MCQs Science Olympiad for Class 4, Chapter - Environment and Ecosystem

 

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1-10: Environment Basics

1. What is the main source of energy for life on Earth?
   a) Water
   b) Sun
   c) Wind
   d) Soil
   Answer: b) Sun

2. Which of the following is a biotic component of the environment?
   a) Rock
   b) River
   c) Tree
   d) Air
   Answer: c) Tree

3. What do plants release during photosynthesis?
   a) Carbon dioxide
   b) Oxygen
   c) Nitrogen
   d) Sulfur
   Answer: b) Oxygen

4. What is the process of removing waste and pollution from the environment called?
   a) Decomposition
   b) Recycling
   c) Pollution
   d) Respiration
   Answer: b) Recycling

5. Which gas is most abundant in Earth's atmosphere?
   a) Oxygen
   b) Carbon dioxide
   c) Nitrogen
   d) Hydrogen
   Answer: c) Nitrogen

6. What are non-renewable resources?
   a) Resources that cannot be used
   b) Resources that cannot be replenished
   c) Resources that are infinite
   d) None of these
   Answer: b) Resources that cannot be replenished

7. Which is an example of a renewable resource?
   a) Coal
   b) Petroleum
   c) Solar energy
   d) Natural gas
   Answer: c) Solar energy

8. Which of these animals is a herbivore?
   a) Tiger
   b) Rabbit
   c) Eagle
   d) Snake
   Answer: b) Rabbit

9. What is deforestation?
   a) Planting trees
   b) Cutting down forests
   c) Protecting wildlife
   d) Cleaning rivers
   Answer: b) Cutting down forests

10. Which type of pollution is caused by vehicles and factories?
    a) Noise pollution
    b) Air pollution
    c) Water pollution
    d) Land pollution
    Answer: b) Air pollution

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11-20: Ecosystem Components

11. What is an ecosystem?
    a) A large city
    b) All the living and non-living things in an area
    c) A group of plants
    d) Only animals in an area
    Answer: b) All the living and non-living things in an area

12. What are decomposers?
    a) Animals that eat plants
    b) Organisms that break down dead matter
    c) Large predators
    d) Producers of food
    Answer: b) Organisms that break down dead matter

13. Which of the following is a natural ecosystem?
    a) Aquarium
    b) Forest
    c) Zoo
    d) Garden
    Answer: b) Forest

14. Plants are known as:
    a) Consumers
    b) Producers
    c) Decomposers
    d) Predators
    Answer: b) Producers

15. Which of these is not a consumer?
    a) Lion
    b) Cow
    c) Deer
    d) Mango tree
    Answer: d) Mango tree

16. What do herbivores eat?
    a) Meat
    b) Plants
    c) Fish
    d) Insects
    Answer: b) Plants

17. Which of these is a carnivore?
    a) Elephant
    b) Tiger
    c) Cow
    d) Deer
    Answer: b) Tiger

18. What is a food chain?
    a) A chain of stores
    b) A sequence of organisms feeding on one another
    c) A group of forests
    d) None of these
    Answer: b) A sequence of organisms feeding on one another

19. Which of these animals is an omnivore?
    a) Dog
    b) Goat
    c) Cat
    d) Bear
    Answer: d) Bear

20. What do scavengers feed on?
    a) Fresh plants
    b) Dead animals
    c) Live fish
    d) None of these
    Answer: b) Dead animals

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21-30: Environmental Protection

21. Which of these helps reduce air pollution?
    a) Planting more trees
    b) Using more plastic
    c) Burning more fuel
    d) Cutting trees
    Answer: a) Planting more trees

22. What is the term for reusing materials instead of throwing them away?
    a) Pollution
    b) Recycling
    c) Burning
    d) Mining
    Answer: b) Recycling

23. What can help save water?
    a) Using sprinklers all day
    b) Fixing leaky taps
    c) Overwatering plants
    d) Washing cars daily
    Answer: b) Fixing leaky taps

24. Which of the following is biodegradable?
    a) Plastic bottle
    b) Banana peel
    c) Aluminum foil
    d) Glass jar
    Answer: b) Banana peel

25. What should be avoided to reduce plastic pollution?
    a) Using reusable bags
    b) Burning dry leaves
    c) Using paper bags
    d) Using plastic bags
    Answer: d) Using plastic bags

26. Which of these is a good way to protect wildlife?
    a) Hunting animals
    b) Destroying forests
    c) Setting up wildlife sanctuaries
    d) Polluting rivers
    Answer: c) Setting up wildlife sanctuaries

27. What is an example of water pollution?
    a) Throwing garbage into rivers
    b) Drinking clean water
    c) Taking a bath
    d) Swimming in a pool
    Answer: a) Throwing garbage into rivers

28. What type of waste is best suited for composting?
    a) Plastic bottles
    b) Fruit peels
    c) Glass jars
    d) Metal cans
    Answer: b) Fruit peels

29. How can we save electricity?
    a) Keeping lights on all day
    b) Turning off fans when not in use
    c) Using old appliances
    d) None of these
    Answer: b) Turning off fans when not in use

30. Why is it important to conserve forests?
    a) For wildlife and oxygen
    b) To increase factories
    c) To cut more trees
    d) To clear land for roads
    Answer: a) For wildlife and oxygen

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31-60: Miscellaneous

31. What is the habitat of a polar bear?
    a) Desert
    b) Ocean
    c) Arctic region
    d) Forest
    Answer: c) Arctic region

