10TH/Bio/7/MCQs

Man and His Environment 


Easy Level (30%)

1. Which of the following best defines the environment?  

   - a) The natural world including only plants and animals  

   - b) All living things and non-living things surrounding an organism  

   - c) The activities done by humans  

   - d) Ecosystems and the atmosphere only  


2. What is ecology? 

   - a) The study of human population growth  

   - b) The study of relationships between organisms and their environment  

   - c) The study of human impact on earth  

   - d) The study of natural resources  


3. In an ecosystem, plants are generally known as: 

   - a) Consumers  

   - b) Producers  

   - c) Decomposers  

   - d) Parasites  


4. Which term describes the variety of life on Earth?  

   - a) Ecosystem  

   - b) Population  

   - c) Biodiversity  

   - d) Habitat  


5. What does a food chain represent?  

   - a) The habitat of organisms  

   - b) The flow of energy in an ecosystem  

   - c) The competition between species  

   - d) The structure of a community  


6. Which of the following is an abiotic component of an ecosystem?  

   - a) Plants  

   - b) Animals  

   - c) Sunlight  

   - d) Bacteria  


7. What is sustainable development?  

   - a) Use of resources without harming future generations  

   - b) Increasing the industrial footprint  

   - c) Rapid economic development  

   - d) Limited use of resources  


8. Which cycle involves the exchange of water in nature?  

   - a) Nitrogen cycle  

   - b) Water cycle  

   - c) Carbon cycle  

   - d) Phosphorus cycle  


9. Which of these is a primary consumer?  

   - a) Plants  

   - b) Deer  

   - c) Wolves  

   - d) Fungi  


10. What is the main source of energy for most ecosystems?  

    - a) The ocean  

    - b) The sun  

    - c) Volcanoes  

    - d) Soil  


Moderate Level (40%)

