Ecology – Old Year Questions


1. ‘Ecology’ is the study of the relationship between–

(a) Organism and environment
(b) Man and forest
(c) Soil and water
(d) Husband and wife

[U.P.R.O./A.R.O. (Pre) 2014]


2. The term Ecosystem was proposed by –

(a) G. Tailor
(b) E. Hartigan
(c) D.R. Stoddart
(d) Tansley

[Uttarakhand P.C.S. (Pre) 2005]


3. Which of the following is not true about the ecosystem?

(a) It represents all living organisms and the physical environment in any given space-time unit.
(b) It is a functional unit.
(c) It has own productivity.
(d) It is a closed-system.

[U.P.P.C.S. (Mains) 2014]


4. Which four components constitute an ecosystem?

(a) Water, Carbon, Oxygen, Sulphur
(b) Soil, Temperature, Humidity, Rainfall
(c) Abiotic materials, Producers, Consumers, Decomposers
(d) Herbivores, Carnivores, Bacteria, Parasites

[Jharkhand P.C.S. (Mains) 2016]


5. Which one of the following is the best description of the term ‘ecosystem’?

(a) A community of organisms interacting with one another.
(b) That part of the Earth which is inhabited by living organisms.
(c) A community of organisms together with the environment in which they live
(d) Flora and fauna of a geographical area.

[I.A.S. (Pre) 2015]


6. Which of the following is an artificial ecosystem?

(a) Ponds
(b) Field
(c) Forest
(d) None of these

[Jharkhand P.C.S. (Pre) 2013]


7. Which of the following is an artificial ecosystem?

(a) Rice field
(b) Forest
(c) Grassland
(d) Lake

[U.P.P.C.S. (Pre) 2016]


8. The number of organisms that can be supported by the environment in a given area is known as:

(a) Population
(b) Carrying Capacity
(c) Pyramid of number or biomass
(d) None of the above

[Uttarakhand P.C.S. (Pre) 2012]


9. Which one of the following terms describes not only the physical space occupied by an organism but also its functional role in the community of organisms?

(a) Ecotone
(b) Ecological niche
(c) Habitat
(d) Home range

[I.A.S. (Pre) 2013]


10. The actual location or place where an organism lives is called:

(a) Habitat
(b) Ecosystem
(c) Niche
(d) Biome
(e) None of the above/More than one of the above

[U.P.P.C.S. (Pre) 2019]


11. Which one of the following ecosystems covers the largest area of the earth’s surface:

(a) Desert Ecosystem
(b) Grassland Ecosystem
(c) Mountain Ecosystem
(d) Marine Ecosystem

[U.P. Lower Sub. (Spl) (Pre) 2003]


12. Which one of the following is the largest ecosystem of the world?

(a) Ocean
(b) Grassland
(c) Forest
(d) Mountains

[U.P.P.C.S. (Pre) 2014]


13. Which of the following does not help to maintain ecological balance?

(a) Cutting forest
(b) Afforestation
(c) Rainwater Management
(d) Biosphere Reserves

[U.P.U.D.A./L.D.A. (Pre) 2013]


14. Which one of the following is one of the main causes of ecological imbalance in India?

(a) Deforestation
(b) Desertification
(c) Floods and Famines
(d) Rainfall variations

[R.A.S./R.T.S.(Pre) 2012]


15. Which of the following is an act that disturbs the ecological balance?

(a) Lumbering
(b) Social forestry
(c) Vanamahotsav
(d) Afforestation

[U.P.R.O./A.R.O. (Pre) 2014]


16. The highest trophic level in an ecosystem is obtained by:

(a) Herbivores
(b) Carnivores
(c) Omnivores
(d) Decomposers

[U.P.U.D.A./L.D.A. (Pre) 2002]


17. Which of the following is not a biotic component of an ecosystem?

(a) Air
(b) Plant
(c) Bacteria
(d) Animals

[R.A.S./R.T.S. (Pre) 2013]


18. The primary source of energy in Eco-body is –

(a) Energy emitted by fermentation
(b) Preserved vegetable sugar
(c) Solar energy
(d) None of the above.

