Everyday Science - PMS 2026 GK (Q401-450): Ecology, Environment & Sustainability MCQs

Correct Answer: Interaction of living & non-living components

An ecosystem is defined as the interaction of living (biotic) and non-living (abiotic) components in an area.

Correct Answer: Variety of life forms

Biodiversity refers to the variety of life forms (genes, species and ecosystems) in an area.

Correct Answer: Variation within species

Genetic diversity is variation within a species, i.e. differences in genes between individuals of the same species.

Correct Answer: Number of species in an ecosystem

Species diversity is the number (and variety) of species present in an ecosystem.

Correct Answer: Variety of ecosystems in a region

Ecosystem diversity is the variety of ecosystems (habitats, communities and landscapes) in a region.

Correct Answer: Plants / photosynthetic organisms

Producer organisms are plants and other photosynthetic organisms, which make their own food from sunlight.

Correct Answer: Organisms that eat producers or other consumers

Consumers are organisms that eat producers or other consumers, since they cannot make their own food.

Correct Answer: Flow of energy in ecosystem

A food chain shows the flow of energy in an ecosystem, from producers through successive consumer levels.

Correct Answer: Interconnected food chains

A food web is a network of interconnected food chains in an ecosystem.

Correct Answer: Position in food chain

A trophic level indicates an organism's position in a food chain (producer, primary consumer, and so on).

Correct Answer: Plants, animals, microbes

Biotic components include the living parts of an ecosystem: plants, animals and microbes.

Correct Answer: Sunlight, water, soil, temperature

Abiotic components include the non-living parts of an ecosystem: sunlight, water, soil, temperature and air.

Correct Answer: Hydrological cycle

The water cycle is also called the hydrological cycle.

Correct Answer: Water turning into vapor

Evaporation is water turning into vapor (gas), usually from a liquid surface.

Correct Answer: Water vapor forming clouds

Condensation is water vapor cooling and forming liquid droplets, seen as clouds and dew.

Correct Answer: Rain, snow, sleet, hail

Precipitation includes rain, snow, sleet and hail: water falling from clouds to the ground.

Correct Answer: Infiltration

Groundwater recharge occurs via infiltration: surface water soaking down through the soil into aquifers.

Correct Answer: CO2, CH4, N2O

Greenhouse gases include carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O).

Correct Answer: Increased greenhouse gases

Global warming is caused by increased greenhouse gases trapping more heat in the atmosphere.

Correct Answer: Harmful UV radiation

The ozone layer protects life from harmful ultraviolet (UV) radiation from the Sun.

Correct Answer: Deplete ozone layer

CFCs (chlorofluorocarbons) are harmful because they deplete the ozone layer.

Correct Answer: Sulfur & nitrogen oxides

Acid rain is caused by sulfur dioxide and nitrogen oxides released into the air, which form acids in rain.

Correct Answer: Water, wind & deforestation

Soil erosion is caused by water, wind and deforestation (which removes the plant cover holding soil).

Correct Answer: Deforestation & overgrazing

Desertification occurs due to deforestation and overgrazing, which strip vegetation and degrade dry land.

Correct Answer: Biodiversity & climate

Deforestation affects biodiversity and climate: it destroys habitats and removes trees that store carbon.

Correct Answer: Water purification & biodiversity

Wetlands are important for water purification and biodiversity: they filter water and shelter many species.

Correct Answer: Photosynthesis & respiration

The carbon cycle involves photosynthesis (plants take in CO2) and respiration (organisms release CO2).

Correct Answer: Fixation, nitrification, denitrification

The nitrogen cycle involves fixation (N2 to usable forms), nitrification (ammonia to nitrates) and denitrification (nitrates back to N2).

Correct Answer: Igneous, sedimentary & metamorphic rocks

The rock cycle includes igneous, sedimentary and metamorphic rocks, each transforming into the others.

Correct Answer: Weathering of rocks & organic matter

Soil is formed from the weathering of rocks mixed with organic matter (humus).

Correct Answer: Solar, wind, water, biomass

Renewable natural resources include solar, wind, water and biomass energy sources, which replenish naturally.

Correct Answer: Coal, petroleum, natural gas

Non-renewable resources include coal, petroleum and natural gas: fossil fuels that do not replenish on a human timescale.

Correct Answer: Meeting present needs without harming future

Sustainable development means meeting present needs without harming the ability of future generations to meet theirs.

Correct Answer: Reduce, reuse, recycle

Waste management includes reduce, reuse and recycle: the three Rs for cutting waste.

Correct Answer: Air, water & soil

Industrial pollution mainly affects air, water and soil around factories and industrial sites.

Correct Answer: Industrial, domestic & agricultural

Water pollution sources include industrial effluents, domestic sewage and agricultural runoff.

Correct Answer: Broken down naturally by microbes

Biodegradable waste can be broken down naturally by microbes into harmless substances.

Correct Answer: Persists in environment

Non-biodegradable waste persists in the environment because microbes cannot break it down.

Correct Answer: Climate change & greenhouse gas reduction

The Kyoto Protocol (1997) deals with climate change and greenhouse gas reduction by committed countries.

Correct Answer: Limit global temperature rise

The Paris Agreement (2015) aims to limit global temperature rise to well below 2 degC above pre-industrial levels, pursuing 1.5 degC.

Correct Answer: Endangered species

CITES (the Convention on International Trade in Endangered Species) protects endangered species by regulating their international trade.

Correct Answer: Wetlands conservation

The Ramsar Convention deals with wetlands conservation: wetlands of international importance are listed and protected.

Correct Answer: Climate change negotiations

The UNFCCC (UN Framework Convention on Climate Change) deals with climate change negotiations between countries.

Correct Answer: Reducing greenhouse gas emissions

Carbon credits are related to reducing greenhouse gas emissions: one credit typically represents one tonne of CO2 avoided or removed.

Correct Answer: Conservation & recycling

Sustainable water use involves conservation and recycling of water, so supplies last for future use.

Correct Answer: Solar energy

Energy from sunlight is called solar energy.

Correct Answer: Hydropower

Energy from flowing water is called hydropower (hydroelectric energy).