Energy Flow in Ecosystems
What is the original source of energy for most ecosystems?
A) Wind
B) Soil
C) Sunlight
D) Water
C) Sunlight
Which of the following is a biotic factor?
A) Sunlight
B) Temperature
C) Number of predators
D) pH of water
C) Number of predators
Which of the following is an abiotic factor?
A) Number of predators
B) Salinity of water
C) Type of vegetation
D) Number of mates
B) Salinity of water
Which of the following is a human activity that affects ecosystems?
A) Tidal movement
B) Land clearing
C) Seasonal rainfall
D) Dissolved oxygen
B) Land clearing
What does a food web show?
A) How fast animals grow
B) Only predator-prey relationships
C) Interconnected food chains in an ecosystem
D) The number of plants in an area
C) Interconnected food chains in an ecosystem
In a food chain, which organism gets the most energy directly from the sun?
A) Primary consumer
B) Producer
C) Secondary consumer
D) Decomposer
B) Producer
How can an increase in predators affect a prey population?
A) It increases birth rates
B) It leads to more food for prey
C) It decreases the prey population
D) It causes mutations in prey
C) It decreases the prey population
Why might fish struggle to survive in water with low oxygen (O₂)?
A) They cannot see their food
B) They need oxygen to breathe
C) It makes them more visible to predators
D) It affects water salinity
B) They need oxygen to breathe
How does land clearance affect animals in an ecosystem?
A) Increases food supply
B) Creates more breeding grounds
C) Reduces available habitat
D) Reduces temperature variation
C) Reduces available habitat
If all producers in a food web die, what is most likely to happen?
A) Consumers will eventually die
B) Consumers will find new food
C) Nothing will change
D) Decomposers will increase
A) Consumers will eventually die
Which of the following best describes the flow of energy in a food web?
A) Energy cycles back to the sun
B) Energy is stored and never lost
C) Energy flows in one direction and decreases at each level
D) Energy flows equally to all organisms
C) Energy flows in one direction and decreases at each level
What would likely happen if the number of mates available in a population decreased?
A) Birth rates would decrease
B) Predators would increase
C) Population would grow quickly
D) Food availability would increase
A) Birth rates would decrease
How does light availability affect plant growth in aquatic ecosystems?
A) More light reduces plant growth
B) Less light helps plants grow
C) Plants do not need light in water
D) Plants need light for photosynthesis
D) Plants need light for photosynthesis
What is a potential consequence of climate change on ecosystems?
A) Loss of species due to temperature changes
B) Increased biodiversity
C) Stable food webs
D) Decrease in abiotic factors
A) Loss of species due to temperature changes
In a food web, what would happen if a top predator were removed?
A) Nothing changes
B) Prey populations would increase
C) Producers would become extinct
D) Energy would stop flowing
B) Prey populations would increase
Why are there fewer top predators than herbivores in an ecosystem?
A) Top predators are smaller
B) Herbivores reproduce slower
C) Herbivores are better at hunting
D) Energy is lost at each trophic level
D) Energy is lost at each trophic level
If a disease spreads quickly through a population, what is the likely result?
A) Increase in predators
B) Sharp decrease in population
C) More available mates
D) Stabilisation of food webs
B) Sharp decrease in population
What is most likely to happen in an estuary with rapidly changing salinity?
A) Organisms adapt easily
B) Biodiversity increases
C) Only highly tolerant species will survive
D) Clarity of water improves
C) Only highly tolerant species will survive
How does climate change indirectly affect food webs?
A) By removing all predators
B) By altering abiotic conditions that affect producers
C) By providing more mates
D) By increasing predator-prey balance
B) By altering abiotic conditions that affect producers
Which of the following best explains why food webs are more stable than food chains?
A) They include decomposers
B) They have more plants
C) They offer multiple feeding pathways
D) They are easier to draw
C) They offer multiple feeding pathways