TNPSC Biology Environment and Ecology Free Online Test 6

This TNPSC Biology – Environment and Ecology Test 6 covers important topics such as Natural Resources, Climate Change and Sustainable Environment, helping you revise key areas for the TNPSC exam. Attempt this free online test to practise TNPSC Biology questions and strengthen your understanding of environmental topics.

Note: After completing the test, review the detailed explanations below to reinforce your knowledge and identify areas that need more attention.

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Environment And Ecology Test 6 – Detailed Answers with Examples

This detailed explanation section provides a clear understanding of the important TNPSC Biology – Environment and Ecology topics covered in this free online Test 6, including Natural Resources, Climate Change and Sustainable Environment. Go through each explanation to understand the key ideas, environmental importance, conservation practices and sustainable approaches, making it easier to revise and remember these topics for the TNPSC exam.

1. Which of the following is a natural resource?

Answer: B. Coal

Detailed Explanation

A natural resource is a material or substance obtained from nature that is useful to humans.
Coal occurs naturally within the Earth’s crust and is extracted for use as a source of energy.
Coal is a fossil fuel formed from the remains of ancient plants subjected to heat and pressure over millions of years.
It is classified as a non-renewable resource because it takes an extremely long time to form and cannot be replenished on a human timescale.
Natural resources can be broadly classified into renewable and non-renewable resources.

Real-Life Example : Coal is used as a fuel in thermal power plants to generate electricity. The heat released from coal is used to produce steam, which drives turbines connected to generators.

2. Which of the following is a renewable resource?

Answer: C. Solar energy

Detailed Explanation

A renewable resource is a natural resource that is naturally replenished over time.
Solar energy is obtained from sunlight, which is continuously supplied by the Sun.
It can be used repeatedly without being depleted on a human timescale.
Solar energy is considered a clean and renewable source of energy.
Other examples of renewable resources include wind energy, hydropower and biomass.

Real-Life Example: Solar panels installed on rooftops convert sunlight into electricity. Homes, schools and other buildings can use this electricity for lighting, appliances and other daily needs.

3. Which of the following is a non-renewable resource?

Answer: C. Coal

Detailed Explanation

A non-renewable resource is a natural resource available in limited quantities that takes a very long time to form.
Coal is a fossil fuel formed from the remains of ancient plants over millions of years.
Its formation requires specific geological conditions involving heat and pressure.
Coal cannot be replenished quickly enough to meet human consumption.
Therefore, coal is classified as a non-renewable natural resource.

Real-Life Example: Coal is widely used in thermal power plants to produce electricity. Burning coal produces heat, which is used to generate steam and drive turbines connected to generators.

4. Which forest resource is commonly used as a source of fuel?

Answer: B. Fuelwood

Detailed Explanation

Fuelwood is wood obtained from trees or woody vegetation and used as a source of energy.
It is one of the traditional forest resources used for cooking and heating.
Fuelwood can come from naturally fallen wood, branches or sustainably managed sources.
Excessive removal of wood from forests can contribute to deforestation and degradation of forest ecosystems.
Sustainable collection and the use of alternative energy sources can help reduce pressure on forests.

Real-Life Example : In some rural households, firewood is used for cooking in traditional or improved biomass stoves. Using sustainably collected fuelwood can help reduce unnecessary pressure on forest resources.

5. Which of the following is an example of a surface water resource?

Answer: C. River

Detailed Explanation

Surface water refers to water present on the Earth’s surface.
Common examples include rivers, lakes, ponds, streams and reservoirs.
A river is a flowing body of surface water that can be used for agriculture, domestic purposes and other human activities after suitable treatment where necessary.
Surface water is an important part of the water cycle and is replenished mainly through precipitation and runoff.
Groundwater, aquifers and the water table are associated with water found beneath the Earth’s surface.

