Green Skills

Correct answer: C. Using resources wisely according to need

The correct answer is C: using resources wisely according to need. Sustainable consumption means meeting present needs without wasting resources or making it difficult for future generations to meet their needs. A responsible consumer considers how much is needed, chooses durable or repairable products, avoids unnecessary packaging, reuses items and disposes of waste properly. Saving water and energy are also parts of responsible consumption. A is wrong because buying excessive quantities can waste materials. B is the opposite of careful use. D deliberately increases waste and pollution. Sustainable consumption does not mean that nobody may buy or use anything; it means using products and natural resources thoughtfully, efficiently and responsibly. Memory cue: need, use carefully, reuse and waste less.

Correct answer: D. It causes less harm to nature

The correct answer is D: it causes less harm to nature. An eco-friendly product is designed, produced, used and discarded in a way that generally places a lower burden on the environment than comparable products. Useful features may include lower energy or water use, safer materials, durability, repairability, reduced packaging and the possibility of recycling. D is correct because it states the central idea without claiming that the product has absolutely zero impact. A is wrong because producing more waste is harmful. B is wrong because toxicity is not an eco-friendly feature. C is usually wasteful because a single-use product may need frequent replacement. Consumers should consider the product’s whole life cycle, not only a label or advertisement. Memory cue: eco-friendly means less environmental harm, not necessarily no impact.

Correct answer: A. Recycling and safe disposal become easier

Waste segregation means keeping different kinds of waste, such as wet biodegradable waste, dry recyclable material and hazardous or electronic waste, in separate streams. This makes collection, sorting, composting, recycling and safe treatment more efficient and reduces contamination. Therefore, option A is correct. Wet organic waste can be processed into compost, while clean paper, glass, metal and some plastics may be recovered for recycling. Mixing everything can spoil recyclable material and expose workers or the environment to hazards. Segregation does not make waste toxic or send it to rivers.

Correct answer: B. It can be replenished through natural processes

The governing concept is renewability: a renewable resource can be restored or replenished by natural processes at a rate that may support continued use when it is managed responsibly. Sunlight, wind and flowing water are common examples. Therefore, option B is correct because it directly describes the defining feature of this resource group. Option A describes rapid exhaustion, which is not the general meaning of renewable. Option C incorrectly limits resources to underground metals; many renewable resources are natural energy flows. Option D is also false because people regularly use renewable resources. Sustainable use still matters, because even renewable resources can be damaged or depleted if consumption is careless.

Correct answer: C. Fuel consumption and air pollution decrease

The governing concept is clean or green transport. A bicycle is powered by the rider rather than by petrol or diesel combustion, so using it for suitable journeys can reduce fuel consumption, exhaust emissions and traffic-related air pollution. Option C is correct because it states both major environmental benefits. Option A is the opposite: cycling normally produces no tailpipe smoke. Option B is also opposite because a bicycle does not require petrol for movement. Option D is not the normal direct result of cycling; choosing a bicycle generally avoids some vehicle use rather than creating more solid waste. The size of the benefit depends on how many motorised trips are replaced, but the environmental direction remains positive.

Correct answer: D. Writing on both sides

The governing concept is resource conservation, especially the Reduce principle in the 3R approach: Reduce, Reuse and Recycle. Writing on both sides of a sheet allows more information to be recorded with fewer sheets. As a result, paper consumption is reduced, and fewer raw materials, water and energy may be needed for paper production. Option D is therefore correct. Option A wastes usable paper, while option B deliberately leaves part of each sheet unused. Option C destroys books, creates smoke and does not conserve paper. In practice, paper should be used carefully, blank portions can sometimes be reused for rough work, and unwanted paper should be recycled after use.

