Unit 3: Functioning Ecosystems. 4

What does an ecological niche describe?

• The lifespan of an organism

• The physical space an organism occupies

• The functional role of an organism in an ecosystem

• The genetic makeup of an organism

What is a fundamental niche?

• The physical space a species occupies

• The genetic makeup of a species

• All the potential resources a species can use in its environment

• The actual resources a species uses

What is a realised niche?

• The genetic makeup of a species

• All the potential resources a species can use in its environment

• The actual resources a species uses

• The physical space a species occupies

What principle states that two species with exactly the same niche cannot coexist?

• Resource partitioning principle

• Competitive exclusion principle

• Fundamental niche principle

• Realised niche principle

What happens when one species has even the slightest advantage over another?

• They will merge into a single species

• They will both go extinct

• The one with the advantage will dominate in the long term

• They will coexist peacefully

What is resource partitioning?

• When organisms migrate to new habitats

• When organisms share the same resources

• When organisms fight for the same resources

• When organisms use different resources to avoid competition

What are density-dependent factors?

• Factors that only affect small populations

• Factors that affect population growth regardless of population size

• Factors that do not affect population growth

• Factors that affect population growth as the number of individuals increases

Which of the following is an example of a density-dependent factor?

• Natural disasters

• Climate change

• Competition for resources

• Sunlight availability

What can lead to the extinction of the weaker competitor?

• Mutualism

• Commensalism

• Competitive exclusion

• Resource partitioning

What is the competitive refuge?

• The area where a species competes for resources

• The area where a species can live without competition

• The area where a species finds new resources

• The area where a species migrates to avoid competition