Principles of Ecology - Exam 3 Prep 2026 – UCF
1. In the context of life history strategies, what is the term for an organism that
reproduces only once in its lifetime?
A. Iteroparous
B. Viviparous
C. R-selected
D. Semelparous
Answer: D
Rationale: Semelparity refers to the ‘big bang’ reproduction strategy where an organism
invests all its energy into a single reproductive event before death.
2. Which type of survivorship curve is characterized by high mortality rates for
the young but high survival rates for adults?
A. Type III
B. Type II
C. Type I
D. Linear
Answer: A
Rationale: Type III curves are typical for species that produce many offspring but provide
little parental care, such as many fish and invertebrates.
,3. In the logistic growth equation, dN/dt = rN(1 - N/K), what does ‘K’ represent?
A. Intrinsic rate of increase
B. Carrying capacity
C. Population size
D. Generation time
Answer: B
Rationale: K is the carrying capacity, the maximum population size that a particular
environment can sustain.
4. Two species of birds eat the same seeds but forage at different times of the
day. This is an example of:
A. Temporal niche partitioning
B. Competitive exclusion
C. Character displacement
D. Apparent competition
Answer: A
Rationale: Niche partitioning occurs when species divide resources (by space, time, or
type) to minimize competition.
5. Which of the following is an example of a density-independent factor
regulating population growth?
A. Spread of a contagious disease
B. Competition for nesting sites
C. A severe hurricane
D. Predation
Answer: C
Rationale: Density-independent factors, like natural disasters or weather, affect mortality
regardless of how many individuals are in the population.
, 6. According to the Competitive Exclusion Principle, two species cannot coexist
indefinitely if:
A. They share the exact same niche
B. One is a predator of the other
C. They occupy different habitats
D. They have different carrying capacities
Answer: A
Rationale: Gause’s Principle states that two species competing for the same limiting
resource cannot coexist; one will eventually outcompete the other.
7. A harmless fly evolves to look like a stinging wasp. This is an example of:
A. Batesian mimicry
B. Mullerian mimicry
C. Crypsis
D. Aposematism
Answer: A
Rationale: Batesian mimicry occurs when a palatable or harmless species mimics an
unpalatable or harmful one.
8. Which interaction is characterized as (+/0), where one species benefits and
the other is unaffected?
A. Commensalism
B. Parasitism
C. Mutualism
D. Amensalism
Answer: A
Rationale: Commensalism involves one beneficiary and one neutral party, such as
barnacles on a whale.
1. In the context of life history strategies, what is the term for an organism that
reproduces only once in its lifetime?
A. Iteroparous
B. Viviparous
C. R-selected
D. Semelparous
Answer: D
Rationale: Semelparity refers to the ‘big bang’ reproduction strategy where an organism
invests all its energy into a single reproductive event before death.
2. Which type of survivorship curve is characterized by high mortality rates for
the young but high survival rates for adults?
A. Type III
B. Type II
C. Type I
D. Linear
Answer: A
Rationale: Type III curves are typical for species that produce many offspring but provide
little parental care, such as many fish and invertebrates.
,3. In the logistic growth equation, dN/dt = rN(1 - N/K), what does ‘K’ represent?
A. Intrinsic rate of increase
B. Carrying capacity
C. Population size
D. Generation time
Answer: B
Rationale: K is the carrying capacity, the maximum population size that a particular
environment can sustain.
4. Two species of birds eat the same seeds but forage at different times of the
day. This is an example of:
A. Temporal niche partitioning
B. Competitive exclusion
C. Character displacement
D. Apparent competition
Answer: A
Rationale: Niche partitioning occurs when species divide resources (by space, time, or
type) to minimize competition.
5. Which of the following is an example of a density-independent factor
regulating population growth?
A. Spread of a contagious disease
B. Competition for nesting sites
C. A severe hurricane
D. Predation
Answer: C
Rationale: Density-independent factors, like natural disasters or weather, affect mortality
regardless of how many individuals are in the population.
, 6. According to the Competitive Exclusion Principle, two species cannot coexist
indefinitely if:
A. They share the exact same niche
B. One is a predator of the other
C. They occupy different habitats
D. They have different carrying capacities
Answer: A
Rationale: Gause’s Principle states that two species competing for the same limiting
resource cannot coexist; one will eventually outcompete the other.
7. A harmless fly evolves to look like a stinging wasp. This is an example of:
A. Batesian mimicry
B. Mullerian mimicry
C. Crypsis
D. Aposematism
Answer: A
Rationale: Batesian mimicry occurs when a palatable or harmless species mimics an
unpalatable or harmful one.
8. Which interaction is characterized as (+/0), where one species benefits and
the other is unaffected?
A. Commensalism
B. Parasitism
C. Mutualism
D. Amensalism
Answer: A
Rationale: Commensalism involves one beneficiary and one neutral party, such as
barnacles on a whale.
