13. Our Environment

*नोट: यह सेक्शन रिवीजन के लिए है। अपना ज्ञान परखने के लिए ऊपर दिए गए क्विज़ में भाग लें।

1. Substances that are broken down by biological processes are called:
   A) Non-biodegradable  |  B) Biodegradable  |  C) Plastic  |  D) None of these
2. An example of an abiotic component of an ecosystem is:
   A) Plants  |  B) Temperature, rain and soil  |  C) Animals  |  D) Microorganisms
3. Who are the Producers in a food chain?
   A) Lion  |  B) Green plants  |  C) Goat  |  D) Eagle
4. In which part of the atmosphere is the Ozone Layer found?
   A) Troposphere  |  B) Stratosphere  |  C) Mesosphere  |  D) Exosphere
5. What is the molecular formula of Ozone?
   A) O  |  B) O2  |  C) O3  |  D) H2O
6. Which rays from the sun cause skin cancer?
   A) Infrared rays  |  B) Ultraviolet (UV) rays  |  C) Visible light  |  D) X-rays
7. Names of any two biotic components are:
   A) Soil and air  |  B) Plants and animals  |  C) Water and light  |  D) Gold and silver
8. In which category are herbivorous animals placed?
   A) Producers  |  B) Primary Consumers  |  C) Secondary consumers  |  D) Decomposers
9. The chemical most responsible for damaging the ozone layer is:
   A) CO2  |  B) CFC (Chlorofluorocarbons)  |  C) N2  |  D) CH4
10. What percentage of energy goes to the next level in a food chain?
    A) 100%  |  B) 10%  |  C) 50%  |  D) 1%
11. What is the function of Decomposers?
    A) Making food  |  B) Breaking down complex organic substances into simple inorganic substances  |  C) Hunting  |  D) Releasing oxygen
12. The '3R' technique in waste management includes:
    A) Reduce, Reuse, Recycle  |  B) Read, Write, Run  |  C) Red, Blue, Green  |  D) None of these
13. An example of a man-made ecosystem is:
    A) Forest  |  B) Crop fields and gardens  |  C) Lake  |  D) River
14. Which is an Omnivore organism?
    A) Lion  |  B) Humans  |  C) Deer  |  D) Goat
15. What is the main source of energy in an ecosystem?
    A) Coal  |  B) Sunlight  |  C) Electricity  |  D) Food
16. Which is a biodegradable waste?
    A) Glass  |  B) Fruit peels and paper  |  C) Plastic bag  |  D) Aluminium foil
17. What are the various levels of a food chain called?
    A) Food web  |  B) Trophic levels  |  C) Pyramid  |  D) None of these
18. The ozone layer protects us from ultraviolet radiation of the sun, True or False?
    A) True  |  B) False  |  C) Can't say  |  D) None of these
19. CFC is mainly used in:
    A) Cooking  |  B) Refrigerators and fire extinguishers  |  C) Bicycles  |  D) Pens
20. What is the approximate amount of oxygen in the atmosphere?
    A) 78%  |  B) 21%  |  C) 0.03%  |  D) 1%
21. How is the flow of energy in trophic levels?
    A) Multidirectional  |  B) Unidirectional  |  C) Cyclic  |  D) None of these
22. What does Biological Magnification mean?
    A) Organisms getting larger  |  B) Increase in concentration of harmful chemicals at each trophic level  |  C) Increase in number  |  D) None of these
23. What is a Food Web?
    A) Spider web  |  B) A complex network of several food chains  |  C) Soil web  |  D) None of these
24. How much energy is lost from one trophic level to the next?
    A) 10%  |  B) 90%  |  C) 50%  |  D) 0%
25. Why are decomposers important for the ecosystem?
    A) They give oxygen  |  B) They ensure recycling of nutrients  |  C) They look beautiful  |  D) None of these
26. What percentage of total solar energy can green plants absorb?
    A) 10%  |  B) 1% (approx.)  |  C) 50%  |  D) 100%
27. What will happen if all deer are removed from a grassland?
    A) Grass will increase  |  B) Number of lions will decrease  |  C) Ecological balance will be disturbed  |  D) All of the above
28. How is an ozone molecule formed?
    A) Effect of UV rays on O2  |  B) From CO2  |  C) From N2  |  D) From H2O
29. Why do non-biodegradable substances persist in the environment?
    A) They are heavy  |  B) Enzymes of microorganisms cannot decompose them  |  C) They don't dissolve in water  |  D) None of these
30. What does the Top Carnivore in a food chain receive the most?
    A) Energy  |  B) Accumulation of chemicals (Bio-magnification)  |  C) Food  |  D) Oxygen
