Frank Solutions for Chapter 22 Sources of Waste Class 9 Biology ICSE
Exercises
1. Give two examples of domestic wastes.
Answer
Examples of domestic waste are left over food items, faeces and urine, broken nails. (Write any two)
2. What is a waste?
Answer
Waste is a product of human activity, generated from a great variety of sources.
3. What is garbage?
Answer
Garbage refers to refuse consisting largely of easily decomposable and putrefying organic (animal and vegetable) waste.
4. Give two examples of commercial waste.
Answer
Waste paper, empty printer cartridges, boxes and packaging, scrap metal etc. (Write any two)
5. What are the basic sources of wastes?
Answer. The basic sources of waste are:
- Kitchen
- Industry
- Agricultural land
- Municipality
- Offices
6. What kind of waste causes viral and bacterial disease transmission?
Answer
Human waste
7. Name one kind of industry that produces hazardous wastes?
Answer
Construction unit
8. What does sewage comprise of?
Answer
Sewage is a complex mixture of many distinctive chemicals. It has high concentrations of ammonium nitrate, phosphorous and many dissolved solids.
9. What are the hazardous wastes generated from agricultural wastes?
Answer
Crop residues, fertilizers, insecticides, herbicides and farmyard waste.
10. Give the importance of sound sewage system.
Answer
Sound sewage system prevents environmental pollution and requires efficient management of collection, treatment and recycling or safe disposal of sewage. It also prevents serious health hazards including viral and bacterial disease transmission.
11. What are the environmental impacts of construction due to growing urbanization and development?
Answer
Due to growing urbanization and development, large quantities of waste is generated due to construction work, some of which includes building materials used for insulation, broken nails, electrical wiring, switches, bulbs, wood, rubble etc. Many hazardous wastes such as lead, asbestos, paints etc. are also generated by construction units. All these lead to environmental pollution. Also there is the problem of disposing off these wastes safely without harming the environment.
12. What do you mean by e-waste?
Answer
E-waste or electronic waste refers to loosely discarded, surplus, obsolete, or broken electronic or electrical devices.
13. Give two examples of e-waste.
Answer
Discarded computers and broken cell phones
14. Name two biodegradable wastes from offices.
Answer
Used paper and old furniture
15. What does mining waste comprise of? What hazards do they pose to environment?
Answer
Mining waste includes waste generated during the extraction, beneficiation and processing of minerals. This comprises slimes, gangue, tailing piles and leach residues.
Hazards posed by mining include:
- Release of harmful gases such as methane.
- Elimination of existing vegetation and destruction of the genetic profile of soil.
- Continuous mining at a place can displace or destroy wildlife and habitat.
16. What do you mean by industrial wastes?
Answer
Waste that is produced by any industrial activity such as that from factories, mills and mines is called industrial waste.
17. Each question has four options. Choose the correct answer:
(i) Most harmful type of environmental pollutants are
(a) human organic wastes
(b) natural nutrients in excess
(c) waste animal feed
(d) non-biodegradable chemicals
Answer
(d) Non-biodegradable chemicals
(ii) Continuous sewage flow into a stream would lead to
(a) eutrophication
(b) algal bloom
(c) depletion of oxygen
(d) increase in temperature
(a) eutrophication
(b) algal bloom
(c) depletion of oxygen
(d) increase in temperature
Answer
(a) Eutrophication
(iii) Pollution can be checked through
(a) reducing discharge of waste
(b) increasing industrial development
(c) throwing wastes in open spaces
(d) all the above
Answer
(a) reducing discharge of waste
(b) increasing industrial development
(c) throwing wastes in open spaces
(d) all the above
Answer
(a) reducing discharge of waste
(iv) Domestic waste constitutes
(a) non-biodegradable pollution
(b) biodegradable pollution
(c) effluents
(d) air pollution
(a) non-biodegradable pollution
(b) biodegradable pollution
(c) effluents
(d) air pollution
Answer
(b) biodegradable pollution
(v) Which one is biological in sewage treatment?
(a) primary treatment
(b) secondary treatment
(c) tertiary treatment
(d) all the above
(a) primary treatment
(b) secondary treatment
(c) tertiary treatment
(d) all the above
Answer
(b) secondary treatment
(vi) Biodegradable pollutant is
(a) plastic
(b) asbestos
(c) sewage
(d) mercury
(a) plastic
(b) asbestos
(c) sewage
(d) mercury
Answer
(c) sewage
(vii) Which one is most toxic?
(a) Carbon
(b) CO
(c) CO2
(d) SO2
Answer
(a) Carbon
(b) CO
(c) CO2
(d) SO2
Answer
(b) CO
(viii) Fish die in water bodies polluted by sewage due to
(a) pathogens
(b) clogging of gills by silt
(c) reduction in oxygen
(d) foul smell
Answer
(a) pathogens
(b) clogging of gills by silt
(c) reduction in oxygen
(d) foul smell
Answer
(c) reduction in oxygen
(ix) Huge quantity of sewage is dumped in a river. The BOD will
(a) increase
(b) decrease
(c) slightly decrease
(d) remain uncharged
Answer
(a) increase
(b) decrease
(c) slightly decrease
(d) remain uncharged
Answer
(a) increase
(x) BOD is
(a) Biological Oxygen Deficit
(b) Biosphere Oxygen Demand
(c) Biological Oxygen Demand
(d) All the above
(a) Biological Oxygen Deficit
(b) Biosphere Oxygen Demand
(c) Biological Oxygen Demand
(d) All the above
Answer
(c) Biological Oxygen Demand
(c) Biological Oxygen Demand