CBSE Class 12 Biology Environmental Issues Question Bank. There are many more useful educational material which the students can download in pdf format and use them for studies. Study material like concept maps, important and sure shot question banks, quick to learn flash cards, flow charts, mind maps, teacher notes, important formulas, past examinations question bank, important concepts taught by teachers. Students can download these useful educational material free and use them to get better marks in examinations. Also refer to other worksheets for the same chapter and other subjects too. Use them for better understanding of the subjects.
BIOLOGY
1. Why should the velocity of air between the plates of an electrostatic precipitator be low?
2. PM2.5 is responsible for causing greatest harm to human health. What is it? How is it harmful?
3. What is the noise level that can cause permanent impairment of hearing ability of human beings?
4. Why was the Montreal Protocol signed?
5. Jhum cultivation has been in practice from earlier days, but its considered more problematic these days. Why?
6. A radiation causes ageing of skin, skin cancer, and inflammation of cornea called snow blindness. It also damages DNA. Name the radiation.
7. Landfills are not much a solution for getting rid of solid wastes. Why?
8. Electrostatic precipitator can remove over 99% particulate matter present in exhaust from a thermal power plant. How?
9. Why is a scrubber used? Which spray is used on exhaust gases passing through a scrubber?
10. There is a sharp decline in dissolved oxygen downstream from the point of sewage discharge. Why? What are its adverse effects?
11. Catalytic converters use expensive metals as catalysts.
(a) Name the metals generally used.
(b) What precaution should be observed while using catalytic converter?
12. What are e-wastes? Why are they creating more problems in developing countries in comparison to developed countries?
13. Water logging and salinity are some of the problems that have come in the wake of Green revolution. How does water logging create problems of salinity?
14. What is the relationship between BOD, micro-organisms and amount of biodegradable matter?
15. Deforestation is creating a lot of problems in the environment. List the consequences of deforestation.
16. Enlist four harmful effects caused to the humans living in areas having polluted air. Suggest two measures to reduce air pollution.
17. People have been actively participating in the efforts for the conservation of forests.
(i) Name the award instituted in respect of Amrita Devi to promote such fforts.
(ii) Name the movement launched to protect the trees by hugging them.
(iii) Name the step Government of India has undertaken in 1980.s to work closely with the local communities for protecting and managing forests.
18. Pollutant released due to human activities (like effluents from industries and homes) can radically accelerate the ageing process of the water body.
(a) Explain how does this process occurs during natural ageing of lake.
(b) Give the term used for accelerated ageing of water bodies. Also give the term used for the natural ageing of lake.
ENVIRONMENTAL ISSUES
(QUESTION BANK)
19. In Arcata, the town’s people have created an integrated waste water treatment process within a natural system. A citizen group called FOAM helps in upkeep of this project.
(a) What are the main steps in waste water management done in this way?
(b) Ecosan. in Kerala and Sri Lanka is also an initiative for water conservation. How?
20. What are the contribution of Ahmed Khan in Bangalore and Ramesh Chandra Dagar in Sonipat?
21. Since the use of polybags has become so rampant in our day to day life, it is impossible to go back to non-plastic era. Today, the plastic menace has spread from cities to small towns and village. They are “Garbage Forever”.
i) What are the harmful effects of using polybags?
ii) In your opinion, what steps should be taken to solve this problem?
22. Nowadays, we see that people use CDs & DVDs for storing information, movies and songs.
i) Do you think these things create pollution?
ii) Which values are expressed, on the basis of information?
ENVIRONMENTAL ISSUES
(ANSWER KEY)
1 To allow the dust to fall.
2 PM2.5 stands for particulate matter of size 2.5 micrometres or less in diameter. It’s 1m responsible for causing greatest harm to human health as it can be inhaled deep into lungs and cause breathing problems.
3 150 dB or more
4 To control emission of ozone depleting substances
5 Enough time gap is not being given for the natural process of recovery of land from the effect of cultivation
6 Ultraviolet B rays (UV-B rays)
7 Landfill sites are getting filled very fast due to large amount of garbage generation. Also underground water resources may get polluted due to seepage of chemicals
8 Electrode wire at thousand volts, produce corona to release electrons,electrons attach to dust particules giving them net negative charge, charged dust particules attracted/collected by collecting plates which are grounded
9 To remove gases like sulphur dioxide. Spray of water or lime is used
10 Following discharge of sewage into river, micro organisms involved in biodegradation of organic matter present in sewage consume more oxygen.
This cause mortality of fish and other aquatic creature
11 (a) Catalysts : platinum - palladium and Rhodium
(b) Motor vehicles equipped with catalytic converters should use unleaded petrol as lead inactivates the catalysts.
12 a) Irrepairable computers and other electronic wastes.
(b) Recycling in developing countries involves manual participation thus exposing workers to toxic substances. In developed countries its mechanised so less dangerous
13 Water logging draws salt to surface of soil. Salt deposited on land surface as a thin crust or at the roots of the plants
14 Increase in amount of biodegradable matter leads to rapid multiplication of micro organisms to degrade it, thereby increasing BOD level of the water body.
15 Enhanced CO2 concentration in atmosphere, Loss of biodiversity ,Soil erosion Desertification ,Disturbed hydrological cycles.
16 .Breathing problems, irritation and inflammation, Damage to lungs, Premature death. Reduce emission from automobile exhaust , Growing more trees
17 (i) Amrita Devi Bishnoi Wildlife Protection Award. (ii) Chipko movement (iii) Joint Forest Management (JFM).
18 a) The phenomeon is eutrophication. More nutrients in water, aquatic life increases organic remains deposited on lake bottom, lake grows shallower and warmer, gradually transforms into land due to deposition of silt and organic debris.
(b) Cultural or Accelerated eutrophication ,Natural ageing is Eutrophication
19 a) Conventional sedimentation, filtering and chlorine treatment. Absorption and assimilation of pollutants by algae fungi and bacteria.
(b) .Ecosan. derived from ecological sanitation. Handling human excreta using dry composting toilets. Its practical, hygienic and cost effective method.
20 a)Polyblend ,a fine powder of recycled modified plastic is mixed with bitumen & used to lay roads. This increases bitumen water repellent properties & increase road life by a factor of three
b) Integrated organic farming is a cyclical, zero waste procedure, where waste from process are cycled in as nutrients for other process. He included bee keeping, dairy management, water harvesting composting and agriculture in s chain of processes.
21 (I) Non degradable, choke our sewage & drainage system, stray cattle eats it & choke its digestive system
(II) Using paper,jute,cloth bags. Minimise the use voluntarily. Segregation of biodegradable & non-biodegradable material to safe disposal. Educating
people on health risk, production of biodegradable plastic bags by mixing cellulose during their manufacturing.
22 Yes, these contain heavy metals & toxic substances. As the technology is changing these products are replaced by i pods, pen drives. They constitute e-waste.
Please click the link below to download CBSE Class 12 Biology Environmental Issues Question Bank.
