Principles of Ecology - Exam 2 Practice 2026 – UCF
1. Which survivorship curve is characterized by high mortality rates for the
young but low mortality rates for individuals that survive to old age?
A. Type III
B. Type II
C. Type I
D. Type IV
Answer: A
Rationale: Type III survivorship curves represent species where most individuals die
young, but those that survive have a high probability of living to an old age, common in
many fish and plants.
2. In the logistic growth equation, what does ‘K’ represent?
A. The intrinsic rate of increase
B. The population size at time t
C. The carrying capacity
D. The generation time
Answer: C
Rationale: In the logistic equation dN/dt = rN(1 - N/K), K stands for the carrying capacity,
which is the maximum population size the environment can sustain.
,3. Which of the following is an example of a density-independent factor that
limits population growth?
A. Competition for food
B. Disease transmission
C. A catastrophic wildfire
D. Predation pressure
Answer: C
Rationale: Density-independent factors, such as weather events or natural disasters, affect
populations regardless of their density, whereas food and disease are density-dependent.
4. What is the term for a life history strategy characterized by a single
reproductive event followed by death?
A. Iteroparity
B. Philopatry
C. Fecundity
D. Semelparity
Answer: D
Rationale: Semelparity refers to organisms that reproduce once in their lifetime and then
die, such as Pacific salmon or agave plants.
5. According to the Competitive Exclusion Principle, what happens when two
species compete for the exact same limiting resource?
A. They will coexist indefinitely
B. They will switch to a mutualistic relationship
C. Both species will increase in population
D. One species will eventually go extinct locally
Answer: D
, Rationale: The Competitive Exclusion Principle states that two species competing for the
same limiting resource cannot coexist at constant population values; one will be more
efficient and exclude the other.
6. What is the difference between a species’ fundamental niche and its realized
niche?
A. The realized niche is the actual space a species occupies due to biotic interactions like competition
B. The fundamental niche includes abiotic factors, while the realized niche only includes biotic factors
C. The fundamental niche is smaller than the realized niche
D. There is no difference between the two terms
Answer: A
Rationale: The fundamental niche is the full range of conditions a species can survive in,
while the realized niche is the actual range it occupies after accounting for interactions like
competition and predation.
7. Which type of competition occurs when individuals of one species physically
prevent individuals of another species from accessing a resource?
A. Exploitative competition
B. Intraspecific competition
C. Apparent competition
D. Interference competition
Answer: D
Rationale: Interference competition involves direct interaction where one individual
excludes another from a resource by aggression or physical obstruction.
1. Which survivorship curve is characterized by high mortality rates for the
young but low mortality rates for individuals that survive to old age?
A. Type III
B. Type II
C. Type I
D. Type IV
Answer: A
Rationale: Type III survivorship curves represent species where most individuals die
young, but those that survive have a high probability of living to an old age, common in
many fish and plants.
2. In the logistic growth equation, what does ‘K’ represent?
A. The intrinsic rate of increase
B. The population size at time t
C. The carrying capacity
D. The generation time
Answer: C
Rationale: In the logistic equation dN/dt = rN(1 - N/K), K stands for the carrying capacity,
which is the maximum population size the environment can sustain.
,3. Which of the following is an example of a density-independent factor that
limits population growth?
A. Competition for food
B. Disease transmission
C. A catastrophic wildfire
D. Predation pressure
Answer: C
Rationale: Density-independent factors, such as weather events or natural disasters, affect
populations regardless of their density, whereas food and disease are density-dependent.
4. What is the term for a life history strategy characterized by a single
reproductive event followed by death?
A. Iteroparity
B. Philopatry
C. Fecundity
D. Semelparity
Answer: D
Rationale: Semelparity refers to organisms that reproduce once in their lifetime and then
die, such as Pacific salmon or agave plants.
5. According to the Competitive Exclusion Principle, what happens when two
species compete for the exact same limiting resource?
A. They will coexist indefinitely
B. They will switch to a mutualistic relationship
C. Both species will increase in population
D. One species will eventually go extinct locally
Answer: D
, Rationale: The Competitive Exclusion Principle states that two species competing for the
same limiting resource cannot coexist at constant population values; one will be more
efficient and exclude the other.
6. What is the difference between a species’ fundamental niche and its realized
niche?
A. The realized niche is the actual space a species occupies due to biotic interactions like competition
B. The fundamental niche includes abiotic factors, while the realized niche only includes biotic factors
C. The fundamental niche is smaller than the realized niche
D. There is no difference between the two terms
Answer: A
Rationale: The fundamental niche is the full range of conditions a species can survive in,
while the realized niche is the actual range it occupies after accounting for interactions like
competition and predation.
7. Which type of competition occurs when individuals of one species physically
prevent individuals of another species from accessing a resource?
A. Exploitative competition
B. Intraspecific competition
C. Apparent competition
D. Interference competition
Answer: D
Rationale: Interference competition involves direct interaction where one individual
excludes another from a resource by aggression or physical obstruction.
