Class 12 Biology Important Chapter 17 Environmental Issues Solutions English Medium As Per The New Syllabus to each chapter is provided in the list so that you can easily browse through different chapters ASSEB Class 12 Biology Important Solutions in English and select need one. AHSEC Class 12 Biology Additional Notes Download PDF. HS 2nd Year Biology Additional Solutions.
Class 12 Biology Important Chapter 17 Environmental Issues
Also, you can read the NCERT book online in these sections Solutions by Expert Teachers as per Central Board of Secondary Education (CBSE) Book guidelines. ASSEB Class 12 Biology Additional Question Answer are part of All Subject Solutions. Here we have given HS 2nd Year Biology Important Solutions English Medium for All Chapters, You can practice these here.
Environmental Issues
Chapter: 17
| IMPORTANT QUESTION AND ANSWER |
Answer the Following Question:
1. Name any one gaseous pollutant.
Ans: Sulphur dioxide (SO₂).
2. What does PM 2.5 stand for?
Ans: Particulate matter with diameter less than or equal to 2.5 micrometers.
3. Which act was passed in India in 1986 to protect the environment?
Ans: Environment (Protection) Act, 1986.
4. What is BOD?
Ans: Biochemical Oxygen Demand – the amount of oxygen needed by microorganisms to decompose organic matter.
5. Name any one radioactive pollutant.
Ans: Uranium.
6. What is eutrophication?
Ans: Excessive nutrient enrichment of water bodies leading to algal blooms.
7. Name the movement where people hugged trees to prevent cutting.
Ans: Chipko Movement.
8. What is meant by PM 2.5 and why is it dangerous?
Ans: PM 2.5 refers to particulate matter of size 2.5 micrometers or less. These fine particles can be inhaled deep into the lungs, causing respiratory problems, lung inflammation, and even premature death due to chronic exposure.
9. What is the principle behind the working of an electrostatic precipitator?
Ans: Electrostatic precipitators remove particulate matter by charging the dust particles using high-voltage electrodes. These charged particles are then attracted to grounded plates, thus removing them from industrial emissions.
10. What is algal bloom?
Ans: Algal bloom is the excessive growth of planktonic algae due to nutrient enrichment (mainly nitrates and phosphates) in water bodies. It leads to oxygen depletion and fish mortality, degrading water quality.
11. What is eutrophication?
Ans: Eutrophication is the natural or accelerated aging of a lake due to excess nutrients, resulting in algal growth, oxygen depletion, and decline of aquatic organisms.
12. What is the “Terror of Bengal”? Why is it called so?
Ans: Eichhornia crassipes (Water Hyacinth) is called the “Terror of Bengal” because of its uncontrolled growth in water bodies, leading to blockage of waterways, oxygen depletion, and death of aquatic life.
13. What are e-wastes? How are they hazardous?
Ans: E-wastes are discarded electronic devices (computers, phones, TVs). They contain toxic heavy metals like lead, mercury, cadmium, which can pollute soil and water and harm human health when not disposed properly.
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