Free Pollution and Conservation MCQs with Answers

21. Chemicals used for destroying agricultural competitors are known as:

• A. Antibiotics
• B. Pesticides
• C. Disinfectants
• D. Chemotherapeutic agents

Explanation: Pesticides are a class of chemicals that are used to kill crop-eating insects, unwanted weeds etc. Insecticides, herbicides, nematicides; they all come under the umbrella of pesticides.

22. The largest demand of energy is generally fulfilled by

• A. Hydroelectric power
• B. Nuclear power
• C. Solar energy
• D. Fossil fuels

Explanation: Fuels that are generated very deep under the earth from the debris of plants and animals, which existed millions of years ago, are called fossil fuels. Coal, oil and natural gases are fossil fuels. Fossil fuel energy sources, such as coal, natural gas, and oil are used to meet energy demands for much of the world. Fossil fuel accounts for 84% of world's primary consumption while hydroelectric power accounts for 6%, renewables for 5%, and nuclear power for 4%.

23. Food is renewable resource due to:

• A. Mechanical forming
• B. Improved crop varieties
• C. Continuous photosynthesis
• D. Pest control

Explanation: Food is considered a renewable resource primarily because of continuous photosynthesis, which allows plants to convert sunlight into energy, produce food, and support life on Earth. This natural process ensures that plants, which form the base of most food chains, can constantly produce food. Options A, B, and D refer to techniques and methods that enhance food production but do not inherently make food renewable. Mechanical forming prepares land for cultivation, improved crop varieties increase productivity, and pest control protects crops, but none of these address the natural regenerative process of photosynthesis.

24. Which of the following does not bring erosion of soil?

• A. Carolers forming
• B. Extensive ploughing
• C. Moderate grazing
• D. Heavy grazing

Explanation: Moderate grazing refers to controlled or balanced grazing practices where the number of livestock and their grazing duration are managed in a sustainable manner. It involves maintaining a healthy vegetation cover and avoiding overgrazing. This practice can actually be beneficial for the soil and ecosystem as it helps in maintaining biodiversity, nutrient cycling, and organic matter accumulation.

25. Gas·evolved in bioconversion of solid waste is:

• A. Methane
• B. Sulpher dioxide
• C. Nitrogen dioxide
• D. Ethane

Explanation: Solid wastes are biologically converted into value added products by physiological action of microorganisms. These processes occur under controlled environmental condition. It could be in the form of submerged fermentation or as solid-state fermentation technology. The gas released during this conversion is methane and carbon dioxide. Usually, carbon dioxide is released during aerobic conversion of solid waste while methane is released during anaerobic conversion of solid waste.

26. All of the following are non-renewable resources of energy EXCEPT:

• A. Forests
• B. Iron
• C. Petroleum
• D. Natural gas

Explanation: Forests are not considered non-renewable resources of energy. Forests have various uses and can provide energy through biomass, they are renewable resources that can be managed and replenished.

27. The ozone layer present in the

• A. troposphere
• B. stratosphere
• C. mesosphere
• D. atmosphere

Explanation: Ozone Layer: It is a thin part of Earth's atmosphere that absorbs almost all of the sun's harmful ultraviolet light. EARTH'S ATMOSPHERIC LAYERS: Earth's atmosphere has a series of layers, each with its own specific traits. Moving upward from ground level, these layers are called the troposphere, stratosphere, mesosphere, thermosphere, and exosphere. The Ozone layer is around 15-30 km above the earth's surface. From the above diagram, we know that this region lies in the stratosphere. Thus, option 'B' is correct.

28. The area where ultra voilet radiations are intense is the

• A. Alphine forests
• B. Boreal forests
• C. Arctic tundra
• D. Alpine tundra

Explanation: Among all the options, alpine tundra is at the highest elevation (about 12000 ft and above), and it has the most sunlight hours. Thus, the UV level in the alpine tundra is the highest.

29. All of the following are non renewable resources of energy except:

• A. Forest
• B. Nuclear power
• C. Oil
• D. Coal

Explanation: Non-renewable resources are natural resources that cannot be easily replenished or regenerated within a short period of time. These resources include fossil fuels like coal, oil, and natural gas, as well as minerals like copper, gold, and uranium. Since they are finite and take millions of years to form, their availability is limited. It's important for us to use non-renewable resources wisely and explore alternative, renewable sources of energy to ensure a sustainable future.