason: Competition is a potent force in organic evolution.
Correct Answer: (a)
Page 12: General observation in nature.
Q17. Who is the 'farmer’s friend' according to the text?
Correct Answer: (c)
Page 3: You may have heard of the earthworm being referred to as the farmer’s ‘friend’.
Q18. Plants capture only ______ per cent of the PAR.
Correct Answer: (c)
Page 5: Plants capture only 2-10 per cent of the PAR.
Q19. Which of the following are limitations of ecological pyramids? (i) It does not take into account the same species at two trophic levels. (ii) It assumes a simple food chain. (iii) Decomposers are not given a place.
Correct Answer: (a)
Standard limitations listed on page 10.
Q20. Match the growth models/curves:
Column-I
Column-II
A. J-shaped curve
(I) Logistic growth
B. Sigmoid curve
(II) Exponential growth
C. Carrying capacity
(III) Logistic growth limit
Correct Answer: (a)
Models from page 7/8.
Q21. Match the factors affecting decomposition rate:
Column-I
Column-II
A. Rich in Nitrogen
(I) Slower
B. Rich in Lignin
(II) Quicker
Correct Answer: (a)
Rate factors from page 4.
Q22. Match herbivore examples:
Environment
Example
A. Terrestrial
Insects
B. Aquatic
Molluscs
Correct Answer: (a)
Examples from page 5.
Q23. Assertion: The pyramid of energy is always upright.
Reason: When energy flows from one trophic level to the next, some energy is always lost as heat at each step.
Correct Answer: (a)
Page 9: Pyramid of energy is always upright... because when energy flows... some energy is always lost as heat.
Q24. Assertion: The pyramid of biomass in sea is generally inverted.
Reason: The biomass of phytoplankton far exceeds that of fishes.
Correct Answer: (a)
Page 9: The reason is false; the biomass of fishes far exceeds that of phytoplankton.
Q25. Which of the following is an example of a man-made ecosystem?
Correct Answer: (c)
Page 1: Crop fields and an aquarium may also be considered as man-made ecosystems.
Q26. Assertion: The earth's crust is the reservoir for the phosphorus cycle.
Reason: Phosphorus is a sedimentary type of nutrient cycle.
Correct Answer: (a)
Page 10: Sedimentary cycles have their reservoir in the crust.
Q27. Assertion: Primary productivity varies in different types of ecosystems.
Reason: It depends on environmental factors, availability of nutrients and photosynthetic capacity of plants.
Correct Answer: (a)
Page 3: Factors listed in the reason determine the rate of production.
Q28. Which of the following is a limitation of ecological pyramids?
Correct Answer: (b)
Page 10: ...it does not take into account the same species belonging to two or more trophic levels.
Q29. Assertion: Humification and mineralisation occur during decomposition in the soil.
Reason: Humus is further degraded by some microbes to release inorganic nutrients.
Correct Answer: (a)
Page 4: Mineralisation is the release of inorganic nutrients from the degradation of humus.
Q30. Match the pyramid levels:
A. Base
Producers
B. Apex
Top consumers
Correct Answer: (a)
Pyramid structure from page 8.
Q31. Match the organism with its role in the food chain:
A. Cow
Primary consumer
B. Wolf
Secondary consumer
C. Man
Top consumer (Quaternary)
Correct Answer: (a)
Roles from Figure 12.2 on page 6.
Q32. Match nutrient cycles and reservoirs:
A. Carbon cycle
Atmosphere/Hydrosphere
B. Phosphorus cycle
Earth's Crust
Correct Answer: (a)
Reservoirs from page 10/Summary.
Q33. Zooplankton and grasshoppers occupy which trophic level?
Correct Answer: (b)
Page 6: ...herbivores (primary consumer) to the second (trophic level). Examples: Zooplankton, grasshopper.
Q34. Vertical distribution of different species occupying different levels in a community is called:
Correct Answer: (b)
Page 2: Vertical distribution of different species occupying different levels is called stratification.
Q35. In a forest ecosystem, which of the following occupy the bottom layers?
Correct Answer: (c)
Page 2: ...herbs and grasses occupy the bottom layers.
Q36. Match the man-made vs natural ecosystems:
A. Desert
Natural
B. Crop field
Man-made
Correct Answer: (a)
Classification from page 1.
Q37. Of the incident solar radiation, less than ______ per cent of it is photosynthetically active radiation (PAR).
Correct Answer: (c)
Page 5: Of the incident solar radiation less than 50 per cent of it is photosynthetically active radiation (PAR).
Q38. Assertion: Decomposers are also called saprotrophs.
Reason: They break down dead and waste materials into simple, inorganic materials.
Correct Answer: (a)
Page 6: Sapro means to decompose; their function defines their name.
