Five short definitions: biosphere, eutrophication, e-waste, decomposers, organic farming

Five of the six terms are defined in about 25-30 words each: (i), (ii), (iii), (v) and (vi).

(i) Biosphere: The thin layer of the Earth in which life can exist, where air, water, rock, soil and all living organisms together form one giant global living system.

(ii) Eutrophication: The over-enrichment of a lake or river with nutrients from sewage or farm fertilisers, which lowers its oxygen sharply, kills fish and other life and produces a foul smell.

(iii) E-waste: Electrical and electronic equipment, whole or in part, discarded as waste, including solar photovoltaic panels and the rejects of manufacturing, refurbishing and repair (E-Waste (Management) Rules, 2022).

(v) Decomposers: Heterotrophic organisms, mainly fungi and bacteria, of the detritus food chain, which begins with dead organic matter; they get energy and nutrients by degrading this detritus into simple inorganic materials.

(vi) Organic farming: Farming without synthetic fertilisers and pesticides, which keeps soil fertile with organic matter and crop rotation; critics doubt its yields, while supporters cite the erosion and pollution it avoids.