Ecology And Environment

21 Questions MCQ Test | Ecology And Environment

This mock test of Ecology And Environment for UPSC helps you for every UPSC entrance exam. This contains 21 Multiple Choice Questions for UPSC Ecology And Environment (mcq) to study with solutions a complete question bank. The solved questions answers in this Ecology And Environment quiz give you a good mix of easy questions and tough questions. UPSC students definitely take this Ecology And Environment exercise for a better result in the exam. You can find other Ecology And Environment extra questions, long questions & short questions for UPSC on EduRev as well by searching above.

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


Explanation: Productivity is the production of new biomass by an ecosystem.
Different ecosystem have different rate of productivity which depend on various factors like water, nutrients, temperature etc.
In the given ecosystems mangrove have highest productivity due to it having high species richness as it represents ecotone between terrestrial and marine ecosystem. Then comes the grasslands which represents ecotone between tropics and desert but less productive than mangroves due to low moisture content.
Lake comes third as its productivity various on level of nutrients with eutrophic being more productive. Oceans are least among the four inspite of being large in area because only up to 250 m of ocean is productive where sunlight is available called photic zone.
Hence option c is the right sequence
Educational Objective: To study salient features of different ecosystems and evaluating their contribution to world biomass.


In the context of ecosystem productivity, marine upwelling zones are important as they increase the marine productivity by bringing the
1) Decomposer microorganisms to the surface.
2) Nutrients to the surface.
3) Bottom-dwelling organisms to the surface.
Which of the statements given above is/are correct?


Explanation: Marine upwelling zones are one of the most productive fishing grounds in the world (Japanese coast, Newfoundland) because in this zone the hot waters are replaced by the lower cold waters due to tidal action which bring the vast nutrients from ocean deep to the surface enhancing species richness and productivity..

  • Statements 1 and 3 are incorrect because microorganisms at surface decreases oxygen creating abnoxic conditions and consequently dead zones. Bringing organisms from depth increases competition resulting in declining productivity.

Educational Objective: To understand why only some locations are the largest fishing grounds in the world and reasons for their distribution.


Which of the following leaf modifications occurs/occur in desert areas to inhibit water loss?
1) Hard and waxy leaves
2) Tiny leaves or no leaves
3) Thorns instead of leaves
Select the correct answer using the codes given below.


Explanation: The plants in desert survive the extreme climates by xerophytic adaptations which includes various modification in roots, stem and leaves. Modification of leaves is the frequent adaptation

  • Hard and waxy leaves prevent excess transpiration and also protects leaves from direct heat of sun
  • Tiny leaves and thorny leaves also regulate excess transpiration and also inturn protects plants from cattle. ·
  • Hence all are helpful for survival of plants in desert climate

Educational Objective: To understand how fauna and flora survive in extreme desert conditions.


The Millennium Ecosystem Assessment describes the following major categories of ecosystem services- provisioning, supporting, regulating, preserving and cultural. Which one of the following is supporting service?


Explanation: Supporting services are the services which are responsible for production of all other ecosystem services, hence option c is correct as nutrient cycling and pollination helps in production of food which is a provisioning service of ecosystem.

  • Control of climate and disease is a regulating service as it regulates the ecosystem processes.
  • Maintenance of diversity is a cultural service as it increases species richness and in turn creates recreational value.

Educational Objective: To understand the importance of ecosystem in the day today life of human beings.


Which one of the following is the best description of the term ‘Ecosystem'?


Explanation: Option a is incorrect as it is missing the abiotic component i.e environment

  • Part of earth on which we live is biosphere hence option b also incorrect.
  • Option c is the best and most complete definition of ecosystem (interaction between the biotic (living organisms) and abiotic (Soil, climate etc)).

Educational Objective: To understand different ecological terms like ecology, ecosystem, ecotone etc., and differentiate them.


Which one of the following terms describes not only the physical spaceoccupied by an organism, but also its functional role in the community of organisms?


