UPSC 2012 Environment & Ecology PYQs with Answers

The sharp decline of vultures in India is attributed mainly to diclofenac, a veterinary drug used in cattle. Vultures feeding on carcasses of treated cattle suffered fatal kidney failure.

Phytoplankton absorb carbon dioxide through photosynthesis and form the base of marine food chains. Their destruction would harm ocean carbon uptake and food webs, but would not drastically decrease ocean-water density.

Zero tillage reduces soil disturbance and helps retain organic carbon in soil. The official key treats it as the carbon-sequestration practice among the listed options.

Black-necked crane, flying squirrel and snow leopard are naturally found in India. The cheetah was not naturally extant in India at the time of this question, so it is excluded by the official key.

Global warming, habitat fragmentation and invasive alien species are major biodiversity threats. Promotion of vegetarianism is not a biodiversity threat in this context.

Supporting services are underlying ecosystem processes such as nutrient cycling and soil formation that support other services. Nutrient cycling fits this category; crop pollination is also treated as an ecosystem function in the given option.

Great Indian Bustard, Musk Deer, Red Panda and Asiatic Wild Ass are all threatened/endangered species categories in Indian conservation discussions. The other sets include common or less-threatened species such as chital, nilgai, rhesus monkey or langur.

Bats, bees and birds all act as pollinators for different plant species. Bees are the most familiar, while bats and birds pollinate many night-blooming or nectar-rich flowers.

Bt brinjal concerns centred on possible health risks and biodiversity impacts. The inserted gene is from Bacillus thuringiensis, a bacterium, not a fungus, and Bt brinjal was not a terminator-seed technology.

Life is based primarily on carbon compounds with hydrogen and nitrogen as essential elements of biomolecules such as proteins and nucleic acids. Sodium, calcium and potassium are important ions but not the primary origin-of-life set here.

Ocean acidification reduces carbonate ion availability, harming calcareous plankton, corals and organisms with calcifying larvae or planktonic larval stages. It is not a direct concern for cloud seeding or cloud formation in this question.

Sea buckthorn helps control erosion/desertification and is nutritionally valuable, especially in cold high-altitude regions. It is not mainly promoted for rich biodiesel yield or commercial timber.

Biopesticides include bacteria such as Bacillus thuringiensis, fungi such as Beauveria, and plant-derived pest-control agents from flowering plants such as neem. Hence all three categories are used.

The NBA protects India's biological resources and traditional knowledge by regulating access and checking biopiracy. IPR applications involving Indian biological resources require NBA approval; it does not directly supervise all GM crop research.