TNPSC Biology – Environment and Ecology Quiz 1

Environment and Ecology TNPSC Questions – Concept Booster

Understanding the basics of environment and ecology is essential for scoring well in TNPSC exams. These Environment and Ecology TNPSC Questions are designed to help you clearly understand important concepts like ecosystem, biodiversity, food chain, and environmental conservation.

👉 This concept booster includes explanations only for the questions asked in this quiz, helping you learn each concept in a focused and exam-oriented way.

In this section, each question is explained with simple logic and real-life examples so that you can easily remember the concepts. These explanations will not only help you answer similar questions but also strengthen your overall Biology preparation for TNPSC Group 2 and Group 4 exams.

Ecosystem and Its Components

An ecosystem is a system where living organisms like plants, animals, microorganisms are interact with non-living components like air, water, and soil. It includes both biotic (living) and abiotic (non-living) factors working together.

👉 Example: A forest ecosystem includes trees, animals, sunlight, water, and soil.

Remember:

• Producers, consumers, and decomposers are part of an ecosystem
• Energy flows from the sun to plants and then to animals
• Balance in ecosystem is very important for life

Producers, Consumers and Decomposers

Living organisms are classified based on how they get food.

• Producers: Plants make their own food using sunlight (photosynthesis)
• Consumers: Animals depend on plants or other animals
• Decomposers: Bacteria and fungi break down dead organisms

👉 Example: Grass → Deer → Tiger → Fungi

Remember:

• Producers form the base of the food chain
• Decomposers recycle nutrients back to the soil
• Primary consumers eat plants

Photosynthesis and Importance of Carbon Dioxide

Photosynthesis is the process by which plants make food using sunlight, water, and carbon dioxide.

👉 Without carbon dioxide, plants cannot produce food.

Remember:

• Releases oxygen into the atmosphere
• Maintains balance of gases
• Essential for survival of all living beings

Ozone Layer Protection

The ozone layer protects Earth from harmful ultraviolet (UV) rays of the sun.

👉 Damage to ozone layer can cause skin cancer and environmental problems.

Remember:

• Located in the stratosphere
• Absorbs harmful UV radiation
• Needs protection from pollution

Food Chain and Energy Flow

A food chain shows how energy passes from one organism to another in a linear sequence. It usually starts with producers (plants) and moves to herbivores and then to carnivores.

👉 Example: Plants → Herbivores → Carnivores

Energy originates from the sun and is transferred through each level, but only a small portion of energy is passed on while the rest is lost as heat. This is why higher levels in the food chain have fewer organisms.

Remember:

• Energy flows in one direction
• Top level has maximum energy loss
• Only about 10% of energy is transferred to the next level
• Food web is a complex network of food chains

Biodiversity and Its Importance

Biodiversity refers to the variety of plants, animals, and microorganisms in an area. Means the existence of a number of different kinds of animals and plants which together make a good and healthy environment.

In Short, Biological Diversity, is the incredible variety of all living things on Earth—including animals, plants, fungi, and microorganisms—and the ecosystems they form.

👉 High biodiversity means a healthy ecosystem.

Remember:

• Provides ecological balance
• Supports food, medicine, and resources
• Loss of biodiversity leads to imbalance

Deforestation and Its Effects

Deforestation means cutting down forests due to human activities like agriculture and urbanization. Deforestation not only removes trees but also disturbs the natural habitat of many animals, forcing them to migrate or leading to their extinction. This creates imbalance in the ecosystem.

It also reduces rainfall in many regions because trees play a major role in the water cycle. Without forests, the land becomes dry and less fertile over time.

Remember:

• Increases carbon dioxide → leads to global warming
• Causes soil erosion and loss of nutrients
• Affects climate and weather patterns

Global Warming and Greenhouse Gases

Global warming is the increase in Earth’s temperature due to greenhouse gases like carbon dioxide. Greenhouse gases like carbon dioxide, methane, and water vapor trap heat in the Earth’s atmosphere, acting like a blanket and keeping the planet warm. However, excessive increase in these gases due to human activities leads to abnormal temperature rise

This results in serious environmental effects such as rising sea levels, irregular rainfall, and extreme weather conditions like heatwaves and floods, which directly impact both nature and human life.

Remember:

• Burning fossil fuels is the main cause. Fuels like coal, petrol, diesel, and natural gas for energy, they release large amounts of carbon dioxide (CO₂) into the atmosphere.
• Methane is more powerful than carbon dioxide (It means methane traps more heat in the atmosphere per unit compared to carbon dioxide.)
• Increase in CO₂ is the major reason for global warming.

Pollution and Its Types

Pollution is the contamination of air, water, or soil by harmful substances. Pollution not only affects the environment but also directly impacts human health, causing respiratory problems, waterborne diseases, and soil contamination. It disturbs the natural balance and harms plants, animals, and ecosystems.