32. Which of the following animals lives in the desert?
    a) Camel
    b) Shark
    c) Penguin
    d) Frog
    Answer: a) Camel

31. What is the habitat of frogs?
    a) Desert
    b) Grassland
    c) Wetlands
    d) Polar region
    Answer: c) Wetlands

32. Which of the following is an adaptation in desert animals?
    a) Thick fur
    b) Long eyelashes
    c) Webbed feet
    d) Bright feathers
    Answer: b) Long eyelashes

33. What helps fish survive in water?
    a) Gills
    b) Legs
    c) Lungs
    d) Wings
    Answer: a) Gills

34. Which of these animals lives in the polar region?
    a) Elephant
    b) Kangaroo
    c) Seal
    d) Snake
    Answer: c) Seal

35. What is the role of a cactus in the desert ecosystem?
    a) Provides food and stores water
    b) Increases temperature
    c) Drains water from the soil
    d) None of these
    Answer: a) Provides food and stores water

36. How do trees in rainforests adapt to heavy rainfall?
    a) By having small roots
    b) By growing waxy leaves
    c) By not growing tall
    d) By growing spines
    Answer: b) By growing waxy leaves

37. What type of ecosystem is the ocean?
    a) Terrestrial
    b) Aquatic
    c) Desert
    d) Forest
    Answer: b) Aquatic

38. Which plant is found in the aquatic ecosystem?
    a) Cactus
    b) Pine
    c) Water lily
    d) Neem
    Answer: c) Water lily

39. What is the natural habitat of a lion?
    a) Arctic
    b) Grassland
    c) Ocean
    d) Wetland
    Answer: b) Grassland

40. Which of the following is a nocturnal animal?
    a) Crow
    b) Bat
    c) Deer
    d) Peacock
    Answer: b) Bat

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41-50: Pollution and Conservation

41. What is noise pollution caused by?
    a) Too much garbage
    b) Loud sounds
    c) Smoke from factories
    d) Deforestation
    Answer: b) Loud sounds

42. Which of these is the best way to reduce pollution?
    a) Using bicycles instead of cars
    b) Throwing garbage on roads
    c) Burning plastic
    d) Cutting down trees
    Answer: a) Using bicycles instead of cars

43. Which type of pollution harms marine life?
    a) Water pollution
    b) Noise pollution
    c) Air pollution
    d) Soil pollution
    Answer: a) Water pollution

44. What is the best way to dispose of kitchen waste?
    a) Throwing it in rivers
    b) Burning it
    c) Composting
    d) Burying plastics with it
    Answer: c) Composting

45. Which of these contributes to air pollution?
    a) Car emissions
    b) Planting trees
    c) Cleaning rivers
    d) Using solar energy
    Answer: a) Car emissions

46. Which of these can help conserve wildlife?
    a) Poaching
    b) Building wildlife reserves
    c) Cutting forests
    d) Polluting rivers
    Answer: b) Building wildlife reserves

47. Why should we recycle paper?
    a) To save water
    b) To save trees
    c) To save energy
    d) All of the above
    Answer: d) All of the above

48. What is the effect of soil pollution?
    a) Increases soil fertility
    b) Reduces crop growth
    c) Cleans the soil
    d) Improves water quality
    Answer: b) Reduces crop growth

49. Which of the following is not biodegradable?
    a) Plastic
    b) Paper
    c) Food waste
    d) Cotton
    Answer: a) Plastic

50. What is afforestation?
    a) Cutting down trees
    b) Planting new trees
    c) Removing plants
    d) Building houses in forests
    Answer: b) Planting new trees

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51-60: Advanced Topics and General Questions

51. What is the topmost layer of a rainforest called?
    a) Forest floor
    b) Understory
    c) Canopy
    d) Emergent
    Answer: d) Emergent

52. Which of these is an abiotic component of an ecosystem?
    a) Insects
    b) Plants
    c) Sunlight
    d) Birds
    Answer: c) Sunlight

53. What does the food web represent?
    a) A single food chain
    b) All interlinked food chains in an ecosystem
    c) A chain of producers only
    d) None of these
    Answer: b) All interlinked food chains in an ecosystem

54. Which process in plants helps maintain the balance of oxygen in the air?
    a) Transpiration
    b) Photosynthesis
    c) Respiration
    d) Pollination
    Answer: b) Photosynthesis

55. Which of these is not a part of the water cycle?
    a) Evaporation
    b) Condensation
    c) Precipitation
    d) Erosion
    Answer: d) Erosion

56. Which gas is absorbed by plants during photosynthesis?
    a) Nitrogen
    b) Carbon dioxide
    c) Oxygen
    d) Methane
    Answer: b) Carbon dioxide

57. What is the primary role of roots in plants?
    a) To produce flowers
    b) To absorb water and nutrients
    c) To make food
    d) To protect the leaves
    Answer: b) To absorb water and nutrients

58. Which human activity leads to soil erosion?
    a) Building dams
    b) Overgrazing by animals
    c) Planting trees
    d) Using compost
    Answer: b) Overgrazing by animals

59. What is the purpose of national parks?
    a) To build houses
    b) To protect wildlife and forests
    c) To grow crops
    d) To mine minerals
    Answer: b) To protect wildlife and forests

60. Why are wetlands important?
    a) They are waste areas
    b) They support a wide variety of life forms
    c) They destroy crops
    d) They block rivers
    Answer: b) They support a wide variety of life forms