Community Ecology Examination
Questions and Correct Answers
(Verified Answers) Plus Rationales 2026
Q&A | Instant Download Pdf
1. Community ecology is the study of
A. Individual organisms only
B. Cell structure
C. Genetic inheritance
D. Interactions among species in communities
Correct Answer: D. Interactions among species in communities
Rationale: Community ecology examines how different species interact with one
another and their environment.
2. A biological community consists of
A. One organism only
B. One species only
C. Abiotic factors only
D. Multiple interacting species
Correct Answer: D. Multiple interacting species
Rationale: A community includes populations of different species living and
interacting in the same area.
3. A population is defined as
,A. All organisms on Earth
B. All ecosystems together
C. Different species in one area
D. Members of the same species in an area
Correct Answer: D. Members of the same species in an area
Rationale: A population contains individuals of the same species occupying a
specific location.
4. Species richness refers to
A. Number of individuals of one species
B. Size of organisms
C. Population growth rate
D. Number of different species in a community
Correct Answer: D. Number of different species in a community
Rationale: Species richness measures the number of species present.
5. Species diversity includes
A. Only species number
B. Only population size
C. Only genetic variation
D. Species richness and relative abundance
Correct Answer: D. Species richness and relative abundance
Rationale: Diversity considers both the number of species and how evenly
individuals are distributed.
6. Species evenness describes
A. Species extinction rate
B. Number of habitats
,C. Number of predators
D. The distribution of individuals among species
Correct Answer: D. The distribution of individuals among species
Rationale: Evenness measures how equally individuals are spread among species.
7. A species that has a disproportionately large effect on its community is called
a
A. Rare species
B. Invasive species
C. Pioneer species
D. Keystone species
Correct Answer: D. Keystone species
Rationale: Keystone species strongly influence community structure despite
sometimes having low abundance.
8. The removal of a keystone species often causes
A. No ecological change
B. Increased biodiversity always
C. Ecosystem stability
D. Major changes in community structure
Correct Answer: D. Major changes in community structure
Rationale: Keystone species maintain important ecological relationships.
9. A species’ role in its ecosystem is called its
A. Habitat
B. Population
C. Territory
D. Niche
, Correct Answer: D. Niche
Rationale: A niche describes how a species uses resources and interacts within an
ecosystem.
10. The place where an organism lives is its
A. Niche
B. Competition
C. Interaction
D. Habitat
Correct Answer: D. Habitat
Rationale: Habitat refers to the physical location where an organism lives.
11. Competition occurs when organisms
A. Help each other
B. Avoid all interactions
C. Share unlimited resources
D. Use the same limited resources
Correct Answer: D. Use the same limited resources
Rationale: Competition arises when organisms require the same scarce resources.
12. Interspecific competition occurs between
A. Individuals of the same species
B. Cells of one organism
C. Different ecosystems
D. Different species
Correct Answer: D. Different species
Rationale: Interspecific competition occurs between members of different species.
Questions and Correct Answers
(Verified Answers) Plus Rationales 2026
Q&A | Instant Download Pdf
1. Community ecology is the study of
A. Individual organisms only
B. Cell structure
C. Genetic inheritance
D. Interactions among species in communities
Correct Answer: D. Interactions among species in communities
Rationale: Community ecology examines how different species interact with one
another and their environment.
2. A biological community consists of
A. One organism only
B. One species only
C. Abiotic factors only
D. Multiple interacting species
Correct Answer: D. Multiple interacting species
Rationale: A community includes populations of different species living and
interacting in the same area.
3. A population is defined as
,A. All organisms on Earth
B. All ecosystems together
C. Different species in one area
D. Members of the same species in an area
Correct Answer: D. Members of the same species in an area
Rationale: A population contains individuals of the same species occupying a
specific location.
4. Species richness refers to
A. Number of individuals of one species
B. Size of organisms
C. Population growth rate
D. Number of different species in a community
Correct Answer: D. Number of different species in a community
Rationale: Species richness measures the number of species present.
5. Species diversity includes
A. Only species number
B. Only population size
C. Only genetic variation
D. Species richness and relative abundance
Correct Answer: D. Species richness and relative abundance
Rationale: Diversity considers both the number of species and how evenly
individuals are distributed.
6. Species evenness describes
A. Species extinction rate
B. Number of habitats
,C. Number of predators
D. The distribution of individuals among species
Correct Answer: D. The distribution of individuals among species
Rationale: Evenness measures how equally individuals are spread among species.
7. A species that has a disproportionately large effect on its community is called
a
A. Rare species
B. Invasive species
C. Pioneer species
D. Keystone species
Correct Answer: D. Keystone species
Rationale: Keystone species strongly influence community structure despite
sometimes having low abundance.
8. The removal of a keystone species often causes
A. No ecological change
B. Increased biodiversity always
C. Ecosystem stability
D. Major changes in community structure
Correct Answer: D. Major changes in community structure
Rationale: Keystone species maintain important ecological relationships.
9. A species’ role in its ecosystem is called its
A. Habitat
B. Population
C. Territory
D. Niche
, Correct Answer: D. Niche
Rationale: A niche describes how a species uses resources and interacts within an
ecosystem.
10. The place where an organism lives is its
A. Niche
B. Competition
C. Interaction
D. Habitat
Correct Answer: D. Habitat
Rationale: Habitat refers to the physical location where an organism lives.
11. Competition occurs when organisms
A. Help each other
B. Avoid all interactions
C. Share unlimited resources
D. Use the same limited resources
Correct Answer: D. Use the same limited resources
Rationale: Competition arises when organisms require the same scarce resources.
12. Interspecific competition occurs between
A. Individuals of the same species
B. Cells of one organism
C. Different ecosystems
D. Different species
Correct Answer: D. Different species
Rationale: Interspecific competition occurs between members of different species.