Human activities like industrial waste, vehicle emissions, plastic usage, and improper disposal of garbage are the major causes of pollution nowadays.

Quick Extra Points:

• Air pollution leads to breathing issues and climate problems
• Water pollution affects drinking water and aquatic life
• Soil pollution reduces land fertility and crop quality
• Noise pollution causes stress and hearing problems

Types:

• Air Pollution: Caused by smoke, dust, and harmful gases 👉 Example: Vehicle emissions and factory smoke
• Water Pollution: Contamination of water bodies like rivers and lakes 👉 Example: Dumping sewage or industrial waste into rivers
• Soil Pollution: Damage to soil due to chemicals and waste 👉 Example: Excess use of pesticides and plastic waste
• Noise Pollution: Unwanted or harmful sound 👉 Example: Loudspeakers, traffic noise, construction work

Renewable and Non-Renewable Resources

Resources are classified based on their availability. Renewable resources are naturally replenished over a short period of time and are considered sustainable for long-term use. They cause less environmental pollution and are important for future energy needs.

Non-renewable resources are limited in quantity and take millions of years to form. Excessive use of these resources leads to depletion and environmental damage, making conservation very important.

• Renewable resources: Can be reused (solar energy, wind)
• Non-renewable resources: Limited (coal, petroleum)

Remember:

• Solar, wind, and water are major renewable energy sources
• Coal, petroleum, and natural gas are non-renewable
• Renewable resources help reduce global warming
• Conservation of non-renewable resources is essential

Conservation of Environment

Conservation means protecting and managing natural resources wisely. The protection and proper management of natural resources like air, water, soil, forests, and wildlife to maintain ecological balance. It ensures that these resources are available for future generations.

It also involves reducing pollution, saving energy, and promoting sustainable practices like recycling and using renewable resources. Human responsibility plays a key role in protecting the environment.

Key Points:

• Includes afforestation and wildlife protection
• Reduces environmental damage and climate change
• Encourages sustainable use of resources
• Protects biodiversity and ecosystem balance

Water Cycle

The water cycle includes processes like evaporation, condensation, and rainfall. The water cycle is a continuous natural process in which water circulates between the Earth’s surface and the atmosphere. It includes key stages like evaporation, condensation, and precipitation.

Sunlight heats water from oceans, rivers, and lakes causing evaporation. The water vapor then cools and forms clouds (condensation), which later fall as rain (precipitation), completing the cycle.

Remember:

• Maintains water balance on Earth
• Essential for plants, animals, and humans
• Supports agriculture and climate system
• Includes processes like evaporation, condensation, and rainfall

Acid Rain

Acid rain is caused by pollutants like sulfur dioxide and nitrogen oxides. Acid rain is a type of precipitation that contains harmful acids formed when pollutants like sulfur dioxide (SO₂) and nitrogen oxides (NOₓ) mix with water vapor in the atmosphere.

These pollutants mainly come from burning fossil fuels in vehicles, factories, and power plants. When acid rain falls on Earth, it damages plants, soil, water bodies, and even buildings.

Key Points:

• Damages plants and buildings
• Pollutes water bodies
• Harmful to environment
• Harms crops and forests
• Makes soil less fertile
• Affects aquatic life in rivers and lakes

Afforestation and Environmental Balance

Afforestation means planting new trees to restore forests. Afforestation means planting trees in areas where there were no forests or where forests have been destroyed. It helps restore ecological balance and improves environmental quality.

Trees play a major role in maintaining balance by absorbing carbon dioxide, releasing oxygen, conserving water, and supporting wildlife. Increasing forest cover helps reduce the effects of global warming and climate change.

Key Points:

• Prevents soil erosion and improves soil fertility
• Helps in maintaining the water cycle and rainfall
• Provides habitat for animals and birds
• Reduces pollution and improves air quality

Final Revision Tips :

✔ Ecosystem = interaction of living (biotic) and non-living (abiotic) components

✔ Producers → Consumers → Decomposers (basic structure of food chain)

✔ Energy flow is one-way and only 10% energy is transferred to the next level

✔ Carbon dioxide is essential for photosynthesis

✔ Ozone layer protects Earth from harmful UV rays

✔ Biodiversity ensures ecosystem stability and balance

✔ Deforestation leads to climate change, soil erosion, and loss of wildlife

✔ Global warming is mainly caused by greenhouse gases like CO₂ and methane

✔ Pollution types: Air, Water, Soil, Noise (with real-life examples)

✔ Renewable resources (solar, wind) vs Non-renewable (coal, petroleum)

✔ Conservation of environment is necessary for future generations

✔ Water cycle = evaporation → condensation → precipitation

✔ Acid rain is caused by SO₂ and NOₓ and damages environment

✔ Afforestation helps maintain ecological balance and reduces global warming

📚 Authority Reference

Reference: NCERT Class 12 Biology – Ecology Unit