Q39. The reservoir for the gaseous type of nutrient cycle (carbon) is the:
Correct Answer: (b)
Page 10: Atmosphere or hydrosphere is the reservoir for the gaseous type of cycle (carbon).
Q40. The number of trophic levels in a grazing food chain is restricted by the:
Correct Answer: (b)
Page 7: ...the transfer of energy follows 10 per cent law – only 10 per cent of the energy is transferred to each trophic level.
Q41. The source of energy for the deep sea hydro-thermal ecosystem is:
Correct Answer: (b)
Page 5: Except for the deep sea hydro-thermal ecosystem, sun is the only source of energy...
Q42. Assertion: Low temperature and anaerobiosis inhibit decomposition.
Reason: This results in the build-up of organic materials.
Correct Answer: (a)
Page 4: Lack of oxygen and low temperature stop microbes, leading to material accumulation.
Q43. The reservoir for the sedimentary type of nutrient cycle (phosphorus) is:
Correct Answer: (b)
Page 10: ...Earth’s crust is the reservoir for sedimentary type (phosphorus).
Q44. Which of the following describes the trophic level of a wolf?
Q45. Identify correct features of 'Standing Crop': (i) It is measured as biomass or number per unit area. (ii) It represents the mass of living material at a particular time. (iii) It is measured in terms of dry weight for accuracy.
Q46. Regarding 'Nutrient Cycling', which are correct? (i) Nutrients are never lost but repeatedly used. (ii) Gaseous cycle reservoir is the atmosphere. (iii) Sedimentary cycle reservoir is the Earth's crust.
Correct Answer: (a)
Facts from page 10 and Summary.
Q47. The pyramid of number in an ecosystem based on 6 million plants supports only ______ top-carnivores.
Correct Answer: (a)
Page 8/Figure 12.4(a): Only three top-carnivores are supported in an ecosystem based on production of nearly 6 millions plants.
Q48. Which of the following statements about 'Decomposition' are correct? (i) It is largely an oxygen-requiring process. (ii) Humus is highly resistant to microbial action. (iii) Low temperature and anaerobiosis favor decomposition.
Correct Answer: (a)
Page 4: Low temperature and anaerobiosis inhibit decomposition.
Q49. Assertion: All organisms are dependent for their food on producers.
Reason: Producers fix Sun's radiant energy to make food.
Correct Answer: (a)
Page 5: Dependence stems from the unique ability of producers to trap solar energy.
Q50. Match the units for biomass:
A. Fresh weight
Variable
B. Dry weight
More accurate
Correct Answer: (a)
Accuracy mentioned on page 7.
Q51. An ecosystem can be visualised as a ______ unit of nature.
Correct Answer: (b)
Page 1: An ecosystem can be visualised as a functional unit of nature.
Q52. What is the relationship between GPP, NPP, and Respiration (R)?
Correct Answer: (c)
Page 3: Gross primary productivity minus respiration losses (R), is the net primary productivity (NPP). GPP – R = NPP.
Q53. Which of the following is correct for 'DFC'? (i) It begins with dead organic matter. (ii) In terrestrial ecosystems, it carries more energy than GFC. (iii) It is made up of decomposers like fungi and bacteria.
Correct Answer: (a)
DFC details from page 6.
Q54. The primary consumers in a terrestrial ecosystem are typically:
Correct Answer: (b)
Page 5: Some common herbivores are insects, birds and mammals in terrestrial ecosystem.
Q55. Assertion: Standing crop is measured as the mass of living organisms.
Reason: Measurement of biomass in terms of dry weight is more accurate.
Correct Answer: (a)
Both are true statements from page 7, but accuracy of weight doesn't explain the definition of standing crop.
Q56. The process by which water-soluble inorganic nutrients go down into the soil horizon and get precipitated as unavailable salts is:
Correct Answer: (b)
Page 3: By the process of leaching, water-soluble inorganic nutrients go down into the soil horizon...
Q57. The mass of living material at a particular time in a trophic level is called:
Correct Answer: (b)
Page 7: Each trophic level has a certain mass of living material at a particular time called as the standing crop.
Q58. The rate of formation of new organic matter by consumers is called:
Correct Answer: (c)
Page 3: Secondary productivity is defined as the rate of formation of new organic matter by consumers.
Q59. Assertion: High temperature and moisture favor decomposition.
Reason: These conditions inhibit the activities of soil microbes.
Correct Answer: (a)
Page 4: These conditions regulate/favour activities, they do not inhibit them.
Q60. Identify correct facts for 'Ramdeo Misra': (i) Revived ecology in India. (ii) Obtained PhD in UK under Prof. W. H. Pearsall. (iii) Formulated first postgraduate course in ecology in India.
