Chapter 17 : OUR ENVIRONMENT

Choose Appropriate Alternative

1. Which of the following is an example of biodegradable waste?
   

   [A] Vegetables [B] Glass [C] Plastic [D] Metal

2. Which of the following is an example of non-biodegradable waste?
   

   [A] Fruits [B] Vegetables [C] Paper [D] Polythene

3. Ecosystem is an interactive system made up of...
   

   [A] organisms and their physical surrounding 
   [B] producers and consumers 
   [C] producers and their physical surroundings 
   [D] consumers and their physical surroundings

4. The structural and functional unit of the environment is known as...
   

   [A] food chain [B] food web [C] ecosystem [D] none of them

5. First order consumers are...
   

   [A] carnivores [B] herbivores [C] decomposers [D] omnivores

6. Omnivorous organisms consume...
   

   [A] only plants              [B] only animals 
   [C] plants and animals both [D] microorganisms

7. Edaphic factors are included in...
   

   [A] abiotic components [B] biotic components 
   [C] producers         [D] consumers

8. How many molecules of ozone can be decomposed by one atom of chlorine?
   

   [A] 10000 [B] 100000 [C] 1000000 [D] 1000

9. The most important compound which accounts for 80% of total depletion of ozone layer is...
   

   [A] chloride ion [B] sulphur ion 
   [C] chloroflurocarbons [D] magnesium ion

10. Which of the following is not an abiotic component?
    

    [A] Micro-organisms [B] Temperature [C] Water [D] Soil

11. Which of the following is an edaphic component?
    

    [A] Temperature [B] Humidity [C] Light [D] Soil structure

12. The flow of energy in an ecosystem is...
    

    [A] reversible [B] cyclic [C] unidirectional [D] erratic

13. Ozone layer is located in _____ of atmosphere.
    

    [A] troposphere [B] stratosphere [C] ionosphere [D] mesosphere

14. Which rays strike in large amount on earth due to depletion of ozone layer?
    

    [A] Ultraviolet [B] Infra-red [C] Visible [D] Microwaves

15. All organisms and their physical surroundings with which they interact are collectively called...
    

    [A] environment [B] atmosphere [C] hydrosphere [D] lithosphere

16. In which two major forms can the wastes be classified?
    

    [A] Gas and fluids [B] Gas and liquids [C] Fluids and solids [D] Solids and liquids

17. The waste materials which can be decomposed by biological processes are called...
    

    [A] biodegradable [B] non-biodegradable [C] bio-nondegradable [D] organic substances

18. The interacting system formed by association of biotic community and physical environment is called...
    

    [A] ecosystem [B] biome [C] biosphere [D] food web

19. Which biotic components form the first trophic level?
    

    [A] Producers [B] Herbivores [C] Carnivores [D] Decomposers

20. On the basis of nutrition, producers are...
    

    [A] heterotrophic [B] parasitic [C] autotrophic [D] saprophytic

21. What is the mode of nutrition in consumers?
    

    [A] Autotrophic [B] Heterotrophic [C] Holozoic [D] Parasitic

22. The organisms which utilize plants and animals as food are called...
    

    [A] herbivores [B] carnivores [C] omnivores [D] saprophytes

23. The organisms which convert complex organic components of dead bodies into simple organic molecules are called...
    

    [A] micro-organisms [B] decomposers [C] transformers [D] converters

24. The organisms which convert simple organic compounds into simple inorganic compounds are called...
    

    [A] micro-organisms [B] decomposers [C] transformers [D] converters

25. Into which two categories can the abiotic components of an ecosystem be divided?
    

    [A] Climatic and edaphic [B] Aquatic and edaphic 
    [C] Climatic and aquatic [D] Terrestrial and aquatic

26. The first link of a grazing food chain is formed by...
    

    [A] producers [B] consumers [C] decomposers [D] transformers

27. A detritus food chain starts with...
    

    [A] producers [B] herbivores [C] decomposers [D] carnivores

28. The network formed by interlinking food chains is called...
    

    [A] food link [B] food web [C] ecosystem [D] trophic system

29. Which radiations are prevented by ozone layer from reaching the Earth?
    

    [A] X-rays [B] Infra-red [C] Ultraviolet [D] Micro-waves

30. Which reaction plays an important role in breaking of oxygen molecule into oxygen atoms before ozone formation in upper atmosphere?
    

    [A] Photosynthesis [B] Photolysis [C] Photo-emission [D] Photoformation

31. What is the wavelength of ultraviolet rays?
    

    [A] 310-200 A° [B] 310-200 nm [C] 310-525 A° [D] 310-525 nm

32. The depletion of ozone layer was first observed in ______ region.
    

    [A] tropical [B] sub-tropical [C] North polar [D] South polar

33. The CFC used in refrigerators and air-conditioners is...
    

    [A] radon [B] freon [C] chloron [D] zedon 

ANSWERS

(1) A (2) D (3) A (4) C (5) B (6) C (7) A (8) B (9) C (10) A (11) D (12) C (13) B (14) A (15) A (16) D (17) A (18) A (19) A (20) C (21) B (22) C (23) B (24) C (25) A (26) A (27) C (28) B (29) C (30) B (31) B (32) D (33) B (34) (35) (36) (37) (38) (39) (40)