Correct answer: A. Paper

The governing concept is dematerialisation: replacing a physical paper copy with a digital record can reduce the need for printing and repeated photocopying. Digital notes can be created, stored, searched and shared on a suitable device, so the most direct resource saved in this question is paper. Option A is correct. Digital devices still use electricity and their manufacture has environmental impacts, so digital notes are not completely impact-free; however, those facts do not change the direct answer. Coal, cement and petrol are not the resource specifically replaced by writing or storing ordinary study notes digitally. Responsible users should also manage electronic waste and energy use properly.

Correct answer: B. Reusing bottles and reducing plastic bottle consumption

The governing concept is the 3R approach, particularly Reduce and Reuse. A refill bottle is designed to be filled and used many times, so a person does not need to purchase a new single-use plastic bottle for every drink. This can reduce the amount of plastic entering the waste stream and conserve materials used in manufacturing and transport. Option B is correct because it names both the repeated-use habit and the reduction in disposable bottle consumption. Option A describes the opposite behaviour. Options C and D concern water wastage and waste segregation; they are not the direct habit promoted by using a refill bottle. The bottle should still be cleaned and maintained safely.

Correct answer: C. Long-distance transport and related fuel use may reduce

The governing concept is sustainable consumption and reduction of transport impact. Food obtained near its place of production may travel a shorter distance before reaching consumers. When long-distance transport is avoided or reduced, vehicles may use less fuel and produce fewer transport-related emissions. Therefore, option C expresses the possible environmental benefit. The word “may” is important: local food does not automatically have a lower impact in every situation, because farming methods, storage, season and packaging also matter. Option B states the reverse. Options A and D use absolute claims that do not necessarily follow from choosing local food. Consumers should also avoid waste and prefer appropriate, minimally packaged food when practical.

Correct answer: D. Taking care of it

The governing concept is sustained environmental stewardship: planting is only the beginning, and a young tree needs continuing care to survive and grow. Appropriate watering, protection from grazing animals or damage, support when needed, weed control and attention to soil conditions can help it establish roots. Option D is correct because care converts a planting activity into a lasting environmental benefit. Option A destroys the tree, while option B can damage roots and reduce access to suitable soil. Option C removes an essential condition for growth, except where natural rainfall is genuinely sufficient. Care should be suited to the species, season and local conditions rather than applying the same watering schedule everywhere.

Correct answer: B. Using LED bulbs to save energy

The governing concept of sustainable development is meeting present needs while conserving resources and reducing harm for future generations. LED bulbs generally provide required lighting with less electricity than many older lighting technologies. Using them can reduce energy demand and, depending on the electricity source, associated emissions. Option B is therefore the sustainable action. More single-use plastic increases material consumption and waste. Dumping unsorted waste in open areas can pollute soil, water and air, while unplanned construction in forests can damage habitats and biodiversity. Energy-efficient lighting is only one part of sustainability; it should be combined with switching lights off when unnecessary, responsible purchasing and proper waste management.

Correct answer: B. Responsible environmental behaviour

The governing concept is responsible environmental behaviour. Keeping a campus clean involves using bins correctly, avoiding litter, segregating waste where facilities exist, and helping maintain shared spaces. These actions protect health, improve the surroundings and show that students and staff accept collective responsibility for the environment. Option B is correct because a clean campus reflects responsible care rather than a single accidental act. Option A describes littering, which creates an unhygienic environment. Option C concerns unnecessary water use and is not implied by cleanliness. Option D is a separate form of pollution involving excessive or disturbing sound. A clean campus should also be maintained through regular action, not merely prepared for inspection or a special event.

Correct answer: C. Understanding environmental problems, their causes and solutions

The governing concept is environmental awareness: having informed understanding of environmental conditions, problems, causes, consequences and possible solutions, followed by responsible choices. It includes recognising issues such as pollution, waste, resource depletion and habitat loss, and understanding how personal and community actions affect them. Option C is correct because it includes both knowledge of problems and consideration of their causes and solutions. Option A hides information instead of building understanding. Option B increases pressure on natural resources, and option D causes pollution and public-health risks. Awareness is more than memorising terms; it should guide practical behaviour such as conserving water and energy, reducing waste, segregating materials and protecting living systems.

