TNPSC Biology Environment and Ecology Quiz 1

TNPSC Biology Environment and Ecology Quiz 1 – 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.

Q1. What is an ecosystem?

An ecosystem is a functional unit of nature where living organisms such as plants, animals, and microorganisms interact with one another and with non-living components like air, water, soil, and sunlight. These interactions help maintain ecological balance.

Key Points:

• Includes biotic and abiotic components
• Energy flows through food chains
• Nutrient cycling occurs continuously
• Can be terrestrial or aquatic

Real-Life Example:
A pond ecosystem contains fish, aquatic plants, insects, microorganisms, water, and sunlight working together.

Answer: Interaction of living and non-living things

Q2. Which of the following is a producer?

Producers are organisms that manufacture their own food using sunlight through the process of photosynthesis. They form the first trophic level in a food chain.

Key Points:

• Also called autotrophs
• Convert solar energy into chemical energy
• Support all other organisms in the ecosystem
• Essential for oxygen production

Real-Life Example:
Grass in a field produces food using sunlight and serves as food for herbivores such as goats and cows.

Answer: Grass

Q3. Which organism is a primary consumer?

Primary consumers are organisms that feed directly on producers (plants). They occupy the second trophic level in a food chain and are commonly known as herbivores. By consuming plants, they transfer energy from producers to higher-level consumers.

Key Points:

• Feed directly on plants
• Also called herbivores
• Occupy the second trophic level
• Serve as food for secondary consumers

Real-Life Example:
A goat eats grass in a field. Here, grass is the producer and the goat is the primary consumer.

Answer: Goat

Q4. Which gas is most important for photosynthesis?

Photosynthesis is the process by which green plants prepare their food using sunlight, water, and carbon dioxide. During this process, plants absorb carbon dioxide from the atmosphere and release oxygen.

Key Points:

• Essential raw material for photosynthesis
• Absorbed through leaf stomata
• Used to produce glucose
• Helps maintain the carbon cycle

Real-Life Example:
Trees in parks absorb carbon dioxide from the air and produce oxygen, making the environment healthier.

Answer: Carbon dioxide

Q5. Which layer protects Earth from harmful UV rays?

The ozone layer is a region in the stratosphere containing a high concentration of ozone gas (O₃). It acts as a protective shield by absorbing most of the Sun’s harmful ultraviolet (UV) radiation.

Key Points:

• Located in the stratosphere
• Contains ozone gas (O₃)
• Absorbs harmful UV rays
• Protects living organisms from skin and eye damage

Real-Life Example:
Without the ozone layer, excessive UV radiation could increase the risk of skin cancer and harm crops.

Answer: Ozone Layer

Q6. What is a food chain?

A food chain is a sequence of organisms through which energy and nutrients pass as one organism eats another. It begins with producers and moves through different levels of consumers.

Key Points:

• Shows the flow of energy in an ecosystem
• Starts with producers
• Includes consumers at different levels
• Ends with decomposers

Real-Life Example:
Grass → Goat → Tiger is a simple food chain.

Answer: Transfer of energy through organisms

Q7. Which of the following is a decomposer?

Decomposers are organisms that break down dead plants, animals, and organic waste into simpler substances. This process returns nutrients to the soil and supports plant growth.

Key Points:

• Break down dead organisms
• Recycle nutrients in nature
• Maintain soil fertility
• Mainly include fungi and bacteria

Real-Life Example:
Mushrooms growing on dead wood help decompose it and release nutrients back into the environment.

Answer: Fungi

Q8. What is biodiversity?

Biodiversity refers to the variety of living organisms present in a particular area or on Earth as a whole. It includes plants, animals, microorganisms, and their ecosystems.

Key Points:

• Includes all forms of life
• Maintains ecological balance
• Supports food chains and ecosystems
• Essential for environmental stability

Real-Life Example:
A forest containing many species of trees, birds, insects, and mammals has high biodiversity.

Answer: Variety of living organisms

Q9. Which human activity causes deforestation?

Deforestation is the large-scale removal of forests for human activities such as agriculture, urbanization, mining, and infrastructure development.

Key Points:

• Reduces forest cover
• Causes habitat loss
• Increases soil erosion
• Contributes to climate change

Real-Life Example:
Forests are often cleared to create farmland for growing crops.

Answer: Agriculture

Q10. Which gas causes global warming?

Global warming occurs when greenhouse gases trap heat in Earth’s atmosphere. Carbon dioxide (CO₂) is one of the major greenhouse gases released through human activities.

Key Points:

• Major greenhouse gas
• Produced by burning fossil fuels
• Increases Earth’s temperature
• Contributes to climate change

Real-Life Example:
Vehicles, factories, and power plants release carbon dioxide into the atmosphere.