Ecological Niche refers to the unique functional role and position of a species in its habitat or ecosystem. A niche can also be described as the interactions, a species has with its biotic and abiotic environment. Hence, option B is correct.
Ecotone is a zone of junction or a transition area between two biomes (diverse ecosystems). Habitat is the place or environment where a plant or animal naturally or normally lives and grows.
Educational Objective: To know about important ecological terms such as Ecological niche, Ecotone, Habitat etc.,


With reference to the wetlands of India, consider the following statements:
1) The country's total geographical area under the category of wetlands is recorded more in Gujarat as compared to other States.
2) In India, the total geographical area of coastal wetlands is larger than that of inland wetlands.
Which of the statements given above is/are correct?


Explanation: Wetlands are areas intermediate in character between deep water and terrestrial habitats, also transitional in nature, and often located between them.

  • Gujarat has largest wetland area followed by Andhra  Pradesh, Uttar Pradesh, west Bengal and Maharashtra in top five. ·
  • Coastal wetlands occupy more than 50% of wetlands in India prominent among them are chilika lake ( Orissa), Pulicatetc

Educational Objective: To study wetland distribution in India and it’s ecological importance.


Consider the following statements
1. Under Ramsar convention, it is mandatory on the part of the Government of India to protect and conserve all the wetlands in the territory of India.
2. The Wetlands (Conservation and Management) Rules, 2010 were framed by the Government of India based on the recommendations of Ramsar convention.
3. The Wetlands (Conservation and Management) Rules, 2010 also encompass the drainage area or catchment regions of the wetlands as determined by the authority.
Which of the statements given above is/are correct?


Explanation: The Convention on Wetlands [waterfowl convention] is an intergovernmental treaty that provides the framework for national action and international cooperation for the conservation and wise use of wetlands and their resources.

  • Statement 1 is not correct as it is mandatory to protect at least wetlands of international importance and is voluntary on part of government with respect to other wetlands.
  • Statement 2 is incorrect as rules are made independent of Ramsarconvention for regulating various activities with respect to all wetlands in the country.
  • Hence statement 3 is only correct answer as wetland rules 2010 have been made stringent by encompassing the drainage and catchment areas of wetlands.

Educational Objective: To study wetlands and related rules and convention like Ramsar convention which is only convention for wetland protection.


With reference to a conservation organization called ‘Wetlands International’, which of the following statements Is/are correct?
1) It is an intergovernmental organization formed by the countries which are signatories to Ramsar Convention.
2) It works at the field level to develop and mobilize knowledge, and use the practical experience to advocate for better policies.
Select the correct answer using the codes given below.


Explanation: Statement 1 in incorrect because wetlands International is a not for profit organization working in the field of wetland conservation.

  • Wetlands International’s work ranges from research to community based field projects to advocacy and engagement with governments corporates and various conventions.

Educational Objective: To study about various organization associated with wetland protection and management.


Consider the following pairs
1. Harike Wetlands
2. Keoladeo Ghana
3. Kolleru Lake
Confluence of rivers
: Confluence of Beas and Satluj/Sutlej
: Confluence of National Park Banas and Chambal
: Confluence of Musi and Krishna
Which of the above pairs is / are correctly matched?


Explanation: Harike wetland also called “Harike-Pattan” is the largest wetland in north India constructed in 1953 by erecting headworks at the confluence of Beas and Sutlej just south of Harike village.

  • Keoladeo Ghana National Park is a man made wetland and one of national parks in India. Initially it was a depression which was flooded to form wetland when Maharaja constructed Arjun Bund at the confluence of rivers Gambhir and Banganga in 1750s. In 1985 the park was declared world heritage convention.
  •  Kollerulake is one of the largest fresh water lake in India and largest shallow water lake between deltas of Krishna and Godavari.
    Hence only the first option is correctly matched.

Educational Objective: To know the geography and features of wetlands of International Importance in India.


If a wetland of international importance is brought under the 'Montreux Record', what does it imply?