31. UNEA agreed to freeze CFC production at which level in 1987?
    A) 1950 level  |  B) 1986 level  |  C) Zero level  |  D) None of these
32. Which is the lowest level in an ecological pyramid?
    A) Herbivores  |  B) Producers  |  C) Carnivores  |  D) Humans
33. In the food chain 'Grass → Grasshopper → Frog → Snake → Eagle', who is at the third trophic level?
    A) Grasshopper  |  B) Frog  |  C) Snake  |  D) Grass
34. Why was the use of Kulhads suggested instead of disposable plastic cups?
    A) It's cheap  |  B) It's biodegradable and mixes with soil  |  C) It's beautiful  |  D) None of these
35. What is the cycling of elements in an ecosystem called?
    A) Chemical cycle  |  B) Biogeochemical cycle  |  C) Air cycle  |  D) None of these
36. The amount of energy in a food chain on going to the next level:
    A) Increases  |  B) Decreases  |  C) Remains same  |  D) Becomes zero
37. What is the biggest problem in Waste Disposal?
    A) Excess of non-biodegradable waste  |  B) Color of waste  |  C) Smell of waste  |  D) None of these
38. What is the unit to measure the thickness of the ozone layer?
    A) Meter  |  B) Dobson Unit  |  C) Gram  |  D) Liter
39. What are Algae in an ecosystem?
    A) Consumers  |  B) Producers  |  C) Decomposers  |  D) Parasites
40. Most helpful in preventing soil erosion is:
    A) Plastic  |  B) Vegetation  |  C) Buildings  |  D) None of these
41. Who proposed the '10 percent law' of energy?
    A) Darwin  |  B) Raymond Lindeman  |  C) Odum  |  D) Mendel
42. Bio-magnification has the worst effect on:
    A) Plants  |  B) Top organism of food chain (like humans)  |  C) Insects  |  D) Soil
43. Where was the Ozone Hole first observed?
    A) Over India  |  B) Over Antarctica  |  C) Sahara Desert  |  D) USA
44. From where do Secondary Consumers get energy?
    A) Directly from plants  |  B) From primary consumers (herbivores)  |  C) From the sun  |  D) From decomposers
45. What does 'Linkage' mean in an ecosystem?
    A) Interdependence of organisms  |  B) Growth of plants  |  C) Flow of water  |  D) None of these
46. How do pesticides (like DDT) enter the food chain?
    A) From air  |  B) Absorbed by plants from soil and water  |  C) By eating meat directly  |  D) None of these
47. How many atoms of oxygen are in one molecule of ozone?
    A) 2  |  B) 3  |  C) 4  |  D) 1
48. What is the main human cause of ecological imbalance?
    A) Afforestation  |  B) Deforestation and pollution  |  C) Cleaning  |  D) Farming
49. UV radiation at higher levels of atmosphere splits oxygen molecules (O2) into:
    A) CO2  |  B) Free oxygen (O) atoms  |  C) Ozone  |  D) Nitrogen
50. Why can Heterotrophs not make their own food?
    A) They don't have legs  |  B) They lack chlorophyll  |  C) They don't sit in the sun  |  D) None of these
51. In a food chain, which trophic level does a 'Tiger' represent?
    A) First  |  B) Top Trophic level  |  C) Second  |  D) Third
52. What is the main difference between composting and vermicomposting?
    A) No difference  |  B) Vermicomposting uses earthworms  |  C) Composting has only plastic  |  D) None of these
53. Why is the length of a food chain generally limited to 3 or 4 levels?
    A) Organisms are few  |  B) Amount of energy becomes very low reaching higher levels  |  C) Space is less  |  D) None of these
54. Montreal Protocol is related to:
    A) Global warming  |  B) Ozone layer protection (ban on CFC)  |  C) Forest conservation  |  D) Water pollution
55. Decomposers convert complex substances into:
    A) Poisonous substances  |  B) Inorganic nutrients  |  C) Plastic  |  D) Smoke
56. Only 1% of solar energy is converted into food energy by green plants, where does the rest go?
    A) Into soil  |  B) Dissipated as heat into environment  |  C) Plants eat it  |  D) None of these
57. What do all organisms in an area and abiotic factors of the environment together form?
    A) Community  |  B) Ecosystem  |  C) Population  |  D) Sphere
58. Can the flow of energy in a food chain ever be in reverse direction (like lion to grass)?
    A) Yes  |  B) No (Never)  |  C) Only in winter  |  D) Can't say
59. What is the effect on plants on being exposed to ultraviolet radiation?
    A) Growth becomes fast  |  B) Burning of leaves and decrease in photosynthesis  |  C) They turn blue  |  D) No effect
60. When is World Environment Day celebrated?
    A) 1 January  |  B) 5 June  |  C) 15 August  |  D) 2 October