Environment & Ecology Previous Year Questions (PYQ) with Answers – Page 7

Biorock is a method of growing reef structures under the sea with a mild electric current, so that corals can settle and recover.

The golden mahseer is a large freshwater fish, not a bird. The golden mahseer (Tor putitora) lives in fast-flowing rivers of the Himalayan foothills, from the Indus basin to the Brahmaputra.

Gucchi is the morel mushroom, a fungus that grows wild in Himalayan forests, but it is not commercially cultivated. Gucchi (Morchella esculenta) has a honeycomb-like cap and is one of the costliest mushrooms in the world, often selling for tens of thousands of rupees a kilogram.

The 2021 WHO guidelines set PM2.5 at 15 µg/m³ for a 24-hour mean and 5 µg/m³ for the annual mean, and ground-level ozone is a known trigger of asthma attacks.

Kidneys filter waste from the blood, and wetlands likewise filter pollutants out of the water that passes through them.

The Climate Action Tracker is an independent scientific analysis run by research groups, not by any UN body. It is produced mainly by two non-profit research organisations, Climate Analytics and the NewClimate Institute, and has tracked national climate action since 2009.

These gases react with water in the air to form sulphuric and nitric acids, which fall as acid rain. Sulphur dioxide comes mainly from burning coal and oil in power plants and smelters, and nitrogen oxides from vehicle engines and high-temperature furnaces.

This statement is wrong: biogas is renewable, because the cattle dung, crop waste and kitchen waste it is made from are produced again and again.

Renuka Wetland in Himachal Pradesh and Rudrasagar Lake in Tripura are correctly matched; Hokera and Sasthamkotta are not. All four are Ramsar sites.

Flooded paddy fields release methane, and the nitrogen fertiliser used on them releases nitrous oxide, so rice is the main crop source of both gases.

Abiotic components are the non-living parts of an ecosystem, and soil belongs squarely to that list along with sunlight, temperature, water, air, minerals and pH.

The 2030 Agenda has seventeen goals, and space research is not among them; the agenda is concerned with poverty, hunger, health, education, equality, water, energy, work, infrastructure, inequality, cities, consumption, climate, oceans, land, peace and partnerships.

Goal 10 is Reduced Inequalities, which is item 3; Goal 13 is Climate Action, which corresponds to climate change, item 1; Goal 14 is Life Below Water, item 4; and Goal 15 is Life on Land, item 2.

The Bishnoi community of western Rajasthan follows the twenty-nine tenets laid down by Guru Jambheshwar in the fifteenth century, several of which forbid the felling of green trees and the killing of animals, and it is for this reason that khejri groves and herds of blackbuck survive in the desert…

The Forest (Conservation) Act was passed in 1980 to stop the steady loss of forest land to mining, roads, dams and townships.

That is the wording of Sustainable Development Goal 6, the water and sanitation goal. The seventeen Sustainable Development Goals were adopted by the United Nations in September 2015 as part of the 2030 Agenda, and they replaced the eight Millennium Development Goals.

Goal 15, called Life on Land, is the goal for land ecosystems, and its wording covers forests, desertification, land degradation and the loss of biodiversity.

Overgrazing is a cause of soil degradation, not a way to conserve soil, so it is the option that does not belong.

The question asks for the odd one out, and the heavy use of chemical fertilisers damages soil rather than conserving it: it acidifies the soil, kills soil microorganisms, leaves salt residues, and the surplus nitrate and phosphate wash into water bodies and cause eutrophication.

Humus is the dark, formless material left in soil after decomposers have broken down dead leaves, roots and animal remains; it resists further microbial attack and decays only very slowly, which makes it the long term store of carbon and nutrients in soil and a key step in every biogeochemical…