WorksheetsEcosystem Succession and Community Dynamics
Total questions: 20
Worksheet time: 10mins
Which term describes a relationship where one organism benefits and the other is harmed?
Mutualism
Parasitism
Commensalism
Competition
What is the primary role of a keystone species in an ecosystem?
To provide the most biomass
To maintain the structure and stability of a community
To be the most numerous species
To be the first species to colonize an area
Which of the following best defines ecological succession?
The process by which organisms adapt to their environment
The gradual change in community composition over time
The movement of animals from one place to another
The competition between species for resources
Which of the following is an example of mutualism?
A tick feeding on a dog
Bees pollinating flowers
A lion hunting a zebra
Moss growing on a tree
What is resource partitioning?
The division of resources among individuals of the same species
The process by which similar species use different resources to reduce competition
The sharing of food between predator and prey
The elimination of a species from a community
Which species is most likely to be affected first by a disturbance in an ecosystem?
Foundation species
Endangered species
Dominant species
Keystone species
Which of the following best describes a foundation species?
A species that has a large effect on its environment relative to its abundance
A species that creates or maintains habitat for other species
A species that is at risk of extinction
A species that is the most common in a community
What is the main effect of increased species diversity on an ecosystem?
Decreased stability
Increased stability
Increased competition only
Decreased resource availability
Which of the following is an example of commensalism?
Barnacles attaching to a whale
Wolves hunting deer
Tapeworms in a dog’s intestine
Ants protecting aphids
Which process is most likely to occur after a forest fire destroys a large area of trees?
Primary succession
Secondary succession
Resource partitioning
Mutualism
Given a scenario where two bird species feed on the same tree but at different heights, which ecological concept is being demonstrated?
Competition
Resource partitioning
Parasitism
Predation
A population of rabbits increases rapidly in a grassland. Which of the following is a likely effect on the community structure?
Decrease in grass availability
Increase in predator populations
Both A and B
No effect
If a keystone species is removed from a community, what is the most likely outcome?
The community remains unchanged
The community structure becomes less stable
Only the keystone species is affected
All species become extinct
How does competition influence the ecological niches of species within a community?
It causes species to occupy identical niches
It leads to resource partitioning and niche differentiation
It eliminates all but one species
It has no effect on niches
A disturbance removes all vegetation from a region, leaving only bare rock. Which sequence of events best describes the process that follows?
Secondary succession, then primary succession
Primary succession, then establishment of pioneer species, then climax community
Climax community, then pioneer species, then primary succession
Resource partitioning, then mutualism
Why might an ecosystem with low species diversity be more vulnerable to environmental changes?
Fewer species means less competition
There are fewer functional roles filled, reducing resilience
More species means more predators
Low diversity increases resource partitioning
A scientist observes that after a volcanic eruption, lichens and mosses are the first organisms to colonize the area. What role do these organisms play in succession?
They are climax species
They are pioneer species that initiate primary succession
They are keystone species
They are foundation species
A community is observed to have high species diversity and a stable population size over many years. What can be inferred about the ecosystem?
It is likely resilient to disturbances
It is in the early stages of succession
It is dominated by a single species
It is experiencing frequent extinctions
A researcher wants to determine the impact of removing a foundation species from a salt marsh. Which approach would best allow the researcher to predict the long-term effects on community structure?
Review the definition of foundation species
Conduct a controlled experiment and monitor changes in species composition over time
Count the number of individuals before removal
Observe a different ecosystem
Given a scenario where an invasive species outcompetes native species for resources, how might this affect the process of ecological succession in the community?
It will have no effect on succession
It may alter the normal succession pattern and reduce native biodiversity
It will speed up the return to a climax community
It will only affect the invasive species