Correct answer: D. Putting waste in a dustbin

The direct answer is D: putting waste in a dustbin. A green habit is a small daily action that protects nature and uses resources responsibly. When waste is placed in a dustbin, it can be collected and, where facilities exist, separated into recyclable, biodegradable, and other waste. This helps keep roads and public places clean and reduces the chance that rubbish will enter drains, soil, rivers, or other water bodies. It also makes later recycling, composting, or safe treatment easier. Option A is wrong because throwing waste on the road causes litter and can spread pollution. Option B is wrong because an open tap wastes clean water. Option C is wrong because an unnecessary fan uses electricity. Option D is correct because it is simple, responsible, and supports proper waste management. Memory cue: use the bin, save the environment.

Correct answer: A. Diesel

The direct answer is A: diesel. Non-renewable resources are available in limited amounts and cannot be replaced quickly enough for the rate at which people use them. Diesel is made from petroleum, and petroleum is a fossil fuel formed by natural geological processes over a very long period. Once used, a petroleum reserve cannot be restored within a human lifetime. Option B is incorrect because sunlight is continuously supplied by the Sun and is treated as a renewable energy source. Option C is incorrect because wind is naturally produced by movements and differences in heating within the atmosphere, so it is replenished. Option D is not normally classified as an energy source at all; rainwater is part of the water cycle. The important distinction is not whether something is useful, but whether nature replaces it quickly. Memory cue: fossil fuels are finite; sunlight and wind are replenished.

Correct answer: B. Becoming responsible and environmentally aware

The governing concept is that green skills combine environmental awareness with practical, responsible action. A student who learns these skills can understand resource conservation, reduce waste, save water and energy, prefer sustainable practices, and participate in protecting the local environment. Such learning also develops useful workplace and life habits rather than remaining only theoretical knowledge. Increasing waste, deliberately wasting water, or damaging devices contradicts the purpose of green skills. Therefore, option B correctly describes the benefit: becoming responsible and environmentally aware.

Correct answer: A. An economy that causes less environmental harm

The direct answer is A: an economy that causes less environmental harm. A green economy supports people’s well-being, livelihoods, and useful economic activity while trying to reduce pollution, waste, environmental damage, and wasteful use of natural resources. It encourages cleaner production, efficient use of materials and energy, conservation of nature, renewable energy, and responsible employment. It does not mean that all factories, trade, or development must stop. Rather, it means planning development so that present needs are met without unnecessarily damaging the environment and reducing future choices. Option B is wrong because increasing waste conflicts with resource efficiency. Option C is wrong because wasting water is not sustainable. Option D is wrong because careless tree cutting harms ecosystems. Memory cue: green economy means development with environmental responsibility.

Correct answer: B. An environment-friendly business

The governing concept is green entrepreneurship, which combines business initiative with environmental responsibility. A green entrepreneur develops or provides products and services that meet customer needs while reducing pollution, conserving resources, lowering waste, or supporting cleaner energy. Examples may include recycling services, energy-efficient products, organic farming, or renewable-energy solutions. The aim is not merely to earn profit by any method; environmental impact is considered along with economic value. Options A, C, and D describe unsustainable conduct, so option B is correct.

Correct answer: C. Greenhouse gas

The direct answer is C: greenhouse gas. Carbon dioxide, written as CO₂, is a greenhouse gas because it can absorb and re-emit part of the infrared heat that Earth’s surface gives off. This property is part of the natural greenhouse effect, which helps keep Earth warm enough for life. However, human activities such as burning coal, oil, and gas can increase the amount of carbon dioxide in the atmosphere. A larger concentration can strengthen warming and contribute to climate change. Option A is wrong because oxygen is a different gas and supports respiration and combustion. Option B is wrong because carbon dioxide is not classified as an inert gas. Option D is wrong because ozone is a different molecule, O₃, although ozone can also take part in atmospheric processes. Memory cue: CO₂ holds heat, so remember it as a greenhouse gas.