Correct Answer: (a)
Biography from page 2.
Q61. Match the following regarding pond components:
Column-I
Column-II
A. Solar input
(I) Producer
B. Phytoplankton
(II) Consumer
C. Zooplankton
(III) Abiotic/Regulator
D. Fungi
(IV) Decomposer
Correct Answer: (a)
Pond ecosystem description on page 2.
Q62. Primary producers convert what percentage of sunlight available to them into NPP?
Correct Answer: (d)
Page 9/Figure 12.4(d): Observe that primary producers convert only 1% of the energy in the sunlight available to them into NPP.
Q63. A sparrow is a primary consumer when it eats:
Correct Answer: (c)
Page 9: ...a sparrow is a primary consumer when it eats seeds, fruits, peas...
Q64. Match the organisms with their trophic levels:
Column-I
Column-II
A. Phytoplankton
(I) Fourth Trophic level
B. Grasshopper
(II) Third Trophic level
C. Fishes
(III) Second Trophic level
D. Lion
(IV) First Trophic level
Correct Answer: (a)
Trophic levels as per Figure 12.2 on page 6.
Q65. Which of the following is true for 'PAR'? (i) It is less than 50% of incident radiation. (ii) Only 2-10% of it is used by plants. (iii) It sustains the entire living world.
Correct Answer: (a)
Energy flow intro on page 5.
Q66. Which of the following is true for 'Humus'? (i) It is dark coloured amorphous substance. (ii) It is a reservoir of nutrients. (iii) It is crystalline in nature.
Correct Answer: (a)
Page 4: Humus is amorphous, not crystalline.
Q67. Despite occupying 70% of the surface, the productivity of the oceans is only:
Correct Answer: (b)
Page 3: ...the productivity of the oceans are only 55 billion tons.
Q68. Identify the correct statements regarding 'Productivity': (i) GPP is the rate of production of organic matter during photosynthesis. (ii) NPP is GPP minus respiration losses. (iii) NPP is the available biomass for consumers.
Correct Answer: (a)
All these points are standard definitions from page 3.
Q69. Match abiotic vs biotic in a pond:
A. Water/Soil
Abiotic
B. Algae/Fungi
Biotic
Correct Answer: (a)
Pond components from page 2.
Q70. Correct statements for 'Parasitism' include: (i) Many parasites are host-specific. (ii) Brood parasitism is seen in birds. (iii) Endoparasites live inside the host body.
Correct Answer: (a)
Parasitism details from page 13.
Q71. Match the productivity terms:
Column-I
Column-II
A. NPP
(I) Rate of production of organic matter during photosynthesis
B. GPP
(II) Available biomass for heterotrophs
C. Secondary productivity
(III) Rate of formation of new organic matter by consumers
Correct Answer: (a)
Productivity definitions from page 3.
Q72. Which ecological pyramid can NEVER be inverted?
Correct Answer: (c)
Page 9: Pyramid of energy is always upright, can never be inverted.
Q73. Assertion: A pond is a self-sustainable unit.
Reason: It performs all the functions of an ecosystem like productivity and decomposition.
Correct Answer: (a)
Page 2: The functional integrity of its processes makes it self-sustainable.
Q74. Which of the following is correct regarding 'Competition'? (i) Unrelated species can compete for the same resource. (ii) Resources need not be limiting for competition to occur. (iii) Abingdon tortoise was eliminated by goats.
Correct Answer: (a)
Competition nuances from page 11/12.
Q75. Which statements describe the 'Pond Ecosystem' correctly? (i) Abiotic components include water and rich soil deposit. (ii) Decomposers include fungi, bacteria, and flagellates. (iii) Autotrophic components include zooplankton.
Correct Answer: (a)
Page 2: Zooplankton are consumers, not autotrophs.
Q76. What is the unit of measurement for productivity?
Correct Answer: (c)
Page 3: It is expressed in terms of gm–2 yr –1 or (kcal m–2 ) yr –1.
Q77. The annual net primary productivity of the whole biosphere is approximately:
Correct Answer: (c)
Page 3: The annual net primary productivity of the whole biosphere is approximately 170 billion tons.
Q78. Match the steps of decomposition with descriptions:
Column-I
Column-II
A. Fragmentation
(I) Release of inorganic nutrients
B. Leaching
(II) Breakdown into smaller particles
C. Catabolism
(III) Nutrients moving into soil profile
D. Mineralisation
(IV) Enzymatic degradation to simple inorganic substances
Correct Answer: (a)
Definitions from page 3/4.
Q79. Assertion: Net primary productivity (NPP) is less than Gross primary productivity (GPP).
Reason: A considerable amount of GPP is utilised by plants in respiration.
Correct Answer: (a)
Page 3: GPP – R = NPP. Respiration loss (R) makes NPP lower than GPP.
