2023 Environment, Science and Technology Prelims PYQs

For UPSC aspirants, analyzing Environment and Science & Technology Prelims PYQs (Previous Years’ Questions) is a crucial step to mastering these dynamic and high-yield sections of the Prelims exam. These questions reveal important trends, recurring topics, and key concepts that are frequently tested, helping candidates align their preparation with exam requirements. Reviewing Environment and Science & Technology Prelims PYQs from recent years, including 2023, allows aspirants to focus on topics such as Biodiversity, Climate Change, Conservation Initiatives, International Agreements, Biotechnology, Artificial Intelligence, Space and Defense Technologies, and Health Innovations.

In this post, we’ll provide an in-depth analysis of the 2023 Environment and Science & Technology Prelims PYQs, highlighting question types, emerging patterns, and critical areas to prioritize. This guide will equip you with the insights needed to tackle these questions effectively, boosting your overall preparation for the UPSC Prelims.



1. Consider the following actions:
  1. Detection of car/collision which results in the deployment of airbags almost instantaneously
  2. Detection of accidental free fall of a laptop towards off of the hard drive
  3. Detection of the tilt of the smart phone which results in the rotation of display between potrait and landscape mode

In how many of the above actions us the function od accelerometer required?

  1. Only one
  2. Only two
  3. All three
  4. None


2. Consider the following:
  1. Aerosols
  2. Foam agents
  3. Fire retardants
  4. Lubricants

In the making of how many of the above are hydroflurocarbons used?

  1. Only one
  2. Only four
  3. Only three
  4. All four


3. Consider the following statements:
  1. Carbon fibres are used in the manufacture of the components used in automobiles and aircrafts.
  2. Carbon fibres once used cannot be recycled.

Which of the statements given above is/are correct?

  1. 1 only
  2. 2 only
  3. Both 1 and 2
  4. Neither 1 nor 2


4. Consider the following statements:
  1. Some mushrooms have medicinal properties.
  2. Some mushrooms havr psychoactive properties.
  3. Some mushrooms have insecticidal properties.
  4. Some mushrooms have bioluminescent properties.

How many of the above statements are correct?

  1. Only one
  2. Only two
  3. Only three
  4. All four


5. ‘Wolbachia method’ is sometimes talked about with reference to which one of the following?
  1. Controlling the viral diseases spread by mosquitoes
  2. Converting crop residues into packing material.
  3. Producing biodegradble plastics.
  4. Producing biochar from thermochemical conversion of biomass.


6. With reference to green hydrogen, consider the following statements:
  1. It can be used directly as a fuel for internal combustion.
  2. It can be blended with natural gas and used as fuel for heat or power generation.
  3. It can be used in the hydrogen fuel cell to run vehicles.

How many of the above statements are correct?

  1. Only one
  2. Only two
  3. All three
  4. None


7. With reference to coal-based thermal power plants in India, consider the following statements:
  1. None of them uses seawater.
  2. None of them is set up in water-stressed district.
  3. None of them is privately owned.

How many of the above statements are correct?

  1. Only one
  2. Only two
  3. All three
  4. None


8. Which one of the following is the best example of repeated falls in sea level, giving rise to present-day extensive marshland?
  1. Bhitarkanika Mangroves
  2. Marakkanam Salt Pans
  3. Naupada Swamp
  4. Rann of Kutch


9. Consider the following statements:

Statement-I: Marsupials are not naturally found in India.

Statement-II: Marsupials can thrive only in montane grasslands with no predators.

Which one of the following is correct in respect of the above statements?

  1. Statement-I and Statement-II are correct and Statement-II explains Statement-I
  2. Both Statement-I and Statement-II are correct, but Statement-II does not explain Statement-I
  3. Statement-I is correct, but Statement-II is incorrect
  4. Statement-I is incorrect, but Statement-II is correct


10. Consider the following fauna:
  1. Lion-tailed Macaque
  2. Malabar Civet
  3. Sambar Deer

How many of the above are generally nocturnal or most active after sunset?

  1. Only one
  2. Only two
  3. All three
  4. None


11. Which of the following organisms perform waggle dance for others of their kin to indicate the direction and the distance to a source of their food?
  1. Butterflies
  2. Dragonflies
  3. Honeybees
  4. Wasps


12. Consider the following statements regarding the Indian squirrels:
  1. They build nests by making burrows in the ground.
  2. They store their food materials like nuts and seeds in the ground.
  3. They are omnivorous.