[U.P.P.C.S. (Mains) 2015]


19. Driving force of an ecosystem is:

(a) Carbohydrate
(b) Biomass
(c) Carbon
(d) Solar energy

[U.P.R.O./A.R.O. (Re-Exam) (Pre) 2016]


20. Concerning the food chains in ecosystems, which of the following kinds of an organism is/are known as decomposer organisms/organisms?

1. Virus
2. Fungi

3. Bacteria

Select the correct answer using the code given below:

(a) Only 1
(b) 2 and 3
(c) 1 and 3
(d) All of these

[I.A.S. (Pre) 2013]


21. Which of the following are the primary consumers in an ecosystem? Select the correct answer from the codes given below:

1. Ants
2. Deer

3. Fox
4. Tiger

Code :

(a) 1 and 2
(b) 2 and 3
(c) 1, 2 and 3
(d) 2, 3 and 4

[U.P.P.C.S. (Mains) 2006]


22. In a food chain, man is:

(a) producer
(b) only primary consumer
(c) only secondary consumer
(d) primary as well as secondary consumer

[U.P.P.C.S. (Pre) 2016]


23. 10 Percent of law is related to:

(a) Transfer of energy as food from one trophic level to other
(b) Transfer of heat from one matter to another
(c) Transfer of birds from one zone to another
(d) Transfer of water from one zone to another
(e) None of these

[Chhattisgarh P.C.S. (Pre) 2016]


24. In the marine environment, the main primary producers are:

(a) Phytoplanktons
(b) Seaweeds
(c) Marine angiosperms
(d) Aquatic bryophytes

[U.P.P.C.S. (Mains) 2005]


25. Among the biotic components of the ecosystem, the producer system is –

(a) Cow
(b) Peacock
(c) Tiger
(d) Green Plants

[U.P.P.C.S. (Pre) 2013]


26. Trophic level-I includes –

(a) Herbivorous animals
(b) Carnivorous animals
(c) Omnivorous animals
(d) Green plants

[M.P.P.C.S. (Pre) 2016]


27. What is true about ecosystems?

(a) Primary consumers are least dependent upon the producer
(b) Primary consumers are out-number producers
(c) Producers are more than primary consumers
(d) Secondary consumers are the largest and most powerful

[U.P.P.C.S. (Pre) 2019]


28. Which one of the following pairs is correctly matched?

(a) Mountain – Most stable ecosystem
(b) Abiotic Component – Bacteria
(c) Green plants – Ecosystem
(d) Rainfall – Global Warming

[U.P.P.C.S. (Pre) 2015]


29. The correct order in the food chain of the various components of a terrestrial grass ecosystem is –

(a) Grass, Grasshopper, Frog, Snake
(b) Grass, Grasshopper, Snake, Frog
(c) Grasshopper, Frog, Grass, Snake
(d) Grasshopper, Snake, Frog, Grass

[U.P.P.S.C. (GIC) 2010]


30. Which of the following constitutes a food chain?

(a) Grass, wheat and mango
(b) Grass, goat and human
(c) Goat, cow and elephant
(d) Grass, fish and goat
(e) None of the above

[Chhattisgarh P.C.S. (Pre) 2016, Chhattisgarh P.C.S. (Pre) 2015]


31. The pyramid of energy in any ecosystem is

(a) Always upright
(b) May be upright and inverted
(c) Always inverted
(d) None of the above

[M.P.P.C.S. (Pre) 2020]


32. Biomass Pyramid is reversed in which type of ecosystem?

(a) Forest
(b) Pond
(c) Grassland
(d) Drylands

[U.P.P.S.C. (GIC) 2010]


33. An inverted pyramid of biomass can be found in which ecosystem?

(a) Marine
(b) Grassland
(c) Forest
(d) Tundra

[R.A.S./R.T.S. (Pre) 2021]


34. Which one of the following organisms is likely to show the highest concentration of DDT, once it has been introduced into the ecosystem?