Q80. In the DFC, energy comes from:
Correct Answer: (b)
Page 6: The detritus food chain (DFC) begins with dead organic matter.
Q81. The pyramid of biomass in the sea is generally:
Correct Answer: (b)
Page 9: The pyramid of biomass in sea is generally inverted because the biomass of fishes far exceeds that of phytoplankton.
Q82. Identify true statements for 'Interspecific Interactions': (i) Beneficial is '+'. (ii) Detrimental is '-'. (iii) Neutral is '0'.
Correct Answer: (a)
Standard symbols from page 9.
Q83. Bacterial and fungal enzymes degrade detritus into simpler inorganic substances. This process is:
Correct Answer: (c)
Page 3: Bacterial and fungal enzymes degrade detritus into simpler inorganic substances. This process is called as catabolism.
Q84. Producers belong to which trophic level?
Correct Answer: (a)
Page 6: Producers belong to the first trophic level.
Q85. In an aquatic ecosystem, the major conduit for energy flow is the:
Correct Answer: (b)
Page 6: In an aquatic ecosystem, GFC is the major conduit for energy flow.
Q86. Regarding 'Ecological Pyramids', which are correct? (i) Pyramid of energy is always upright. (ii) Pyramid of biomass in sea is generally inverted. (iii) Pyramid of number in grassland is inverted.
Correct Answer: (a)
Page 8: Pyramid of number in grassland is upright; 6 million plants support 3 top carnivores.
Q87. Decomposition rate is slower if the detritus is rich in:
Correct Answer: (c)
Page 4: ...decomposition rate is slower if detritus is rich in lignin and chitin.
Q88. Match the consumer categories:
Column-I
Column-II
A. Primary Consumer
(I) Carnivores feeding on herbivores
B. Secondary Consumer
(II) Herbivores
C. Tertiary Consumer
(III) Top carnivores
Correct Answer: (a)
Consumer levels from page 5/6.
Q89. Which of the following is correct? (i) Interaction of biotic and abiotic result in stratification. (ii) Decomposition is an oxygen-requiring process. (iii) Energy flow is unidirectional.
Correct Answer: (a)
Core concepts found in the summary and main text.
Q90. Match structural vs functional features:
Column-I
Column-II
A. Species composition
(I) Functional aspect
B. Nutrient cycling
(II) Structural aspect
Correct Answer: (a)
Anatomy of ecosystem from page 2/Summary.
Q91. Match the product of decomposition:
A. Humification
Humus
B. Mineralisation
Inorganic nutrients
Correct Answer: (a)
Processes from page 4.
Q92. Decomposers are also known as:
Correct Answer: (c)
Page 6: Decomposers... are also known as saprotrophs.
Q93. Assertion: In a terrestrial ecosystem, a larger fraction of energy flows through DFC than GFC.
Reason: Detritus food chain begins with dead organic matter.
Correct Answer: (a)
Both are true facts from page 6, but the definition of DFC isn't the explanation for why more energy flows through it in land systems.
Q94. Assertion: Detritivores break down detritus into smaller particles.
Reason: This process is called catabolism.
Correct Answer: (a)
Page 3: Breaking into smaller particles is fragmentation, not catabolism.
Q95. The amount of biomass or organic matter produced per unit area over a time period by plants during photosynthesis is called:
Correct Answer: (b)
Page 2/3: Primary production is defined as the amount of biomass or organic matter produced per unit area over a time period by plants.
Q96. Which of the following are 'Ecosystem Services'? (i) Purification of air and water by forests. (ii) Nutrient cycling. (iii) Carbon fixation.
Correct Answer: (a)
Summary page 10 mentions these as products of ecosystem processes.
Q97. Match the food chains:
Column-I
Column-II
A. GFC
(I) Begins with dead organic matter
B. DFC
(II) Begins with producers
Correct Answer: (a)
Chain definitions from page 5/6.
Q98. Assertion: The 10 per cent law restricts the number of trophic levels.
Reason: Only 10 per cent of energy is transferred to each higher trophic level.
Correct Answer: (a)
Page 7: Energy scarcity at higher levels limits the number of possible levels.
Q99. Which of the following is NOT one of the four basic components of an ecosystem?
Correct Answer: (b)
Page 2: The components... are seen to function as a unit when you consider... (i) Productivity (ii) Decomposition (iii) Energy flow (iv) Nutrient cycling.
Q100. Identify the correct statements for 'Resource Partitioning': (i) It promotes co-existence rather than exclusion. (ii) Five species of warblers showed behavioral differences to avoid competition. (iii) It was studied by MacArthur.
Correct Answer: (a)
Page 12: Detailed findings by MacArthur on warblers.
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