UP Board Class 10 Biology For How Do Our Activities Affect The Environment Question and Answers

How Do Our Activities Affect The Environment Questions

India today is facing the problem of overuse of resources, contamination of water and soil, and lack of methods of processing waste. The time has come for the world to say goodbye to “single-use plastics”.

Steps must be undertaken to develop environment-friendly substitutes, effective plastic waste collection, and methods of disposal. Indore treated 15 lakh metric tonnes of waste in just 3 years, through biomining and bioremediation techniques.

Bioremediation involves introducing microbes into landfills to naturally ‘break’ it down. Biomining involves using trommel machines to sift through the waste to separate the ‘soil’ and the waste component.

The city managed to chip away 15 lakh metric tonnes of waste at the cost of around < 10 crore. A similar experiment was successfully carried out in Ahmedabad also.

Question 1. What is ozone and how does it affect any ecosystem?
Answer: Ozone is a molecule formed by three atoms of oxygen O3. Normal oxygen is 02 or formed of two atoms. Ozone is toxic if present in the lower atmosphere or troposphere.

It destroys the photosynthetic cells of plants and causes injury to mucous membranes, eye irritation, and internal hemorrhage. However, ozone present in the stratosphere is highly useful.

It protects the ecosystem from harmful UV radiations (UVC 100 – 280 nm, UVB 280 – 320 nm) by dissipating their energy. In case of ozone depletion, there would be a rise in skin cancers, cataracts, photobombing, a decrease in immunity, a fall in photosynthetic efficiency, and death of larvae.

Question 2. How can you help in reducing the problem of waste disposal? Give any two methods.
Answer: The following two methods can help in reducing the problem of waste disposal:

1. Recyclable Waste. It should be separated from the rest ofthe garbage. Recyclable waste includes paper, cardboard, polythene, plastic, glass, metallic cans, etc. They are picked up by rag pickers for selling them to factories for recycling.
2. Nonrecyclable Biodegradable Waste. It includes stale food, leftover food, vegetable peelings, fruit peelings, used tea leaves, prunings of the kitchen garden, etc. It can be converted into compost for your kitchen garden, or school garden or handed over to municipal waste disposal workers.

How Do Our Activities Affect The Environment Short Answer Type Questions

Question 1. What is ozone? How does it protect the organisms on the earth?
Answer: Ozone is a triatomic molecule that is formed by three atoms of oxygen, 03. Ozone present in the stratosphere filters out harmful high-energy UV radiations and thus protects the organisms on the earth from them.

Question 2. We often observe domestic waste decomposing in the by-lanes of residential colonies. Suggest ways to make people realize that the improper disposal of waste is harmful to the environment
Answer: Domestic waste is often thrown outside each home or at one corner of the street. This attracts pigs, stray cattle, and dogs who scatter the waste that starts decomposing and emitting a foul smell. The practice is unhygienic. Domestic waste must be segregated and the segregated waste must be lifted by municipal staff.

Question 3. Explain how ozone is formed in the atmosphere. How does it protect living beings from harmful radiations of the sun?
Answer: Ozone is formed in the stratosphere from O₂ by the action of energy UV radiations.

⇒ \(\begin{gathered}
\mathrm{O}_2 \xrightarrow{\mathrm{UV}}[\mathrm{O}]+[\mathrm{O}] \\
\mathrm{O}_2+[\mathrm{O}] \longrightarrow \mathrm{O}_3 \text { (ozone) }
\end{gathered}\)

Ozone present in the stratosphere also dissipates the energy of harmful UV radiation. The latter, therefore, do not reach the earth.

Question 4. Why is the Government of India imposing a ban on the use of polythene bags? Suggest two alternatives to these bags and explain how this ban is likely to improve the environment.
Answer: Polythene is non-biodegradable. Discarded polythene bags choke drains, kill animals feeding on garbage, and pile up. They are being replaced by cloth/jute and paper bags. Cloth/jute bags can be used again and again. Along with paper bags, they are biodegradable.

Question 5. Recycling of paper, metal, plastic, and e-waste is done in most places. Mention the positive impact of this recycling process on the environment.
Answer: There will be less exploitation of resources in forming newer articles.

There will be less pollution as the recyclable articles are picked up as soon as they are discarded.

Question 6. It is said that there is a need to put a complete ban on the products containing aerosols. What are aerosols? Why is there a demand to ban them?
Answer: Aerosols are propellant gases that are used to release substances such as a fine spray, for Example perfumes, and deodorants. The gases used to be chlorofluorocarbons. Since they have strong ozone-depleting properties, there clamor for banning them. Chlorofluorocarbons have now been replaced by isobutene or methyl propane.

Question 7. In order anto individual so ? can contribute by becoming environmentally friendly. What practice
Answer:

1. Use repeatedly reusable cloth bags instead of polythene bags.
2. At home separation of biodegradable and nonbiodegradable wastes.
3. Employment of containers used in packing at home, instead of throwing them after taking out the contained edibles.