Real-Life Example : The Cauvery River is an important surface water resource in southern India. Its water supports agriculture, domestic needs and other activities in the regions through which the river and its basin extend.

6. Which practice helps prevent soil erosion?

Answer: C. Afforestation

Detailed Explanation

Soil erosion is the removal of the top layer of soil by agents such as water and wind.
Afforestation involves establishing trees or forests in areas that were previously not forested.
Tree roots help bind and stabilize soil particles, reducing their removal by water and wind.
Vegetation also reduces the impact of rainfall on exposed soil and can slow down surface runoff.
Afforestation therefore plays an important role in soil conservation and environmental protection.

Real-Life Example : Planting trees on degraded or barren land can help stabilize the soil and reduce soil loss during heavy rainfall. Vegetation cover is particularly useful on slopes, where uncontrolled runoff can wash away valuable topsoil.

7. Which approach promotes the long-term conservation of natural resources?

Answer: A. Sustainable use

Detailed Explanation

Sustainable use means using natural resources carefully while ensuring that they remain available for future needs.
It involves avoiding unnecessary consumption, wastage and overexploitation of resources.
Sustainable resource management considers both present requirements and the long-term health of the environment.
It can be applied to resources such as forests, water, soil, minerals and energy.
Sustainable use is an important principle of environmental conservation and sustainable development.

Real-Life Example : In forestry, selective harvesting and replanting trees can provide timber while maintaining forest cover and allowing the forest ecosystem to regenerate. This is more sustainable than clearing large areas of forest without allowing regeneration.

8. The main purpose of rainwater harvesting is to

Answer: B. Collect and store rainwater

Detailed Explanation

Rainwater harvesting is the collection and management of rainwater for later use or for groundwater recharge.
Rainwater can be collected from rooftops, paved areas and other suitable surfaces.
The collected water may be stored in tanks or directed into suitable structures for groundwater recharge.
It can help reduce dependence on other water sources, particularly during periods of water scarcity.
Properly designed rainwater harvesting systems can also help manage excess surface runoff.

Real-Life Example : In a rooftop rainwater harvesting system, rain falling on a building’s roof is directed through pipes into a storage tank. The collected water can be used for suitable household purposes, while some systems direct water into recharge structures to replenish groundwater.

9. Which practice directly helps in groundwater conservation?

Answer: B. Rainwater recharge

Detailed Explanation

Groundwater is water stored below the Earth’s surface in soil and rock formations.
Rainwater recharge allows water to infiltrate into the ground and replenish underground water reserves.
Recharge can occur naturally through infiltration, but human-made recharge structures can also increase the amount of rainwater entering the ground.
Excessive groundwater extraction can lower the groundwater level when withdrawal exceeds natural or managed recharge.
Therefore, promoting groundwater recharge is an important part of groundwater conservation.

Real-Life Example : A recharge pit can collect rainwater and allow it to slowly infiltrate into the surrounding soil. In suitable locations, this helps replenish underground water reserves and can support groundwater availability.

10. Sustainable development aims to

Answer: B. Meet present needs without compromising future generations

Detailed Explanation

Sustainable development aims to improve human well-being while protecting natural resources and the environment for the future.
It considers the interconnected needs of economic development, social well-being and environmental protection.
The approach encourages efficient use of resources and reduction of environmental damage.
It seeks to meet the needs of the present without reducing the ability of future generations to meet their own needs.
Sustainable development is therefore closely connected with resource conservation and environmental sustainability.

Real-Life Example : Using solar and wind energy instead of relying entirely on fossil fuels can help meet present energy needs while reducing dependence on finite resources and lowering environmental impacts.

11. Global warming refers to the

Answer: B. Long-term rise in Earth’s average temperature

Detailed Explanation

Global warming refers to the long-term increase in the average temperature of Earth’s surface and lower atmosphere.
The primary cause of recent global warming is the increased concentration of heat-trapping greenhouse gases due largely to human activities.
Major sources include the burning of fossil fuels, deforestation and certain industrial and agricultural activities.
Global warming is one important component of broader climate change, which includes changes in temperature, rainfall patterns and other climate characteristics.
It is measured over long periods rather than from short-term daily or seasonal temperature changes.