(a) Grasshopper
(b) Toad
(c) Snake
(d) Cattle

[I.A.S. (Pre) 1997]


35. The amount of energy during the transfer from one trophic level to another in an eco-system–

(a) Increases
(b) Decreases
(c) Remains constant
(d) May increase or decrease

[U.P. R.O./A.R.O. (Pre), 2017]


36. The amount of energy during the transfer from one trophic level to another in an ecosystem–

(a) Increases
(b) Decreases
(c) Remains constant
(d) May increase or decrease

[U.P.P.C.S. (Pre) 2019]


37. Which one of the following trees is not eco-friendly?

(a) Babul
(b) Eucalyptus
(c) Neem
(d) Pipal

[U.P. U.D.A./L.D.A. (Mains) 2010, U.P.P.C.S. (Mains) 2011]


38. The example of “Lentic Habitat” in the freshwater community is:

(a) Ponds and swamps
(b) Waterfalls and rivers
(c) Ponds and rivers
(d) All the above.

[MP.P.C.S. (Pre) 2014]


39. The transitional zone between two distinct communities is known as:

(a) Ecotype
(b) Arcade
(c) Ecosphere
(d) Ecotone

[U.P.P.C.S.(Pre) 2012]


40. Which of the following is the most stable ecosystem?

(a) Desert
(b) Mountain
(c) Ocean
(d) Forest

[U.P.P.C.S. (Pre) 2013]


41. Which of the following is an example of an anthropogenic biome?

(a) Fresh water
(b) Grassland
(c) Rain forest
(d) Cropland

[U.P. P.C.S. (Pre) 2018]


42. Consider the following statements:

1. Most of the world’s coral reefs are in tropical waters.
2. More than one-third of the world’s coral reefs are located in the territories of Australia, Indonesia, and the Philippines.
3. Coral reefs host far more animal phyla than those hosted by tropical rainforests.

Which of the statements given above is/are correct?

(a) 1 and 2 only
(b) 3 only
(c) 1 and 3 only
(d) 1, 2 and 3

[I.A.S. (Pre) 2018]


43. Which one of the following is the largest ecosystem of the earth?

(a) Hydrosphere
(b) Biome
(c) Lithosphere
(d) Biosphere

[U.P. R.O./A.R.O. (Pre) 2017]


44. The cycling of elements in an ecosystem is called:

(a) Chemical cycles
(b) Biogeochemical cycles
(c) Geological cycles
(d) Geochemical cycles

[U.P.P.C.S.(Pre) 2012]


45. In the case of which one of the following biogeochemical cycles, the weathering of rocks is the main source of release of nutrients to enter the cycle?

(a) Carbon cycle
(b) Nitrogen cycle
(c) Phosphorus cycle
(d) Sulphur cycle

[I.A.S (Pre) 2021]


46. The movement of nutrient elements through various components of an ecosystem is called:

(a) Bio-geo-chemical cycle
(b) Bio-geological cycle
(c) Ecological succession
(d) Biological cycle

[U.P.P.C.S. (Pre) 2020]


47. Which one of the following is not related to ecological balance?

(a) Water management
(b) Afforestation
(c) Industrial Management
(d) Wildlife protection

[U.P.P.C.S. (Pre) 2005]


48. “Ecology is permanent economy” is the slogan of which movement?

(a) Appiko Movement
(b) Narmada Bachao Andolan
(c) Chipko Movement
(d) None of the above

[U.P.P.C.S. (Mains) 2007]


49. Chipko movement is related to:

(a) Plant conservation
(b) Tiger project
(c) Crocodile conservation
(d) Plant reproduction

[U.P.P.C.S. (Pre) 2015]


50. Consider the following statements relating to the ecosystem:

1. The term ecosystem was first used by A.G. Tansley.
2. Those organisms which produce their food themselves are termed autotrophs.
3. Consumers consume their food through the process of photosynthesis.
4. Decomposers convert inorganic matter into organic matter.