Answer: Carbon dioxide

Q11. What is pollution?

Pollution is the introduction of harmful substances or contaminants into the environment, causing adverse effects on living organisms and natural resources.

Key Points:

• Affects air, water, and soil
• Can harm human health
• Damages ecosystems
• Often caused by human activities

Real-Life Example:
Dumping industrial waste into rivers causes water pollution.

Answer: Addition of harmful substances

Q12. Which resource is renewable?

Renewable resources are natural resources that can be replenished naturally within a relatively short period of time. Solar energy is one of the most important renewable energy sources.

Key Points:

• Available continuously
• Environment-friendly
• Reduces dependence on fossil fuels
• Sustainable energy source

Real-Life Example:
Solar panels installed on rooftops convert sunlight into electricity.

Answer: Solar energy

Q13. What is conservation?

Conservation refers to the protection, preservation, and sustainable use of natural resources to ensure their availability for future generations.

Key Points:

• Protects natural resources
• Prevents environmental degradation
• Promotes sustainable development
• Maintains ecological balance

Real-Life Example:
National parks and wildlife sanctuaries help conserve biodiversity.

Answer: Protecting natural resources

Q14. Which level is at the top of the food chain?

Tertiary consumers occupy the highest trophic level in many food chains. They usually feed on secondary consumers and have few or no natural predators.

Key Points:

• Top-level consumers
• Often carnivores
• Control populations of other organisms
• Occupy the highest trophic level

Real-Life Example:
An eagle feeding on snakes is an example of a tertiary consumer.

Answer: Tertiary consumers

Q15. Which cycle involves evaporation and rainfall?

The water cycle is the continuous movement of water between Earth’s surface and the atmosphere through processes such as evaporation, condensation, and precipitation.

Key Points:

• Maintains Earth’s water supply
• Includes evaporation and condensation
• Produces rainfall
• Essential for life

Real-Life Example:
Water from oceans evaporates, forms clouds, and returns as rain.

Answer: Water cycle

Q16. Which pollutant causes acid rain?

Acid rain is a type of precipitation that contains harmful acidic substances. It mainly forms when sulfur dioxide (SO₂) and nitrogen oxides react with water vapor in the atmosphere. Sulfur dioxide is one of the primary pollutants responsible for acid rain.

Key Points:

• Released from industries and power plants
• Reacts with water vapor in the atmosphere
• Forms sulfuric acid
• Damages plants, soil, and water bodies

Real-Life Example:
Smoke emitted from coal-based thermal power stations can release sulfur dioxide, leading to acid rain.

Answer: Sulfur dioxide

Q17. Which of the following is a non-renewable resource?

Non-renewable resources are natural resources that take millions of years to form and cannot be replenished quickly once exhausted. Coal is a major non-renewable energy source.

Key Points:

• Limited availability
• Formed over millions of years
• Used as a fossil fuel
• Cannot be replaced quickly

Real-Life Example:
Coal is burned in thermal power plants to generate electricity.

Answer: Coal

Q18. What is afforestation?

Afforestation is the process of planting trees in areas where forests did not previously exist or where forest cover has been reduced. It helps restore ecological balance and improve environmental quality.

Key Points:

• Increases forest cover
• Prevents soil erosion
• Absorbs carbon dioxide
• Supports biodiversity

Real-Life Example:
Government tree-planting programs along roadsides and barren lands are examples of afforestation.

Answer: Planting trees

Q19. Which organism is both producer and consumer?

Euglena is a unique microorganism that exhibits characteristics of both plants and animals. It can prepare its own food through photosynthesis when sunlight is available and can also consume food from external sources when necessary.

Key Points:

• Contains chlorophyll
• Performs photosynthesis
• Can consume food in the absence of sunlight
• Shows both plant-like and animal-like features

Real-Life Example:
Euglena living in ponds produces food during the day using sunlight but may feed on organic matter when light is unavailable.

Answer: Euglena

Q20. What is global warming?

Global warming refers to the gradual increase in Earth’s average temperature due to the accumulation of greenhouse gases in the atmosphere. Human activities such as burning fossil fuels and deforestation contribute significantly to this phenomenon.

Key Points:

• Caused by greenhouse gases
• Increases Earth’s temperature
• Leads to climate change
• Affects weather patterns and ecosystems

Real-Life Example:
Rising temperatures, melting glaciers, and increased heat waves observed around the world are effects of global warming.

Answer: Increase in Earth’s temperature

📚 Authority Reference

Reference: NCERT Class 12 Biology – Ecology Unit