Explanation: Montreux Record is the principal tool under the Ramsar Convention, is a register of wetland sites on the List of Wetlands of International Importance It highlights those sites where adverse changes in ecological character have occurred, are occurring, or are likely to occur as a result of technological developments, pollution or other human interference and which are therefore in need of priority conservation attention. It is maintained as part of the Ramsar List. Montreux Record are employed to identify priority sites for positive national and international conservation attention. Sites may be added to and removed from the Record only with the approval of the Contracting Parties in which they lie.
Wetlands from India in Montreux record: Loktaklake and Keoladeo national park
Educational Objective: To know about the wetlands in montreux record from India and steps taken to address the issues with them.


India is a party to the Ramsar Convention and has declared many areas as Ramsar Sites. Which of the following statements best describes as to how we should maintain these sites in the context of this Convention?


Explanation: The Ramsar Convention’s aim is to develop and maintain an international network of wetlands which are important for the conservation of global biological diversity and for sustaining human life through the maintenance of their ecosystem components, processes and benefits.
The Ramsar Convention is an international treaty for the conservation and wise use of wetlands.

  • It is named after the Iranian city of Ramsar, on the Caspian Sea, where the treaty was signed on 2 February 1971.
  • Known officially as ‘the Convention on Wetlands of International Importance especially as Waterfowl Habitat’ (or, more recently, just ‘the Convention on Wetlands’), it came into force in 1975.

What would happen if phytoplankton of an ocean is completely destroyed for some reason?
1) The ocean as a carbon sink would be adversely affected.
2) The food chains in the ocean would be adversely affected.
3) The density of ocean water would drastically decrease.
Select the correct answer using the codes given below:


Explanation: Phyto-planktons are the primary producers of the ocean ecosystem and form the base of food chain.

  • Phyto-planktons being the primary producers absorb great quantity of carbondi-oxide from the atmosphere for photosynthesis, thus acting as carbon sink.
  • Thus complete destruction of Phytoplanktons affect the ocean as carbon sink and also food chain will be affected destroying the entire ocean ecosystem. Hence statement 1 and 2 are correct.
  • Statement 3 is wrong as density of ocean water is dependent on the amount of dissolved salts and rate of evaporation.

Education Objectives: studying the basic building blocks of ocean ecosystem the phyto planktons.


There is a concern over the increase in harmful algal blooms in the seawaters of India. What could be the causative factors for this phenomenon?
1) Discharge of nutrients from the estuaries.
2) Run-off from the land during the monsoon.
3) Upwelling in the seas.
Select the correct answer from the codes given below:


Explanation: Algal blooms are the excessive growth of microscopic algae due to addition of nutrients which as a catalyst for multiplying algae. Most algal blooms are not harmful but some produce toxins and do affect fish, birds, marine mammals and humans. The toxins may also make the surrounding air difficult to breathe. These are known as Harmful Algal Blooms (HABs).

  • Runoff from the land during monsoon may empty muddy water into sea but it may not lead to algal growth as it may not contain the nutrients required for there growth. Hence statement 2 is incorrect.
  • Upwelling of seas bring the nutrients to the surface increasing productivity of marine organisms. Hence statement 3 is also incorrect.

Education Objectives: Studying the concept of eutrophication and it effect on algal bloom.


Which of the following adds/add carbon dioxide to the carbon cycle on the planet Earth?
1) Volcanic action
2) Respiration
3) Photosynthesis
4) Decay of organic matter
Select the correct answer using the code given below.


Explanation: Volcanic action is the eruption of interior of the earth in the form of magma during such various gases like SO2, Carbon-di-oxide are released into atmosphere.

  • Respiration is the process of breathing by living organisms which release carbon-dioxide and intake oxygen for their metabolic activities.
  • Photosynthesis is the ultimate producer of food for all living organisms by the primary producers which produce glucose by consuming carbon-di-oxide and releasing oxygen in the process.
  • Decaying of organic matter release co2 which is stored as biomass during the life of the organism.
  • Thus option 1, 2 and 4 are process responsible for releasing co2 back into carbon cycle.