Which of the above statements is correct:


(a) 1 and 2
(b) 1 and 3
(c) 2 and 4
(d) 3 and 4

[U.P.U.D.A./L.D.A. (Pre) 2002]


51. Which one of the following is the correct sequence of ecosystems in the order of decreasing productivity?

(a) Oceans, lakes, grasslands, mangroves
(b) Mangroves, oceans, grasslands, lakes
(c) Mangroves, grasslands, lakes, oceans
(d) Oceans, mangroves, lakes, grasslands

[I.A.S. (Pre) 2013]


52. Concerning food chains in ecosystems, consider the following statements

1. A food chain illustrates the order in which a chain of organisms feeds upon each other.
2. Food chains are found within the population of a species.
3. A food chain illustrates the number of organism, which is eaten by others.

Which of the statements given above is /are correct?

(a) Only 1
(b) 1 and 2
(c) 1, 2 and 3
(d) None of these

[I.A.S. (Pre) 2013]


53. Which of the following statements is correct?

(a) The energy flow in the biospheric ecosystem is unidirectional.
(b) The energy flows in the biospheric is cyclical.
(c) Relative loss of energy in the natural ecosystem decreases with increasing trophic levels.
(d) Species at progressively higher trophic levels appear to be less efficient in using available energy

[U.P.P.C.S. (Pre) (Re. Exam) 2015]



1. Who of the following used the term ‘deep ecology’ for the first time?

(a) E.P. Odum
(b) C. Raunkiaer
(c) F.E. Clements
(d) Arne Naess

[U.P.P.C.S. (Mains) 2014]


2. The concept of the ecological niche was enunciated by –

(a) Grinnell
(b) Darwin
(c) E.P. Odum
(d) C.C. Park

[U.P.P.C.S. (Pre) 2005]


3. The measurement unit of the ecological footprint is:

(a) Global hectares
(b) Nanometer
(c) Hoppus cubic foot
(d) Cubicton

[U.P.R.O./A.R.O. (Pre) 2016]


4. The minimum area of the land required to completely sustain the life of the person is called his –

(a) Biota
(b) Ecological footprint
(c) Biome
(d) Niche

[U.P.P.C.S. (Pre) 2012]


5. Which one of the following statements best describes the term ‘Social Cost of Carbon’? It is a measure, in monetary value, of the:

(a) long-term damage done by a tonne of CO2 emissions in a given year.
(b) requirement of fossil fuels for a country to provide goods and services to its citizens, based on the burning of those fuels.
(c) efforts put in by a climate refugee to adapt to living in a new place.
(d) contribution of an individual person to the carbon footprint on the planet Earth.

[I.A.S. (Pre.) 2020]


6. Read the list of Ecological concerns and the year in which the Acts were executed in India:

Ecological Concerns Year, Act was passed
A. Wildlife Protection  (i) 1986
B. Environment Protection (ii) 2013
C. The Scheduled Tribes and other Traditional forest dwellers (Recognition of Forest Rights) (iii) 1972
D. The Forest Conservation Act (iv) 1988

Which of the following is not correctly matched?


(a) iii i ii iv
(b) iv ii iii i
(c) i ii iii iv
(d) ii iii iv i

[R.A.S./R.T.S.(Pre) 2013]


7. The Millennium Ecosystem Assessment describes the following major categories of ecosystem services, supporting, regulating, preserving, and cultural.

Which one of the following is a supporting service?

(a) Production of food and water
(b) Control of climate and disease
(c) Nutrient cycling and crop pollination
(d) Maintenance of diversity

[I.A.S. (Pre) 2012]


8. Which one of the following is the correct sequence of a food chain?

(a) Diatoms-Crustaceans-Herrings
(b) Crustaceans-Diatoms-Herrings
(c) Diatoms-Herrings-Crustaceans
(d) Crustaceans-Herrings-Diatoms

[I.A.S. (Pre) 2014]


9. Which of the following statements is true about Bionomics?

1. It means “management of life’.
2. It is synonymous with ecology.
3. It stresses the value of natural systems which influence human systems.