Question 8. Damage to the ozone layer is a cause of concern.” Justify the statement. Suggest any two steps to limit this damage.
Answer: The ozone layer present in the stratosphere has thinned out by more than 8%. It has resulted in a 15-20% increased penetration of harmful UVB radiations reaching the earth.

They are causing increased skin cancers, snow blindness, cataracts, a fall in immunity, reduced photosynthesis, and a higher number of mutations.

Steps to Limit Damage:

1. Stoppage of the use of chlorofluorocarbons.
2. Stoppage of the use of halons.
3. Replacing the ODS with safer chemicals.

Question 9. List 2/3 changes in habits that people must adopt to dispose of non-biodegradable waste to save the environment.
Answer:

1. Use of cotton and jute bags for shopping.
2. Segregation of household waste into biodegradable and non-biodegradable and placing them in separate bins.
3. Adoption of three ‘Reduce, reuse, and recycle.

Question 10. Suggest two measures to manage the garbage we produce.  =As an individual what can be done to generate the least garbage? Give two points.
Answer:

Management of Garbage.

1. Separation of garbage into biodegradable and nonbiodegradable, recyclable, and nonrecyclable portions.
2. Handing over the recyclable garbage to rag pickers, and others to waste collectors.

Generate No Garbage.

1. Use cloth bags or jute bags for shopping. Say no to polythene or plastic bags.
2. Reuse glass and metallic containers instead of throwing them.

Question 11. How is ozone formed in the upper atmosphere? State its importance. What synthetic chemicals are responsible for the drop in the amount of ozone in the upper atmosphere? How can the use of these chemicals be reduced? Write one harmful effect of ozone depletion. Why did the amount of ozone in the atmosphere drop sharply in the 1980s?
Answer: Ozone is formed in the upper atmosphere or stratosphere from 02 by the action of high energy UV radiations

⇒ \(\begin{aligned}
& \mathrm{O}_2 \xrightarrow{\mathrm{UV}}[\mathrm{O}]+[\mathrm{O}] \\
& \mathrm{O}_2+[\mathrm{O}] \longrightarrow \mathrm{O}_3 \text { (ozone) }
\end{aligned}\)

Ozone present in the stratosphere dissipates the energy of harmful UV radiations ( 1 00-320 nm). The latter, therefore, do not reach the earth.

However, certain synthetic and other chemicals destroy the same, for example chlorofluorocarbons, and halons. They are called ozone-depleting substances (ODS). To the ozone layer, the use of ODS has to be reduced and leakage of these substances prevented.

Alternative chemicals that do not harm the ozone are being searched to replace the ODS. Cb) Release of ozone-depleting substances like CFCs from refrigerators, air conditioners, foam manufacturing industry, fire extinguishers, and aerosols. Harmful Effect of Ozone Depletion. Skin Cancer, Snow blindness.

Question 12. Complete the following table

Answer:

1. O₂
2. O₃.
3. Breathing
4. Absorbs harmful UV radiations.

Question 13. Kulhads (disposable cups made of clay) and disposable paper cups, both are used as alternatives to disposable plastic cups. Which one of these can be considered a better alternative to plastic cups and why?
Answer: Disposable paper cups are a better choice as they are biodegradable and do not harm the ecology. Kulhads which are made of clay deprive the fields of their fertile topsoil.

Question 14. Why is the ozone layer getting depleted at the higher levels of the atmosphere? Mention harmful effects caused by its depletion.
Answer: The ozone layer present in the upper atmosphere has been getting depleted due to synthetic chemicals emanating from the earth, viz. chlorofluorocarbons (used in refrigeration) and halons used in fire extinguishers). They release chlorine which reacts with ozone breaking it into oxygen. Harmful Effect. More UV radiation reaches the earth. They cause skin cancer.

Question 15 What are decomposers? State the role of decomposers in the natural replenishment of the soil. Why are decomposers not helpful in decomposing plastic waste?
Answer: Decomposers do not possess enzymes for digestion on the breakdown of plastics

Question 16. State two methods of effective plastic waste collection in your school.
Answer: Use separate bins for recyclable waste, plastic waste, and biodegradable waste.

Question 17. Name any two uses of “single-use plastic” in daily life.
Answer:

• Packaging of water, milk, food, biscuits, etc.
• Formation of disposable articles like bowls, tumblers, plates, forks, spoons, etc.

Question 18. If we discontinue the use of plastic, how can an environmentally friendly substitute be provided?
Answer: Use thick glazed paper, jute or cloth, cardboard, metallic utensils, and earthen pots.

Question 19. Do you think microbes will work similarly in landfill sites as they work in the laboratory? Justify your answer.
Answer: Yes, microbes will work similarly in laboratory and waste dumps provided the conditions of the two are similar.

How Do Our Activities Affect The Environment Long Answer Type Questions

Question 1.

1. What is ozone? How is it formed in the atmosphere? Explain with equations.
2. How is the ozone layer useful?
3. Name the substances responsible for the depletion of the ozone layer.

Answer: Chlorofluorocarbons (CFCs), halon, carbon tetrachloride, methyl; chloroform, methyl bromide, bromochloromethane.