Environment and Ecology Mixed Practice — MCQs with Answers (Set 1)

The Punjab government launched ‘Shaheed-e-Azam Sardar Bhagat Singh Hariawal Lehar’, an afforestation drive planting saplings across the state’s assembly segments, named after freedom fighter Bhagat Singh.

Statement 1 is wrong: cold, clear water with low nutrients describes oligotrophic (young) lakes, not eutrophic ones. Statement 2 is the correct definition — eutrophication is caused by excess nutrients like nitrogen and phosphorus.

India averages 5 to 6 tropical cyclones a year, not 12 to 15, and they form in the pre- and post-monsoon seasons, not continuously. Only statement 1, on the Bay of Bengal’s higher frequency, is correct.

The correct answer is textile fibre. Himalayan nettle’s stem yields a strong bast fibre, called allo in Nepal, that is hand-spun into cloth.

The correct answer is Neyyar, Peppara and Shendurney Wildlife Sanctuaries (Kerala), plus Kalakad Mundanthurai Tiger Reserve (Tamil Nadu). These four protected areas together make up Agasthyamala Biosphere Reserve.

Correct answer: (D) Waste-to-energy technologies. Pyrolysis heats waste in the absence of oxygen, and plasma gasification uses ionised gas at extreme heat. Both convert waste into syngas instead of burning it, so they are waste-to-energy technologies.

The correct answer is (a) The European Union. The EU’s Nature Restoration Law (Regulation (EU) 2024/1991) was formally adopted in June 2024 and entered into force on 18 August 2024. It requires member states to restore at least 20% of the EU’s degraded land and sea areas by 2030, and all ecosystems needing restoration by 2050. The law supports both EU climate targets and the Kunming-Montreal Global Biodiversity Framework.

All three items contain plastic. Cigarette filters are made of cellulose acetate, a synthetic polymer classed as a plastic. Most modern eyeglass lenses use plastics such as CR-39 or polycarbonate, not glass. Car tyres contain synthetic rubber, a plastic-family polymer — and tyre wear is a major, often-overlooked source of microplastic pollution.

The answer is (a). Article 6.2 and 6.4 set up carbon markets, so Statement II is right. Article 6.8 promotes non-market cooperation, so Statement III is right. Both are part of why Article 6 is discussed, so both explain Statement I. Options (b), (c) and (d) each wrongly drop one or both. Memory hook: 6.2 pairs, 6.4 pools, 6.8 shares.

Orangutans strip the leaves off a stick and use the resulting tool to scrape insects out of a hole in a tree or a log of wood — a well-documented example of toolmaking in a non-human primate.

Indian squirrels build nests in trees, not by burrowing into the ground, so Statement 1 is false. They do store food like nuts and seeds in the ground (Statement 2, true), and they are omnivorous (Statement 3, true) — so 2 of 3 statements are correct.

The Congo Basin spans six countries: Cameroon, the Central African Republic, the Republic of Congo, the Democratic Republic of Congo, Equatorial Guinea, and Gabon. Nigeria, South Sudan, and Uganda are not among them.

Mahua and teak are both deciduous trees, common in India’s tropical deciduous forests, shedding their leaves in the dry season. Jackfruit is an evergreen tree, retaining its leaves year-round.

Only statement II is correct. Marine phytoplankton and bacteria make about half of the oxygen produced on Earth. Statement I is false because the ocean makes more than land forests. Statement III is false because water holds far less oxygen than air.

Statement 1 is false — the Gooty tarantula is a spider (arachnid), not a crustacean. Statement 2 is correct — its natural habitat in India is limited to only a small forest area in Andhra Pradesh. Statement 3 is correct — in its natural habitat it is arboreal, living in tree holes and bark crevices.

All three statements are correct. DAC can be used for carbon sequestration (permanent underground storage). Captured CO2 is a valuable industrial feedstock, used to produce some plastics and purified to food/beverage-grade CO2. And in aviation, captured CO2 can combine with hydrogen to create synthetic low-carbon fuel.

A Membrane Bioreactor integrates the activated sludge biological process with membrane filtration, replacing the secondary clarifier and producing high-quality, reusable treated water.

All four are recognised feedstocks for Sustainable Aviation Fuel (SAF). Agricultural residues (like straw and corn stover) and corn grain can be converted via processes like alcohol-to-jet. Wastewater treatment sludge and wood mill waste are also usable biomass feedstocks in various SAF production pathways. SAF aims to cut aviation’s carbon footprint by using waste and biomass instead of fossil jet fuel. The answer is (c) 1, 2, 3 and 4.

The Indian Flying Fox was once placed under the vermin category. It is a frugivore, feeding on fruit, nectar, and flowers, not blood — blood-feeding is a vampire-bat trait, and vampire bats do not occur in India.

Carabid beetles, flies, and wasps all include genuine parasitoid species. Centipedes are predators, not parasitoids, and termites have no known parasitoid species.

All three statements are correct. PFAS are widespread in drinking water, food, and packaging materials, resist environmental degradation due to their strong carbon-fluorine bond, and bioaccumulate in animal tissue with persistent exposure.

The Cuvette Centrale, in the central Congo Basin, is the world’s largest tropical peatland complex, storing about 30 billion tonnes of carbon — roughly three years of global fossil-fuel emissions.