Code :

(a) Only 1
(b) 1 and 2
(c) 2 and 3
(d) 1, 2 and 3

[U.P. U.D.A./L.D.A. (Pre) 2001]


10. Which of the following shows a density gradient of the water system?

(a) Ecocline
(b) Halocline
(c) Pycnocline
(d) Thermocline

[U.P.P.C.S. (Mains) 2016]


11. In the context of ecosystem productivity, marine upwelling zones are important as they increase marine productivity by bringing the:

1. Decomposer micro-organisms to the surface.
2. Nutrients to the surface.
3 Bottom-dwelling organisms to the surface.

Which of the statements given above is/are correct?

(a) 1 and 2
(b) 2 only
(c) 2 and 3
(d) 3 only

[I.A.S. (Pre) 2011]


12. Concerning ‘Eco-Sensitive Zones’, which of the following statements is/are correct?

1. Eco-sensitive zones are the areas that are declared under the Wildlife (Protection) Act, of 1972.
2. The purpose of the declaration of Eco-Sensitive Zones is to prohibit all kinds of human activities in those zones except agriculture.

Select the correct answer using the code given below:

(a) 1 only
(b) 2 only
(c) Both 1 and 2
(d) Neither 1 nor 2

[I.A.S. (Pre) 2014]


13. Given below are two statements, one is labeled as Assertion (A) and the other as Reason (R).

Assertion (A): Various components of an ecosystem are not interdependent.
Reason (R): Human activities have an impact on the environment.

Choose the correct answer from the code given below.


(a) Both (A) and (R) are true, and (R) is the correct explanation of (A).
(b) Both (A) and (R) are true, and (R) is not the correct explanation of (A).
(c) (A) is true, but (R) is false.
(d) (A) is false, but (R) is true.

[U.P.R.O./A.R.O. (Mains) 2016, U.P.P.C.S. (Pre) 2021]


14. In the grassland, trees do not replace the grasses as a part of an ecological succession because of:

(a) Insects and fungi
(b) Limited sunlight and paucity of nutrients
(c) Water limits and fire
(d) None of the above

[I.A.S. (Pre) 2013]


15. The concept of ‘Ecological Transition’ was first used by:

(a) Elton
(b) Bennett
(c) Berkeley
(d) Ratzel

[U.P.P.C.S. (Pre) 2020]


16. The entire sequence of communities that successively change in a particular area are called:

(a) Ecological succession
(b) Sere
(c) Community dynamics
(d) Pyramid of biomass

[U.P.P.C.S. (Pre) 2020]


17. Which one of the following is the correct sequence of the phases of biotic succession?

(a) Nudation, Migration, Ecesis, Reaction, Stabilization
(b) Migration, Nudation, Ecesis, Reaction, Stabilization
(c) Ecesis, Migration, Nudation, Reaction, Stabilization
(d) Stabilization, Reaction, Nudation, Migration, Ecesis

[U.P.P.C.S. (Mains) 2016]


18. Which one of the following is the correct order of biological organization ranging from organism to biosphere?

(a) Population- Ecosystem- Community – Landscape
(b) Landscape- Community-Ecosystem-Population
(c) Population – Community- Ecosystem- Landscape
(d) Population- Landscape- Community- Ecosystem

[U.P.P.C.S. (Pre) 2017]


19. Consider the following statements about the eco-system:

1. The production at the autotroph level is said to be primary productivity.
2. The secondary productivity refers to the production at the heterotroph level.

Of the above, the correct statement is/are:

(a) Only 1
(b) Only 2
(c) Both 1 and 2
(d) Neither 1 and 2

[U.P. R.O./A.R.O. (Pre) 2017]


20. Which of the following is the correct sequence of ecosystem in order of decreasing productivity?

(a) Ocean, Lakes, Grasslands and Mangroves
(b) Mangroves, Oceans, Grasslands and Lakes
(c) Mangroves, Grasslands, Lakes and Oceans
(d) Oceans, Mangroves, Lakes and Grasslands

[U.P.R.O./A.R.O. (Pre) 2021]