NEET Biology Environmental Issues Important Questions Set 01

These Class 12 NEET Biology important questions on Environmental Issues give 45 questions with step-by-step answers, arranged as very short, short and long answer types, as asked in school and board examinations. They help NEET aspirants revise the definitions, structures, differences and key terms of the chapter.

Very Short Answer Type Questions

Question 1. In which year was the air (Prevention and Control of Pollution) act amended to include noise as air pollution?
Answer: 1987.

Question 2. Name the city in our country where the entire public road transport runs on CNG.
Answer: Delhi.

Question 3. What is the raw material for polyblend?
Answer: Bituminous coal and polythene.

Question 4. Expand FOAM.
Answer: Friends of Arcata Marsh.

Question 5. What is cultural eutrophication?
Answer: The accelerated rate of eutrophication or natural ageing of lakes mediated by man's activities like effluents from industries and home.

Question 6. List any two adverse effect of particulate matter on human health.
Answer: (i) Difficulty in breathing.
(ii) Irritation and inflammation of lungs.

Question 7. What is the best device which removes particulate matter from air?
Answer: Electrostatic precipitator.

Question 8. When was the Environment Protection Act passed?
Answer: 1986.

Question 9. Name the catalyst used in catalytic converters.
Answer: Platinum, palladium and rhodium.

Question 10. Name the greenhouse gases.
Answer: CO₂, CFC, CH₄ and N₂O.

Short Answer Type Questions

Question 11. Explain biomagnification.
Answer: It refers to increase in concentration of toxicant at successive trophic levels. This happens because a toxic substance accumulated by an organism cannot be metabolised and excreted.

Question 12. Why are trees and shrubs planted near walls of buildings?
Answer: The plants growing near the boundary wall act as barriers for sound pollution and acts as dust catches.

Question 13. What are the features of septic water?
Answer: (i) Organic pollution
(ii) Dissolved oxygen low
(iii) High BOD

Question 14. What are the three major kinds of impurities in domestic water?
Answer: (i) Suspended particles – Sand, silt and clay
(ii) Colloidal particles – Faecal matter, cloth and paper fibre.
(iii) Nutrients

Question 15. What is algal bloom?
Answer: Excessive growth of planktonic or free floating algae which imparts a distinct colour to water bodies, causes deterioration of water quality and fish mortality.

Question 16. What is the main effect of sewage from hospitals?
Answer: It contains many undesirable pathogenic microorganisms whose disposal without proper treatment may cause out break of many diseases like dysentery, typhoid, jaundice, cholera.

Question 17. What is thermal pollution?
Answer: Heated or thermal waste waters flowing out of electricity generating units is thermal power plants, are the source of thermal pollution. It reduces the number of organisms sensitive to high temperature and may enhance the growth of fishes and plants in extremely cold areas but only after causing damage to indigenous species.

Question 18. What are the main objectives of FOAM?
Answer: (i) Treatment of water.
(ii) Maintaining high level of biodiversity

Question 19. What are Ecosan toilets?
Answer: Ecosan toilets is a sustainable system of handling human excreta using dry composting toilets. This is a practical, hygienic, efficient and cost effective solution to human waste disposal.

Question 20. What are e-wastes? What is their best method of disposal?
Answer: Irrepealable computers and other electronic goods are e-wastes. Disposal methods:
(i) Buried in land fills.
(ii) Incinerated
(iii) Exported to developing countries

Question 21. What is the best method to combat soil pollution?
Answer: Organic farming, where waste products from one process are cycled as nutrients for other process. This allows maximum utilisation of resources and increase the efficiency of production.

Question 22. How has DDT caused decline in bird population?
Answer: DDT concentration increases at each trophic level which is called as biomagnification. This is highest at the level of fish eating birds. DDT interferes with its calcium metabolism, causes thinning of eggs shells and decline in bird population.

Question 23. What is snow blindness?
Answer: In human eye cornea absorbs UV-B radiation and a high dose of UV-B causes inflammation of cornea called snow blindness which is permanent damage to cornea.