How many of the above statements are correct?

  1. Only one
  2. Only two
  3. All three
  4. None


13. Consider the following statements:
  1. Some microorganisms can grow in environments with temperature above the boiling point of water.
  2. Some microorganisms can grow in environments with temperature below the freezing point of water.
  3. Some microorganisms can grow in highly acidic environment with a pH below 3.

How many of the above statements are correct?

  1. Only one
  2. Only two
  3. All three
  4. None


14. Which one of the following makes a tool with a stick to scrape insects from a hole in a tree or a log of wood?
  1. Fishing cat
  2. Orangutan
  3. Otter
  4. Sloth bear


15. Consider the following statements:
  1. In India, the Biodiversity Management Committees are key to the realization of the objectives of the Nagoya Protocol.
  2. The Biodiversity Management Committees have important functions in determining acces and benifit sharing, including the power to levy collection fees on the access of biological resources within its jurisdiction.

Which of the statements given above is/are correct?

  1. 1 only
  2. 2 only
  3. Both 1 and 2
  4. Neither 1 nor 2


16. Invasive Species Specialist Group (that develops Global Invasive Species Database) belongs to which one of the following organizations?
  1. The International Union for Conservation of Nature
  2. The United Nations Environment Progranne
  3. The United Nations World Commission for Environment and Development
  4. The World Wide Fund for Nature


17. Consider the following statements:

Once the Central Government notifies an area as a ‘Community Reserve’

  1. the cheif Wildlife Warden of the State becomes the governing authority of such forest.
  2. hunting is not allowed in such area.
  3. people of such area are allowed to collect non-timber forest produce.
  4. people of such area are allowed traditional agricultural practices.

How many of the above statements are correct?

  1. Only one
  2. Only two
  3. Only three
  4. All four


18. Consider the following statements:

Statement-I:

Statement-II:

Which one of the following is correct in respect of the above statements?

  1. Statement-I and Statement-II are correct and Statement-II explains Statement-I
  2. Both Statement-I and Statement-II are correct, but Statement-II does not explain Statement-I
  3. Statement-I is correct, but Statement-II is incorrect
  4. Statement-I is incorrect, but Statement-II is correct


19. Consider the following statements regarding mercury pollution:
  1. Gold mining activity is a source of mercury in the world.
  2. Coal-based thermal power plants cause mercury pollution.
  3. There is no known safe level of exposure to mercury.

How many of the above statements are correct?

  1. Only one
  2. Only two
  3. All three
  4. None


20. Consider the following activities:
  1. Spreading finely ground basalt rock on farmlands extensively.
  2. Increasing the alkanity oceans by adding lime.
  3. Capturing carbon dioxide released by various industries and pumping it into abandoned subterranean mines in the form of carbonated waters.

How many of the above activities are often considered and discussed for carbon capture and sequestration?

  1. Only one
  2. Only two
  3. All three
  4. None


21. With reference to the role of biofilters in Recirculating Aquaculture System, consider the following statements:
  1. Biofilters provide waste treatment by removing uneaten fish feed.
  2. Biofilters convert ammonia present in fish waste to nitrate.
  3. Biofilters increase phosphorus as nutrient for fish in water.

How many of the statements given above are correct?

  1. Only one
  2. Only two
  3. All three
  4. None


22. Consider the following pairs:
Object in space Description
Cepheids Giant clouds of dust and gas in space
Nebulae Stars which brighten and dim periodically
Pulsars Neutron stars that are formed when massive stars run out of fuel and collapse.

How many of the above pairs are correctly matched?

  1. Only one
  2. Only two
  3. All three
  4. None


23. Which one of the following countries has its own Satellite Navigation System?
  1. Australia
  2. Canada
  3. Israel
  4. Japan


24. ‘Aerial metagenomics’ best refers to which one of the following situations?
  1. Collecting DNA samples from air in a habitat at one go
  2. Understanding the genetic makeup of avian species of a habitat
  3. Using air-borne devices to collect blood samples from moving animals
  4. Sending drones to inaccessible areas to collect plant and animal samples from land surfaces and water bodies.


25. ‘Microsatellite DNA’ is used in the case of which one of the following?
  1. Studying the evolutionary relationships among various species of fauna
  2. Stimulating ‘stem cells’ ti transform into diverse functional tissues
  3. Promoting clonal propagation of horticultural plants
  4. Assessing the efficacy of drugs by conducting series of drug trials in a population


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