Real-Life Example : The long-term warming of the planet can contribute to the melting of glaciers and ice sheets and rising sea levels. These changes can affect coastal regions, ecosystems and communities that depend on stable climate conditions.

12. Which phenomenon causes warming of Earth’s lower atmosphere by trapping heat?

Answer: A. Greenhouse effect

Detailed Explanation

The greenhouse effect is the natural process by which certain gases in Earth’s atmosphere absorb and re-emit part of the outgoing infrared radiation.
This process helps keep Earth’s surface and lower atmosphere warm enough to support life.
Important greenhouse gases include water vapour, carbon dioxide, methane and nitrous oxide.
Human activities have increased the concentrations of several greenhouse gases, strengthening the natural greenhouse effect and contributing to global warming.
The greenhouse effect should therefore not be confused with the ozone layer, which has a different role in the atmosphere.

Real-Life Example : When sunlight reaches Earth’s surface, the surface absorbs some of that energy and later releases heat as infrared radiation. Greenhouse gases in the atmosphere absorb and re-emit part of this outgoing heat, helping keep the lower atmosphere warmer.

13. Which of the following is a greenhouse gas?

Answer: C. Carbon dioxide

Detailed Explanation

Carbon dioxide (CO₂) is an important greenhouse gas present naturally in the atmosphere.
It absorbs part of the infrared radiation emitted by Earth’s surface and contributes to the greenhouse effect.
Human activities such as burning coal, petroleum and natural gas increase the concentration of carbon dioxide in the atmosphere.
Other important greenhouse gases include methane, nitrous oxide and water vapour.
Oxygen, nitrogen and argon are major atmospheric gases but are not significant greenhouse gases.

Real-Life Example : When petrol or diesel is burned in vehicles, carbon-containing fuels react with oxygen and release carbon dioxide. The increased atmospheric concentration of CO₂ contributes to the enhanced greenhouse effect.

14. Climate change refers to

Answer: B. Long-term changes in climate patterns

Detailed Explanation

Climate change refers to long-term changes in Earth’s climate characteristics and patterns.
These changes can involve temperature, rainfall, wind patterns and the frequency or intensity of some extreme weather events.
Climate is different from weather: weather describes short-term atmospheric conditions, while climate describes patterns over much longer periods.
Modern climate change is influenced strongly by human activities that increase greenhouse gas concentrations.
Climate change can affect ecosystems, agriculture, water resources and human communities.

Real-Life Example : Changes in long-term rainfall patterns can affect agriculture and water availability. Farmers may experience changes in the timing or amount of rainfall, requiring adjustments in crop selection and water management.

15. Which substances are mainly responsible for stratospheric ozone depletion?

Answer: A. Chlorofluorocarbons

Detailed Explanation

Chlorofluorocarbons (CFCs) are human-made chemicals that were widely used in refrigeration, air-conditioning systems, aerosol products and foam production.
CFCs can reach the stratosphere, where ultraviolet radiation breaks them down and releases chlorine atoms.
These chlorine atoms participate in chemical reactions that destroy ozone (O₃) molecules.
The reduction of stratospheric ozone allows more harmful ultraviolet-B (UV-B) radiation to reach Earth’s surface.
The international Montreal Protocol has played an important role in controlling the production and consumption of ozone-depleting substances.

Real-Life Example : Older refrigerators and air-conditioning equipment used certain CFCs as refrigerants. Modern refrigeration systems increasingly use alternatives with much lower ozone-depletion potential, helping reduce damage to the stratospheric ozone layer.

