1. Select the correct statement from the following.
(a) Biogas is produced by the activity of aerobic bacteria on animal waste.
(b) Methanobacterium is an aerobic bacterium found in rumen of cattle.
(c) Biogas, commonly called gobar gas, is pure methane.
(d) Activated sludge-sediment in settlement tanks of sewage treatment plant is a rich source of aerobic bacteria.
2. When domestic sewage mixes with river water
(a) small animals like rats will die after drinking river water
(b) the increased microbial activity releases micronutrients such as iron
(c) the increased microbial activity uses up dissolved oxygen
(d) the river water is still suitable for drinking as impurities are only about 0.1%.
3. Which of the following diseases is related to cadmium pollution?
(a) Minamata (b) Pneumoconiosis
(c) Anaemia (d) Itai-itai
4. Electrostatic precipitators are extensively employed to control
(a) water pollution
(b) air pollution
(c) radioactive pollution
(d) none of these.
5. Which of the following is a secondary pollutant?
(a) PAN (b) Particulate matter
(c) Hydrocarbons (d) Chlorofluorocarbons
6. Gases mainly responsible for the acid rain are (a) SO2 , NO2 (b) CO, CO2
(c) CH4, O3 (d) O2, NH3.
7. Calcium metabolism in birds gets disturbed due to the effect of
(a) mercury (b) cadmium
(c) DDT (d) lead.
8. Match the items of Column I with Column II and select the correct option.
9. Measuring Biochemical Oxygen Demand (BOD) is a method used for
(a) estimating the amount of organic matter in sewage water
(b) working out the efficiency of oil driven automobile engines
(c) measuring the activity of Saccharomyces cerevisiae in producing curd on a commercial scale
(d) working out the efficiency of RBCs about their capacity to carry oxygen.
10. Carbon dioxide is called as “greenhouse” gas, because
(a) it is involved in photosynthesis
(b) it emits light
(c) it traps infrared radiations
(d) it traps ultraviolet radiations.
11. Global warming can be controlled by
(a) increasing deforestation, slowing down the growth of human population.
(b) increasing increasing deforestation, reducing efficiency of energy usage
(c) reducing deforestation, cutting down use of fossil fuel.
(d) reducing reforestation, increasing the use of fossil fuel.
12. Which of the following is not correct with regard to the harmful effects of particulate matter of the size 2.5 micrometers or less?
(a) It can cause respiratory problems.
(b) It can directly enter into our circulatory system.
(c) It can cause inflammation and damage to the lungs.
(d) It can be inhaled into the lungs.
13. Which of the following gases is produced in paddy field?
(a) CH4 (b) H2S (c) CO2 (d) SO2
14. ‘Floc’ is ____
(a) a mesh-like structure formed by the association of bacteria and fungal filaments in sewage treatment
(b) the primary sludge produced in sewage treatment
(c) the effluent in primary treatment tank obtained during sewage treatment
(d) a type of biofortified food.
15. The prime contaminants in lakes eutrophied by sewage and agricultural wastes are
(a) sulphates and phosphates
(b) nitrates and sulphates
(c) nitrates and phosphates
(d) nitrates and carbonates.
18. The given graph shows the effect of sewage discharge in a water body and recovery of same after some distance.
(a) What do curves ‘I’ and ‘II’ represent in the given graph?
(b) Explain the processes occurring at point X in the given graph.
19. Refer the given flow chart and answer the following questions.
(a) Identify (1), (2), (3), (4) and (5) in the given flow chart.
(b) Fill in the blanks using these numbers.
(i) Normally, _______ combines with haemoglobin producing carboxyhaemoglobin in case of very low oxygen conditions.
(ii) _______ is a condition in which oxygen is prevented from reaching the tissues.
(iii) Helsinki Declaration was held in May 1989 to phase out ______.
(iv) CFCs release active chlorine which leads to ______.
(v) In animals _______, bring about abnormal calcification of bones and teeth.