Q60. On which date is the International Day for the Preservation of the Ozone Layer observed?
[UPPSC PCS Prelims – GS Paper I (2022)]
(A) 2 October
(B) 16 September
(C) 29 April
(D) 30 January
Answer: (B) 16 September
Explanation: World Ozone Day is marked on 16 September, commemorating adoption of the Montreal Protocol in 1987. The day promotes awareness of protecting stratospheric ozone through control of ozone-depleting chemicals.
2021
Q59. Which material is meant by “blue carbon”?
[UPSC CSE Prelims GS Paper I (2021)]
(A) Carbon stored in oceans and coastal ecosystems
(B) Carbon in farmland only
(C) Carbon inside petroleum reservoirs
(D) Atmospheric carbon only
Answer: (A) Carbon stored in oceans and coastal ecosystems
Explanation: Blue carbon is captured and stored by coastal and marine ecosystems, especially mangroves, seagrasses and tidal marshes. Such habitats can accumulate organic carbon in deep sediments for long periods, making restoration relevant to climate mitigation.
Q58. Which element’s biogeochemical cycle chiefly receives new nutrients through rock weathering?
[UPSC CSE Prelims GS Paper I (2021)]
(A) Carbon
(B) Nitrogen
(C) Phosphorus
(D) Sulphur
Answer: (C) Phosphorus
Explanation: Phosphorus lacks a large atmospheric gaseous phase in its primary cycle. Weathering of phosphate-bearing rocks supplies phosphate to soils and waters, where plants and microbes use it. Sedimentation and geological uplift return material over long timescales.
Q57. The principal marine primary producers among copepods, cyanobacteria, diatoms and foraminifera are which?
[UPSC CSE Prelims GS Paper I (2021)]
(A) Copepods and cyanobacteria
(B) Cyanobacteria and diatoms
(C) Diatoms and foraminifera
(D) Copepods and foraminifera
Answer: (B) Cyanobacteria and diatoms
Explanation: Cyanobacteria and diatoms perform photosynthesis and establish the producer base of many marine food webs. Copepods are generally zooplankton consumers, while foraminifera are protists not broadly classified as primary photosynthetic producers.
Q56. Which combination represents detritivores:
1. Earthworms
2. Jellyfish
3. Millipedes
4. Seahorses
5. Woodlice?
[UPSC CSE Prelims GS Paper I (2021)]
(A) 1, 2 and 4
(B) 2, 3, 4 and 5
(C) 1, 3 and 5
(D) All five
Answer: (C) 1, 3 and 5
Explanation: Earthworms, many millipedes and woodlice feed on dead or decaying organic materials. Jellyfish and seahorses are predominantly animal consumers. Detritivores fragment organic matter and help speed nutrient recycling by microbial decomposers.
Q55. Which groups include organisms capable of symbiosis: cnidarians, fungi and protozoans?
[UPSC CSE Prelims GS Paper I (2021)]
(A) Cnidarians and fungi only
(B) Fungi and protozoans only
(C) Cnidarians and protozoans only
(D) All three
Answer: (D) All three
Explanation: Corals form partnerships with photosynthetic microorganisms, fungi form lichens and mycorrhizae, and numerous protozoans live symbiotically with other organisms. Symbiosis is therefore found across all three groups, including associations with different costs and benefits.
Q54. Which organism is a filter feeder?
[UPSC CSE Prelims GS Paper I (2021)]
(A) Catfish
(B) Octopus
(C) Oyster
(D) Pelican
Answer: (C) Oyster
Explanation: Oysters draw water across their gills and trap suspended plankton and organic particles. This filter-feeding strategy can influence water clarity and nutrient cycling. Catfish, octopuses and pelicans generally obtain food by other methods.
Q53. Which choice matches the UNEP-supported Common Carbon Metric?
[UPSC CSE Prelims GS Paper I (2021)]
(A) Measuring the carbon footprint of building operation
(B) Enabling farm carbon trading
(C) Measuring national carbon output alone
(D) Calculating global fossil-fuel use per second
Answer: (A) Measuring the carbon footprint of building operation
Explanation: The Common Carbon Metric was designed to harmonise measurement of energy consumption and greenhouse-gas emissions associated with building operations. Comparable building metrics help policymakers, facility managers and researchers assess the environmental performance of the built environment.
Q52. Which hazards are associated with copper smelters?
1. Severe carbon monoxide release.
2. Heavy-metal leaching from slag.
3. Sulphur dioxide emission.
[UPSC CSE Prelims GS Paper I (2021)]
(A) 1 and 2 only
(B) 2 and 3 only
(C) 1 and 3 only
(D) All three
Answer: (B) 2 and 3 only
Explanation: Copper processing can produce sulphur dioxide when sulphide ores are roasted or smelted. Poorly managed slag can leach metals into soil or water. Massive carbon monoxide release is not the defining impact in this examination’s combination.
Q51. What does the R2 Code of Practices promote?
[UPSC CSE Prelims GS Paper I (2021)]
(A) Responsible recycling of electronics
(B) Ramsar wetland assessment
(C) Farming on degraded lands
(D) Quarry environmental clearances
Answer: (A) Responsible recycling of electronics
Explanation: R2 stands for Responsible Recycling and provides an industry framework for managing used electronics. It covers environmental, worker-health and data-security considerations, seeking traceable reuse and recycling rather than informal disposal of hazardous electronic components.