Education Objectives: Understanding the concept of carbon cycle


Human activities in the recent past have caused the increased concentration of carbon dioxide in the atmosphere, but a lot of it does not remain in the lower atmosphere because of
1) Its escape into the outer stratosphere.
2) The photosynthesis by phytoplankton in the oceans
3) The trapping of air in the polar ice caps.
Which of the statements given above is/ are correct?


Explanation: Statement 1 is incorrect because carbon-di-oxide is found only upto 90 km from earth surface and does not extend to outer stratosphere.

  • Phyto planktons are the primary producers of marine ecosystem and they absorb great amount of co2 for their photosynthesis from the lower atmosphere hence co2 in lower atmosphere is readily absorbed by them decreasing their quantity and acting as lungs. Hence statement 2 is correct.
  • Trapping of air in polar ice caps contain large amount of co2 of historic emissions and not recent ones hence statement 3 is incorrect.

Educational Objective: To study about various methods of Carbon sequestration and role played by Phyto planktons in it.


With reference to food chains in ecosystems, consider the following statements:
1) A food chain illustrates the order in which a chain of organisms feed upon each other
2) Food chains are found within the populations of aspecies
3) A food chain illustrates the number of each organism which are eaten by others
Which of the statements given above is/are correct?


Explanation: Food chain represents the sequence of eaten and being eaten hence statement 1 is correct.

  • Food chain represents the entire sequence of organisms from primary producers to tertiary consumers of different species. Ex: Plant-caterpillar-lizard-snake Hence statement 2 is incorrect.
  • Food chain indicates only the source and direction of flow of energy and not the number of organisms eaten hence statement 3 is incorrect.

Educational Objective: To understand the flow of energy in an ecosystem through the concept of food chain and food web.


With reference to the food chains in ecosystems, which of the following kinds of organism is/are known as decomposer organism/organisms?
1) Virus
2) Fungi
3) Bacteria
Select the correct answer using the codes given below.


Explanation: Viruses are biological agents that reproduces inside the living cells only and hence they cannot exist without host and hence are not decomposers.

  • Fungi are the primary decomposers in the ecosystem which grow on dead or rotten organic matter as Saprophytes or as parasites in host cell.Ex: molds, mushroom
  • Bacteria are non-chlorophyllous microorganisms which lead saprophytic or parasitic existence mainly. Saprophytic are beneficial and used in many industries.

Educational Objective: To study about saprophytes and role theypaly in cleaning the surroundings.


A pesticide which is a chlorinated hydrocarbon is sprayed on a food crop. The food chain is: Food crop-Rat- SnakeHawk. In this food chain, the highest concentration of the pesticide would accumulate in which one of the following?


Explanation: Bio-magnification is the process of accumulation of pollutants as one moves from lower trophic to higher trophic levels.
Bio-accumulation is the process of increase in concentration of pollutant from environment into first organism in food chain.
In the given list of organisms the food chain sequence is Food-rat-snake-hawk Hence hawk being the tertiary consumers has the highest concentration of pollutant.
Educational Objective: To understand bioaccumulation and bio-magnification and difference between them. 


In the grasslands, trees do not replace the grasses as a part of an ecological succession because of


Explanation: Grasslands represent the ecotone between the tropical forests and deserts. In grasslands tress do not replace grasses because of low moisture and high temperatures which results in frequent fires in grasslands. Insects and fungi also cannot survive in extremes of grasslands.
Hence option 3 is the correct answer.
Educational Objective: To study the fauna and flora of grasslands and features influencing it.


Lichens, which are capable of initiating ecological succession even on a bare rock, are actually a symbiotic association of


Explanation: Lichens represents a group of greyish green plants which grow on rocks, tree trunks, dead wood etc. It represents a symbiotic relation between algae and fungi.

  • In this unique relationship algae manufactures food for fungi and fungi in turn absorbs and retains water which keeps algal cells moist.
  • They are most common in wetlands, rare in streams and rivers and absent in ground water.

Educational Objective: To understand interaction between various organisms for survival and functioning of ecosystem.