11. The level of ecological organization that consists of different populations is called a:  

    - a) Biosphere  

    - b) Population  

    - c) Community  

    - d) Ecosystem  


12. Which process is primarily responsible for adding oxygen to the atmosphere?  

    - a) Photosynthesis  

    - b) Respiration  

    - c) Decomposition  

    - d) Nitrogen fixation  


13. Which of the following is an example of mutualism?  

    - a) A lion hunting a deer  

    - b) A tick feeding on a dog  

    - c) Bees pollinating flowers  

    - d) Fungi decomposing dead organisms  


14. In which ecological pyramid is the total biomass measured at each trophic level?  

    - a) Pyramid of numbers  

    - b) Pyramid of energy  

    - c) Pyramid of biomass  

    - d) Pyramid of species  


15. Which of the following statements is true about decomposers?  

    - a) They make their own food  

    - b) They help recycle nutrients back into the ecosystem  

    - c) They produce energy through photosynthesis  

    - d) They do not depend on other organisms  


16. Which component is considered a biotic factor in an ecosystem?  

    - a) Sunlight  

    - b) Water  

    - c) Fungi  

    - d) Minerals  


17. What is the role of autotrophs in an ecosystem?  

    - a) To consume other organisms  

    - b) To recycle dead material  

    - c) To produce energy from sunlight  

    - d) To act as predators  


18. Which biogeochemical cycle involves the conversion of atmospheric nitrogen to a usable form for plants?  

    - a) Carbon cycle  

    - b) Water cycle  

    - c) Nitrogen cycle  

    - d) Phosphorus cycle  


19. Which of the following describes the nitrogen cycle?  

    - a) Transfer of carbon between plants and animals  

    - b) Circulation of nitrogen between organisms and the environment  

    - c) Movement of water through ecosystems  

    - d) Production of oxygen by plants  


20. What is a niche in an ecosystem?  

    - a) A physical area where an organism lives  

    - b) The role or function of an organism within its environment  

    - c) A group of similar organisms  

    - d) The total biomass of an ecosystem  


21. Which type of organism can convert sunlight into chemical energy?  

    - a) Heterotroph  

    - b) Autotroph  

    - c) Decomposer  

    - d) Scavenger  


22. Which of the following is an example of an ecosystem?

    - a) Only trees  

    - b) Animals and plants  

    - c) Forest with all its organisms and environment  

    - d) Plants only  


23. How does deforestation affect biodiversity?  

    - a) It increases biodiversity  

    - b) It reduces biodiversity  

    - c) It has no effect on biodiversity  

    - d) It only affects abiotic factors  


24. Which of the following is an example of symbiosis?  

    - a) Fish swimming in a school  

    - b) Birds hunting insects together  

    - c) A clownfish living with a sea anemone  

    - d) A deer grazing on grass  


25. What is the main reason for the buildup of greenhouse gases?  

    - a) Respiration by plants  

    - b) Burning of fossil fuels  

    - c) Photosynthesis  

    - d) Water cycle  


26. What is a habitat?  

    - a) The role of an organism  

    - b) The place where an organism lives  

    - c) An entire ecosystem  

    - d) A specific type of food  


27. Which of the following pollutants is a greenhouse gas?  

    - a) Oxygen  

    - b) Nitrogen  

    - c) Carbon dioxide  

    - d) Neon  


28. Which of the following statements is true about energy flow in ecosystems?

    - a) Energy flows in cycles  

    - b) Energy flows in one direction  

    - c) Energy can flow in any direction  

    - d) Energy remains constant at each level  


29. The practice of conserving resources through reduction, reuse, and recycling is known as:  

    - a) Waste disposal  

    - b) The 3 R's  

    - c) Biogeochemical cycling  

    - d) Deforestation  


30. Which of the following describes the phosphorus cycle?  

    - a) Involves the movement of water  

    - b) Involves the weathering of rocks  

    - c) Transfers nitrogen between organisms  

    - d) Releases oxygen into the atmosphere  


Tough Level (30%)

31. What limits the number of trophic levels in an ecosystem?  

    - a) Abundance of sunlight  

    - b) Energy loss at each trophic level  

    - c) Diversity of species  

    - d) Water availability  


32. Which of the following is a likely consequence of introducing an invasive species into an ecosystem?  

    - a) Increased native biodiversity  

    - b) Stabilization of the ecosystem  

    - c) Disruption of existing food webs  

    - d) More food for native predators  


33. Why is the carbon cycle critical for maintaining life?  

    - a) It balances the amount of water on Earth  

    - b) It provides energy to decomposers  

    - c) It regulates the levels of carbon dioxide and oxygen  

    - d) It circulates minerals in the soil  


34. Which ecological pyramid can never be inverted?  

    - a) Pyramid of numbers  

    - b) Pyramid of energy  

    - c) Pyramid of biomass  

    - d) Pyramid of species  


35. Which of the following best describes biomagnification?  

    - a) The increase in population size of predators  

    - b) The concentration of toxins at higher trophic levels  

    - c) The process of photosynthesis in producers  

    - d) The reproduction of organisms in ecosystems  


36. What is the primary cause of acid rain?

    - a) Carbon dioxide emissions  

    - b) Sulfur and nitrogen oxides in the atmosphere  

    - c) Ozone layer depletion  

    - d) Methane gas emissions  


37. **How does cellular respiration contribute to the carbon cycle?**  

    - a) By releasing oxygen into the atmosphere  

    - b) By using sunlight to produce glucose  

    - c) By converting glucose to carbon dioxide  

    - d) By adding carbon to fossil fuels  


38. What does a pyramid of energy illustrate?  

    - a) The total number of organisms  

    - b) The total biomass at each level  

    - c) The flow of energy from producers to top consumers  

    - d) The concentration of nutrients at


 each level  


39. In a food web, how is energy primarily lost between trophic levels? 

    - a) Through digestion  

    - b) As heat  

    - c) Through respiration only  

    - d) As stored fat  


40. Which of the following biomes has the highest biodiversity?

    - a) Tundra  

    - b) Desert  

    - c) Tropical rainforest  

    - d) Grassland  


Answers

1. b  

2. b  

3. b  

4. c  

5. b  

6. c  

7. a  

8. b  

9. b  

10. b  

11. c  

12. a  

13. c  

14. c  

15. b  

16. c  

17. c  

18. c  

19. b  

20. b  

21. b  

22. c  

23. b  

24. c  

25. b  

26. b  

27. c  

28. b  

29. b  

30. b  

31. b  

32. c  

33. c  

34. b  

35. b  

36. b  

37. c  

38. c  

39. b  

40. c