WorksheetsEcology and Biogeochemical Cycles Assessment
Total questions: 20
Worksheet time: 10mins
Which biogeochemical cycle represents the movement of carbon through Earth's systems?
Nitrogen cycle
Carbon cycle
Phosphorus cycle
Water cycle
What is the primary source of energy in most ecosystems?
Decomposers
The Sun
Consumers
Minerals
In a food chain, what percentage of energy is typically transferred from one trophic level to the next?
90%
50%
10%
1%
What is carrying capacity?
The maximum population size an environment can support
The minimum number of organisms needed for survival
The rate at which organisms reproduce
The amount of food available in an ecosystem
Which of the following is a density-dependent limiting factor?
Temperature
Natural disasters
Competition for resources
Drought
What type of succession occurs on bare rock where no soil exists?
Secondary succession
Primary succession
Tertiary succession
Climax succession
Which organisms convert nitrogen gas into a usable form for plants?
Decomposers
Nitrogen-fixing bacteria
Consumers
Producers
In a food web, what term describes an organism that eats both plants and animals?
Producer
Decomposer
Omnivore
Herbivore
What is the term for all the populations of different species living in the same area?
Community
Population
Ecosystem
Biosphere
Which factor would NOT affect population density?
Disease
Food availability
The color of organisms
Predation
What happens during ecological succession?
Communities remain unchanged
Communities change over time in a predictable way
All organisms die out
Only one species survives
Which best describes the phosphorus cycle?
It occurs primarily in the atmosphere
It involves only living organisms
It moves through rocks, soil, water, and organisms
It only affects plants
What is the role of decomposers in an ecosystem?
Produce their own food
Break down dead organisms
Eat only plants
Convert sunlight to energy
Which represents the correct order in a typical food chain?
Producer → Consumer → Decomposer
Decomposer → Producer → Consumer
What type of relationship exists when two species compete for the same resource?
Mutualism
Competition
Commensalism
Parasitism
During which process do plants release oxygen into the atmosphere?
Respiration
Decomposition
Photosynthesis
Nitrogen fixation
What is the term for organisms that make their own food?
Heterotrophs
Autotrophs
Consumers
Decomposers
Which is an example of secondary succession?
Volcanic island formation
Forest recovery after a fire
Glacier retreat
Rock weathering
What happens to most of the energy at each trophic level?
It is stored as fat
It is lost as heat
It is converted to water
It is transformed into protein
Which cycle includes evaporation and precipitation?
Carbon cycle
Nitrogen cycle
Water cycle
Phosphorus cycle