Question 24. What is joint forest management?
Answer: The idea of the government to work closely with local communities for protecting and managing forests. In return for their services to the forest they get benefit of various forest products like fruits, gum, rubber, medicine and thus forests are conserved in sustainable manner.

Question 25. What are the two main causes of radioactive pollution?
Answer: (i) Accidental leakage as in Three Mile Islands and Chernobyl Accident.
(ii) Non-safe disposal of radioactive wastes.

Question 26. What was the objective of Montreal Protocol.
Answer: To control the emission of ozone depleting substances.

Question 27. List two examples of improper resource utilization.
Answer: (i) Soil erosion and desertification.
(ii) Water logging and soil salinity due to faulty irrigation methods.

Question 28. Define slash and burn agriculture.
Answer: This method is practised in the north eastern states of India. The farmers cut down trees of the forest and burn the plant remains. The ashes used as fertiliser and the land is used for farming or cattle grazing.

Question 29. What is reforestation?
Answer: It is the process of restoring a forest that once existed but was removed at some point of time in past.

Question 30. Describe Chipko Movement.
Answer: This movement was started to protect the forests of India, in Garhwal Himalayas. In 1974 the local women, showed enormous bravery in protecting trees from the axe of contractors by hugging them.

Long Answer Type Questions

Question 31. What is organic farming. Discuss the benefits of organic farming.
Answer: Integrated organic farming is a cyclical zero waste procedure where waste products from one process are cycled in as nutrients for other processes. This allows maximum utilisation of resource and increase in efficiency of production. It includes bee keeping, dairy management, water harvesting, composting and agriculture in a chain of processes which support each other and allow an extremely economical and sustainable venture. There is no need to use chemical fertilisers for crops as cattle dung are used as manure. Crop waste is used to create compost which can be used as natural fertiliser or can be used to generate natural gas for satisfying the energy needs of farm.

Question 32. Write short note on electronic waste. List the various sources of e-wastes and the problems associated with disposal of e-waste.
Answer: Discarded unusable electronic gadgets such as computers, mobile phones circuits, television sets etc. form electronic waste. These contain harmful toxic substances like heavy metals to which unskilled manual workers remain exposed.

Question 33. What are the basic characteristics of a modern land fill site? List any three and mention the reasons for their use.
Answer: (i) Plastic or clay lines which contain leachate things.
(ii) Covering of waste to prevent its blowing away by wind.
(iii) Installation of land fills gas extraction system to extract gas for power use.

Question 34. How does an electrostatic precipitation work?

Answer:

A well-labelled diagram should show these parts: Discharge corona; Negatively charged wire; Dirty air; Clean air; Dust particles; Collection plate grounded; Electrostatic precipitator.

This device removes 99% particulate matter. It has electrode wires that are maintained at several thousands volts which produce a corona that releases electrons. These collecting plates are grounded and attract the charged dust particles. The velocity of air between plates must be low enough to allow dust to fall.

Question 35. W.r.t. following diagram answer the following questions
Fish-eating birds (DDT 25 ppm)
Large fish (DDT 2 ppm)
Small fish (DDT 0.5 ppm)
Zooplankton (DDT 0.04 ppm)
Water (DDT 0.003 ppb)
Fig. : Biomagnification of DDT in an aquatic food chain
(i) What ecological term is used to describe DDT accumulation?
(ii) List the effect on birds.
(iii) Will DDT accumulation lead to eutrophication?
(iv) Does it effect BOD.
(v) Name disease caused by accumulation of any heavy metal.
Answer: (i) Biomagnification
(ii) It interferes with calcium metabolism and causes thinning of egg shells.
(iii) No
(iv) No, as it is non-biodegradable.
(v) Minamata disease due to mercury.

Question 36. Write a short note on various environmental laws.
Answer: (i) Environment Protection Act 1986.
(ii) Air (Prevention and Control Pollution Act) 1981 (Amended in 1987 to include noise as an air pollutant).
(iii) Water prevention and control of Pollution Act 1974.