16. Acid rain can cause

Answer: B. Damage to aquatic ecosystems and buildings

Detailed Explanation

Acid rain refers to precipitation that is more acidic than normal because atmospheric pollutants form acids when they react with water and other substances.
Sulfur dioxide (SO₂) and nitrogen oxides (NOₓ) are major pollutants involved in the formation of acid deposition.
Acidic water can lower the pH of lakes and streams, creating harmful conditions for fish and other aquatic organisms.
Acid deposition can also react with and gradually damage certain building materials, monuments and metals.
The effects of acid rain vary depending on the sensitivity of the soil, water bodies and materials exposed to it.

Real-Life Example: Acid deposition can contribute to the deterioration of limestone and marble structures. Acidic pollutants can react with the minerals in these materials, gradually weakening and damaging exposed surfaces.

17. Which of the following is a renewable source of clean energy?

Answer: C. Wind energy

Detailed Explanation

Wind energy uses the natural movement of air to produce useful energy.
Wind turbines convert the kinetic energy of moving air into electrical energy.
Wind is naturally replenished through atmospheric processes, so it is considered a renewable energy source.
Electricity generation from wind does not require burning fossil fuels during operation, resulting in very low direct greenhouse gas emissions.
Wind energy is therefore an important part of the transition towards cleaner and more sustainable energy systems.

Real-Life Example: Large wind farms use groups of wind turbines to generate electricity. In India, wind farms are especially important in states such as Tamil Nadu and Gujarat, where suitable wind conditions support electricity generation.

18. Which action best supports environmental protection?

Answer: B. Conserving water and energy

Detailed Explanation

Environmental protection involves actions that reduce pressure on natural resources and minimize damage to ecosystems.
Conserving water and energy helps reduce unnecessary consumption of valuable resources.
Efficient energy use can also reduce the amount of fossil fuels required for electricity and other energy needs.
Water conservation helps maintain the availability of freshwater for people, agriculture and ecosystems.
Simple conservation practices, when adopted widely, can contribute to a more sustainable environment.

Real-Life Example : Turning off lights and fans when they are not needed and fixing leaking taps are simple ways to conserve energy and water at home. These small actions can reduce resource wastage in everyday life.

19. Which of the following is an example of a sustainable lifestyle practice?

Answer: B. Using public transport when suitable

Detailed Explanation

A sustainable lifestyle involves making choices that reduce environmental impact while meeting everyday needs.
Using public transport can reduce the number of individual vehicles on roads.
When public transport is well utilized, it can reduce fuel consumption and emissions per passenger compared with many individual car journeys.
Other sustainable practices include reducing unnecessary consumption, conserving water and energy, and avoiding waste.
Sustainable living encourages the responsible use of resources for both present and future needs.

Real-Life Example : A person travelling to school or work can choose a bus or train instead of travelling alone in a car, when convenient and available. This can reduce the number of vehicles on the road and help lower fuel use and transport-related emissions.

20. Which of the following is a major global environmental issue?

Answer: A. Climate change

Detailed Explanation

Climate change is a major global environmental issue involving long-term changes in Earth’s climate patterns.
Rising concentrations of greenhouse gases are a major driver of current human-caused climate change.
Climate change can affect temperature patterns, rainfall, sea levels, ecosystems, agriculture and water resources.
Because Earth’s climate system is interconnected, its effects can extend across countries and regions.
Addressing climate change requires measures such as reducing greenhouse gas emissions, improving energy efficiency, protecting ecosystems and adapting to unavoidable impacts.

Real-Life Example : Changes in temperature and rainfall patterns can affect agriculture and water availability. Farmers may need to adjust crop choices, planting times or water-management practices as local climate conditions change.

Further Reference – To Learn More About Environment and Ecology

For a deeper understanding of Environment and Ecology, including natural resources, climate change, environmental conservation and sustainable development, read NCERT Our Environment lesson. It provides additional explanations and key information that can help you strengthen your TNPSC Biology preparation and revise these topics with greater clarity.