1. What is the primary source of energy in an ecosystem?
a) Sunlight
b) Water
c) Wind
d) Soil
Answer: a) Sunlight
2. Which of the following best describes the 10% Law of Energy Transfer?
a) 90% of energy is transferred to the next trophic level
b) 10% of energy is transferred to the next trophic level
c) All energy is transferred to the next trophic level
d) 50% of energy is transferred to the next trophic level
Answer: b) 10% of energy is transferred to the next trophic level
3. In a food chain, where does most of the energy go?
a) Stored in producers
b) Lost as heat
c) Stored in consumers
d) Stored in decomposers
Answer: b) Lost as heat
4. Which of the following is a producer in an ecosystem?
a) Snake
b) Deer
c) Grass
d) Lion
Answer: c) Grass
5. The energy lost between trophic levels is primarily in the form of:
a) Light energy
b) Heat energy
c) Chemical energy
d) Electrical energy
Answer: b) Heat energy
6. Which of the following organisms is classified as a primary consumer?
a) Lion
b) Grasshopper
c) Eagle
d) Wolf
Answer: b) Grasshopper
7. In an ecosystem, which of the following has the highest energy content?
a) Tertiary consumers
b) Primary consumers
c) Secondary consumers
d) Producers
Answer: d) Producers
8. Which of the following best explains why energy decreases at higher trophic levels?
a) Energy is consumed by herbivores
b) Energy is stored in plants
c) Energy is lost as heat during metabolism
d) Energy is transferred to the soil
Answer: c) Energy is lost as heat during metabolism
9. In an energy pyramid, the size of each trophic level is:
a) Equal
b) Larger as you go up
c) Smaller as you go up
d) Unchanged
Answer: c) Smaller as you go up
10. Which of the following statements about the 10% rule is true?
a) 100% of energy is transferred to the next level
b) Only 10% of energy is available to the next trophic level
c) Energy is equally distributed among trophic levels
d) Producers use all energy for growth
Answer: b) Only 10% of energy is available to the next trophic level
11. Which of the following groups is considered the secondary consumers in an ecosystem?
a) Deer
b) Grass
c) Birds eating insects
d) Bacteria
Answer: c) Birds eating insects
12. How does energy flow in an ecosystem?
a) In a linear fashion
b) In a circular fashion
c) From bottom to top
d) From top to bottom
Answer: c) From bottom to top
13. Decomposers in an ecosystem:
a) Convert sunlight into energy
b) Consume primary producers
c) Break down organic matter and recycle nutrients
d) Feed on secondary consumers
Answer: c) Break down organic matter and recycle nutrients
14. What is the role of consumers in an ecosystem?
a) To produce energy
b) To break down waste materials
c) To transfer energy from producers to higher trophic levels
d) To recycle nutrients
Answer: c) To transfer energy from producers to higher trophic levels
15. Which of the following is the correct energy flow order in a food chain?
a) Primary consumers → Producers → Secondary consumers
b) Producers → Primary consumers → Secondary consumers
c) Secondary consumers → Producers → Primary consumers
d) Producers → Secondary consumers → Primary consumers
Answer: b) Producers → Primary consumers → Secondary consumers
16. The energy available to an apex predator is:
a) 100% of the energy in the ecosystem
b) Less than that available to producers
c) More than that available to producers
d) Equal to the energy available to producers
Answer: b) Less than that available to producers
17. What happens to the energy lost at each trophic level?
a) It is stored in the plants
b) It is used for growth
c) It is converted to light
d) It is lost as heat
Answer: d) It is lost as heat
18. The primary source of energy for most ecosystems is:
a) Heat from Earth’s core
b) Sunlight
c) Wind
d) Water
Answer: b) Sunlight
19. In the energy flow, which of the following organisms would have the least amount of energy available?
a) Primary consumers
b) Secondary consumers
c) Tertiary consumers
d) Producers
Answer: c) Tertiary consumers
20. Which of the following best describes an energy pyramid?
a) It shows the amount of energy at each trophic level
b) It represents the distribution of biomass across species
c) It demonstrates how water flows in ecosystems
d) It shows the flow of nutrients
Answer: a) It shows the amount of energy at each trophic level
21. The 10% energy transfer rule in ecosystems applies to:
a) Only plant-based food chains
b) The movement of water through ecosystems
c) The movement of energy from one trophic level to another
d) The movement of nutrients between soil and plants
Answer: c) The movement of energy from one trophic level to another
22. Which of the following is a primary producer in an ecosystem?
a) Deer
b) Algae
c) Hawk
d) Snake
Answer: b) Algae
23. Which of the following is the correct sequence of energy flow in an ecosystem?
a) Secondary consumers → Primary consumers → Producers
b) Producers → Secondary consumers → Primary consumers
c) Producers → Primary consumers → Secondary consumers
d) Secondary consumers → Producers → Primary consumers
Answer: c) Producers → Primary consumers → Secondary consumers
24. Which trophic level has the least amount of available energy?
a) Primary producers
b) Primary consumers
c) Secondary consumers
d) Tertiary consumers
Answer: d) Tertiary consumers
25. The energy available to higher trophic levels is significantly reduced because:
a) Organisms do not eat all available food
b) Energy is lost as heat during metabolic processes
c) Predators use up most of the energy
d) Energy is stored in dead matter
Answer: b) Energy is lost as heat during metabolic processes
26. In an energy pyramid, which trophic level is typically the largest?
a) Secondary consumers
b) Tertiary consumers
c) Producers
d) Decomposers
Answer: c) Producers
27. Which of the following statements is true regarding energy transfer in ecosystems?
a) Energy is transferred efficiently between trophic levels
b) All energy is transferred without loss
c) Energy is lost as heat at each trophic level
d) Energy transfer is only effective in the absence of decomposers
Answer: c) Energy is lost as heat at each trophic level
28. Which of the following is NOT a factor that affects energy transfer efficiency?
a) Amount of energy lost as heat
b) The diet of consumers
c) The availability of sunlight
d) The type of soil in the ecosystem
Answer: d) The type of soil in the ecosystem
29. Why is the energy available to tertiary consumers so low?
a) Energy is stored in soil
b) Energy is consumed by primary producers
c) Energy decreases at each trophic level
d) Energy is absorbed by decomposers
Answer: c) Energy decreases at each trophic level
30. The 10% rule of energy transfer suggests that:
a) Only 10% of energy in producers is available to consumers
b) 10% of energy in consumers is transferred to the environment
c) 90% of energy is transferred to the next trophic level
d) 10% of energy is lost during decomposition
Answer: a) Only 10% of energy in producers is available to consumers
These 30 MCQs offer a comprehensive overview of the topic “Energy Flow in Ecosystems: 10% Law of Energy Transfer,” covering the key concepts of energy flow, the 10% law, trophic levels, and their relevance in ecological studies.