Question 37. Write a short note on
(a) Greenhouse effect
(b) Ozone depletion
Answer: (a) Greenhouse effect : The main greenhouse gases are :
(i) CO₂ : It contributes to 60% of total global warming. It is produced due to excessive combustion of fossil fuels biomass burning and deforestation.
(ii) CH₄ : It contributes to 20% of total global warming. Major source are paddy field, enteric fermentation in cattle and wetlands.
(iii) CFC : They are synthetic compounds of carbon and halogen used in aerosol refrigeration, air conditioner etc. It contributes 14% of global warming.
(iv) N₂O : It contributes to 6% of global warming. It comes from burning of N₂-rich fuel.
(b) Ozone hole formed over Antarctica : CFC's and other ODs released by Europe, Russia, Japan and North America reach the stratosphere. They drift towards poles and reach there below the advert of winter. In winter months the temperature over Antarctica is extremely low (–85°C). It results in the formation of ice clouds. Antarctica air now does not mix with the rest of the global air. It circulates along the polar vortex. Ice clouds provide catalytic surface for CFC's and other ODs to release chlorine and other radicals that can react with ozone. However during winter's polar areas do not receive sunlight and no catalytic breakdown of ozone occurs. With the beginning of spring availability of sunlight causes release of chlorine from CFC's. It reacts catalytically with ozone and degrades it. As a result ozone concentration decreases drastically producing the effect of ozone hole. As the summer approaches the hole disappear due to free mixing of antarctic air with the rest of the world. UV radiation of wavelength shorter than UV-B, are almost completely absorbed by Earth's atmosphere, given that the ozone layer is intact. But, UV-B damages DNA and mutation may occur. It causes aging of skin, damage to skin cells and various types of skin cancers. In human eye, cornea absorbs UV-B radiation, and a high dose of UV-B causes inflammation of cornea, called snow-blindness cataract.

Question 38. Fill in the blanks
(a) Non biodegradable pollutant are created by ______ .
(b) According to CPCB particles that are responsible for causing great harm to human health are of ______ diameter.
(c) CNG is ______ .
(d) Worlds most problematic weed ______ .
(e) ______ and ______ cause biomagnification.
Answer: (a) Humans
(b) 2.5 μm
(c) Butane
(d) Elcchornia
(e) Hg, DDT

Question 39.

Match the columns

Answer:

a(iv), b(v), c(i), d(iii), e(ii)

Question 40. Discuss the effect of sewage on important characteristics of water.
Answer: A well-labelled diagram should show these parts: Fish kill; Reappearanceof disappearanceof and clean water clean water organism; Dissolved oxygen; Concentration; BOD; Direction of flow; Sewage discharge.

Question 41. Explain how people of Arcata California have controlled water pollution.
Answer: The people of Arcata along with Humboldt University have created an integrated waste water treatment within a natural system. The cleaning occurs in two stages.
(a) Conventional sedimentation, filtering and chlorine treatments.
(b) Development of six connected marshes over 60 hectares of marshland. Plants, algae, fungi and bacteria were seeded into this area which neutralise, absorb and assimilate pollutants.

Question 42. Discuss the effects of sound pollution. How can we combat noise pollution?
Answer: It causes sleeplessness, increased heart beat, altered breathing pattern stress. Steps which can reduce noise pollution.
(i) Sound absorbent materials in industries.
(ii) Honking free zones.
(iii) Permissible sound levels of crackers and loudspeakers.

Question 43. What are (a) Ecosan toilets and (b) Polyblend?
Answer: (i) It is a sustainable system for handling human excreta using dry composting toilets. It is a practical, hygienic, efficient and cost effective solution to human waste disposal.
(ii) Polyblend is a fine powder of recycled modified plastic. It is mixed with bitumen to lay roads.

Question 44. What is the objective of Montreal Protocol and Kyoto Protocol?
Answer: Montreal Protocol: Protection to stratospheric ozone by agreeing to limit the production of use of ODS, phasing out of ODS and helping the developing countries to implement use of alternatives of CFC. Kyoto Protocol : Mitigate climate changes. It requires countries to take appropriate measures to reduce their over all greenhouse gas emission to a level at least 5% below 1990.

Question 45. How can soil degradatation be controlled?
Answer: (i) Reforestation
(ii) Crop rotation
(iii) Adequate drainage
(iv) Artificial bonds or covering area with suitable vegetation.