Important Questions Class 12 Biology Chapter 16

Important Questions Class 12 Chapter 16

Important Questions for CBSE Class 12 Biology Chapter 16 – Environmental Issues

The Chapter 16 Class 12 Biology Important Questions demonstrate the exponential population growth over time that has boosted demand for many different commodities, including food, water, shelter, power, clothing, and automobiles. These needs place a heavy strain on the environment’s natural resources, which ultimately leads to contamination of the air, water, and soil.

With these Class 12 Biology Chapter 16 Important Questions, students will come to know that it has become imperative to stop the deterioration and exhaustion of our priceless natural resources without impeding the development process.

Moreover, with these Class 12 Biology Chapter 16 Important Questions, Extramarks will provide students with detailed and authentic solutions to important questions according to CBSE past year’s question papers so that students can prepare for their examination according to the CBSE syllabus.

CBSE Class 12 Biology Chapter 16 Important Questions

Study Important Questions for Class 12 Biology Chapter 16 – Environmental Issues

Q.1. Define the environment.

Ans. The environment is everything surrounding us, including living and nonliving objects both like water, soil, plants, and animals. The natural environment contributes to the support of life on earth.

Q.2. Explain deforestation.

Ans. The large-scale eradication of trees from forests or other places to make way for human activity is known as deforestation. It poses a severe threat to the ecosystem since it can lead to soil erosion, habitat destruction, biodiversity loss, and water cycle disruptions. A major factor in climate change and global warming is deforestation.

Q.3. Write down the potential larger-scale source of production for each greenhouse gas listed. What are its negative effects?

Ans. Carbon dioxide, methane, nitrogen oxide, water vapour, and other substances are examples of typical greenhouse gases. Unrestricted use of fossil fuels raises the level of carbon dioxide as a result of widespread deforestation, which promotes global warming. A few sources contributing to an increase in methane levels are waste dumps, flooded paddy fields, anaerobic methanogens, and marshy areas. Asia’s rice fields generate 90% of the world’s methane.

Q.4. Write your thoughts on electrical waste. Write about the many e-waste sources and disposal problems that arise.

Ans. Solid wastes include sewage, hospital and nursing wastes, industrial wastes, and electronic wastes. They can also be recyclable, biodegradable, or non-biodegradable. E-waste, also referred to as electronic garbage, includes mobile phones, broken laptops, and other similar electronic goods. Their sources include the imports of irreparable electronics that are common in emerging nations like China and India in exchange for the valuable metals that can be extracted from these wastes, like nickel, gold, and copper. A large amount of e-waste is burned or disposed of in landfills. In poor nations, metals are manually extracted from e-waste. Therefore, working with them exposes one to the hazardous compounds contained therein, which can cause skin ailments. Hence, the only method for treating e-waste is recycling.

Q.5. What are Ramesh Chandra Dagar in Sonipat and Ahmed Khan in Bangalore contributing?

Ans. Waste products from one process are recycled into nutrients for other processes in integrated organic farming, which is a circular, waste-free process. This permits the best possible resource utilisation and boosts production effectiveness. This is exactly what Ramesh Chandra Dagar, a farmer in Sonipat, Haryana, is doing by producing natural gas to meet the farm’s energy requirements. He combines agriculture, beekeeping, dairy management, water collection, composting, and other practices into a series of interconnected activities that support one another and enables a very profitable and long-lasting endeavour. Since cow dung is utilised as manure, there is no need to fertilise crops with chemicals. Compost, which is used as a natural fertiliser or to produce natural gas to meet the farm’s energy demands, is made from crop waste. Dagar founded the Haryana Kisan Welfare Club, which currently has 5000 farmers as members, out of his enthusiasm for disseminating knowledge and assistance on the practice of integrated organic farming.

Q.6. What are multifunctional trees? Mention the usage of any two multipurpose trees along with their botanical and regional names.

Ans. Trees that serve multiple tasks after planting are referred to as multifunctional trees. These trees serve many purposes including supplying shade, timber, fruit, food, improving the soil, etc. They provide a wide range of services and needs for people. Neem, also known as Azardicta, is a popular medicinal plant. Most of its parts including leaves, wood, fruit, and wood oil are utilised in ayurvedic remedies.

The compound azadirachtin makes the wood of this tree pest-resistant. Another significant tree is the coconut palm, which is botanically referred to as Cocos Nucifera, a member of the Palmae family and serves a number of purposes, including providing wood, oil, food fibre, and commercial, medical, and fibre purposes. The Morinaoleifera and Gliricidia septum, used for fences in Central America, is another versatile tree. It supplies fuel for the fire and fixes nitrogen in the atmosphere. Its leaves are delicious and frequently used for shade and animal fodder.

Q.7. Define ozone shield.

Ans. The ozone layer in the atmosphere functions as a UV absorber, shielding the earth from the damaging effects of radiation. The term “ozone layer” or “ozone shield” refers to the uppermost part of the atmosphere that is covered by ozone.

FAQs (Frequently Asked Questions)

1. Define snow blindness.

The cornea is inflamed as a result of high ultraviolet-B radiation absorption.

2. How are ozone shields impacted by ozone-depleting substances?

When chlorine atoms and bromine atoms come into contact with ozone molecules in the stratosphere, they are destroyed. Over 100,000 ozone molecules may be harmed by a single chlorine atom before it is expelled from the stratosphere. Ozone might disappear more quickly than it could be produced organically.

3. Why does India's National Forest Commission advise having more forest cover on hills than in plains?

This is due to the fact that sizable forested hillsides prevent soil erosion, percolation, and recharge groundwater. It encourages the preservation of the indigenous flora and fauna of the hills while monitoring landslides and other natural disasters.

4. What is hybrid vehicle technology?

It is a technology that allows cars to run on either compressed natural gas or gasoline. Because CNG is a green and clean fuel, it can help reduce environmental pollution while also conserving fossil fuels like gasoline.