100 multiple-choice questions with answers on
ecosystems:
1. What is an ecosystem?
a) A single organism
b) A group of unrelated species
c) A community of organisms and their physical environment
d) A collection of rocks and minerals
Answer: c) A community of organisms and their physical
environment
2. Which of the following is a biotic component of an ecosystem?
a) Soil
b) Temperature
) Trees
d) Sunlight
Answer: c) Trees
3. Which gas is essential for photosynthesis in plants?
a) Oxygen
b) Nitrogen
c) Carbon dioxide
d) Hydrogen
Answer: c) Carbon dioxide
4. What is the primary source of energy in most ecosystems?
a) Wind
b) Geothermal heat
c) Sunlight
d) Fossil fuels
Answer: c) Sunlight
5. Which of the following is an example of a decomposer in an ecosystem?
a) Rabbit
b) Earthworm
c) Hawk
d) Oak tree
Answer: b) Earthworm
6. What is the process by which water is released from the leaves of plants into
the atmosphere?
a) Transpiration
b) Precipitation
c) Condensation
d) Evaporation
Answer: a) Transpiration
7. Which of the following terms describes the total mass of living organisms in a
given area?
a) Biomass
b) Biodiversity
c) Biome
d) Biogeochemical cycle
Answer: a) Biomass
8. What is the term for the feeding relationships among different species in an
ecosystem?
a) Symbiosis
b) Trophic levels
c) Competition
d) Predation
, 11. What is the ultimate source of energy for all ecosystems on Earth?
a) Wind
b) Geothermal heat
c) Sunlight
d) Fossil fuels
Answer: c) Sunlight
12. Which of the following is an example of a keystone species in an
ecosystem?
a) Oak tree
b) Earthworm
c) Sea otter
d) Rabbit
Answer: c) Sea otter
13. What is the term for the process by which nutrients are returned to the
soil from dead organisms and waste materials?
a) Decomposition
b) Erosion
c) Precipitation
d) Transpiration
Answer: a) Decomposition
14. Which of the following is a major greenhouse gas responsible for
trapping heat in the Earth's atmosphere?
a) Oxygen
b) Nitrogen
c) Carbon dioxide
d) Hydrogen
Answer: c) Carbon dioxide
15. Which of the following is a characteristic of a terrestrial ecosystem?
a) It is found in water bodies.
b) It has high salinity.
c) It is located on land.
d) It lacks plants.
Answer: c) It is located on land.
16. What is the term for the process by which two species evolve in
response to changes in each other over time?
a) Mutualism
b) Coevolution
c) Competition
d) Predation
Answer: b) Coevolution
17. Which of the following best describes a climax community in ecological
succession?
a) The initial stage of succession
b) A stable and mature community
c) A community with no biodiversity
d) A community dominated by pioneer species
Answer: b) A stable and mature community
18. What is the primary role of decomposers in an ecosystem?
a) To capture sunlight for energy
b) To break down dead organic matter
ecosystems:
1. What is an ecosystem?
a) A single organism
b) A group of unrelated species
c) A community of organisms and their physical environment
d) A collection of rocks and minerals
Answer: c) A community of organisms and their physical
environment
2. Which of the following is a biotic component of an ecosystem?
a) Soil
b) Temperature
) Trees
d) Sunlight
Answer: c) Trees
3. Which gas is essential for photosynthesis in plants?
a) Oxygen
b) Nitrogen
c) Carbon dioxide
d) Hydrogen
Answer: c) Carbon dioxide
4. What is the primary source of energy in most ecosystems?
a) Wind
b) Geothermal heat
c) Sunlight
d) Fossil fuels
Answer: c) Sunlight
5. Which of the following is an example of a decomposer in an ecosystem?
a) Rabbit
b) Earthworm
c) Hawk
d) Oak tree
Answer: b) Earthworm
6. What is the process by which water is released from the leaves of plants into
the atmosphere?
a) Transpiration
b) Precipitation
c) Condensation
d) Evaporation
Answer: a) Transpiration
7. Which of the following terms describes the total mass of living organisms in a
given area?
a) Biomass
b) Biodiversity
c) Biome
d) Biogeochemical cycle
Answer: a) Biomass
8. What is the term for the feeding relationships among different species in an
ecosystem?
a) Symbiosis
b) Trophic levels
c) Competition
d) Predation
, 11. What is the ultimate source of energy for all ecosystems on Earth?
a) Wind
b) Geothermal heat
c) Sunlight
d) Fossil fuels
Answer: c) Sunlight
12. Which of the following is an example of a keystone species in an
ecosystem?
a) Oak tree
b) Earthworm
c) Sea otter
d) Rabbit
Answer: c) Sea otter
13. What is the term for the process by which nutrients are returned to the
soil from dead organisms and waste materials?
a) Decomposition
b) Erosion
c) Precipitation
d) Transpiration
Answer: a) Decomposition
14. Which of the following is a major greenhouse gas responsible for
trapping heat in the Earth's atmosphere?
a) Oxygen
b) Nitrogen
c) Carbon dioxide
d) Hydrogen
Answer: c) Carbon dioxide
15. Which of the following is a characteristic of a terrestrial ecosystem?
a) It is found in water bodies.
b) It has high salinity.
c) It is located on land.
d) It lacks plants.
Answer: c) It is located on land.
16. What is the term for the process by which two species evolve in
response to changes in each other over time?
a) Mutualism
b) Coevolution
c) Competition
d) Predation
Answer: b) Coevolution
17. Which of the following best describes a climax community in ecological
succession?
a) The initial stage of succession
b) A stable and mature community
c) A community with no biodiversity
d) A community dominated by pioneer species
Answer: b) A stable and mature community
18. What is the primary role of decomposers in an ecosystem?
a) To capture sunlight for energy
b) To break down dead organic matter