Correct answer: D. Trapping of heat in the atmosphere

The governing concept is atmospheric heat retention. The greenhouse effect occurs when certain gases, including carbon dioxide, methane, and water vapour, absorb and re-emit outgoing infrared radiation, so some heat remains in the atmosphere instead of escaping directly into space. The natural effect helps maintain a temperature suitable for life; an enhanced effect can cause additional warming. Drying a river, counting trees, and recycling paper may relate to environmental topics, but none defines this process. Therefore, option D is correct.

Correct answer: A. Absorbing harmful ultraviolet radiation from the Sun

The direct answer is A: absorbing harmful ultraviolet radiation from the Sun. The ozone-rich region in the stratosphere absorbs much of the ultraviolet radiation that could harm living organisms. In particular, it absorbs nearly all UV-C and a substantial part of UV-B. This protection helps reduce damage to human skin and eyes and also protects plants, animals, and microorganisms. Option B is wrong because most atmospheric oxygen is produced through photosynthesis by plants, algae, and some microorganisms, not by the ozone layer. Option C is wrong because temperature is influenced by many factors and direct temperature control is not the ozone layer’s main function. Option D is wrong because water vapour comes mainly from evaporation and other parts of the water cycle. Do not confuse the ozone layer with the broader greenhouse effect. Memory cue: ozone shields Earth from harmful UV rays.

Correct answer: B. Solar energy

The direct answer is B: solar energy. A solar cooker collects radiant energy from sunlight and changes it into heat. Reflective surfaces can direct sunlight toward the cooking area, while a dark vessel and insulation can help absorb and retain heat. Because its main source is the Sun, the cooker can prepare food without directly burning diesel, coal, or biogas. Option A is wrong because diesel is a petroleum-based fuel. Option C is wrong because coal is a fossil fuel burned in other kinds of stoves or power systems. Option D is wrong because biogas is produced from organic matter and is used as a combustible gas, but it is not the source used by a solar cooker. The word “solar” is the key clue. Memory cue: solar cooker means sunlight converted into cooking heat.

Correct answer: C. Organic waste

The governing concept is anaerobic decomposition of biodegradable organic matter. Biogas is commonly produced in a digester when microorganisms break down materials such as animal dung, food scraps, sewage, and other plant or kitchen waste in the absence of oxygen. The gas usually contains methane, which can be burned as a fuel, and carbon dioxide. This process also supports waste management by converting some waste into useful energy and digestate. Plastic toys, glass bottles, and iron rods are not suitable biodegradable feedstock, so option C is correct.

Correct answer: D. Earthworms

The governing concept is vermicomposting, a biological method of converting biodegradable organic waste into useful compost. The word “vermi” refers to worms, especially earthworms, which feed on and help decompose materials such as vegetable peels, dry leaves, and other suitable organic matter. Their activity produces a dark, nutrient-rich compost that can improve soil structure and fertility. Therefore, option D, earthworms, is correct. Mosquitoes are not composting organisms, a wall cannot decompose waste, and plastic is non-biodegradable and does not become compost. Safe vermicomposting also requires suitable moisture, air, and organic feed.

Correct answer: A. Saving water

Drip irrigation is a method in which water is delivered slowly and in a controlled way near the roots of individual plants. Because the water is placed close to the root zone, less water is lost through surface flow, evaporation or wetting areas where plants do not need it. This makes the method useful for conserving water, especially when water is limited. It can also provide more regular moisture to crops.

Option A is correct because saving water is the main benefit highlighted in this question. Option B states the opposite of the purpose of drip irrigation. Option C is harmful and unrelated to the method, while option D would destroy crops rather than support their growth. The technique does not mean that no water is ever lost, but it generally uses water more efficiently than broad flooding. Thus it is an important water-conservation practice.