Principles of Ecology - Exam 3 Prep 2026 – UCF
1. Which of the following describes the maximum population size that a
particular environment can support indefinitely?
A. Biotic potential
B. Intrinsic rate of increase
C. Exponential limit
D. Carrying capacity
Answer: D
Rationale: Carrying capacity (K) is the maximum number of individuals of a population
that a specific environment can support based on resource availability.
2. In the logistic growth equation, what happens as the population size (N)
approaches the carrying capacity (K)?
A. The growth rate accelerates
B. The growth rate approaches zero
C. The population crashes immediately
D. The value of r increases
Answer: B
Rationale: As N approaches K, the term (K-N)/K approaches zero, which reduces the
overall growth rate (dN/dt) to zero, resulting in a plateau.
,3. Which type of survivorship curve is characterized by high mortality rates early
in life, followed by high survival rates for the remaining life span?
A. Type III
B. Type II
C. Type I
D. Type IV
Answer: A
Rationale: Type III curves are typical of species that produce many offspring but provide
little care, such as many fish and marine invertebrates.
4. An organism that reproduces only once in its lifetime before dying is known
as:
A. Iteroparous
B. Semelparous
C. Viviparous
D. K-selected
Answer: B
Rationale: Semelparity refers to a ‘big bang’ reproduction strategy where an organism
invests all its energy into a single reproductive event.
5. According to the Competitive Exclusion Principle, two species cannot coexist
if:
A. They compete for the exact same limiting resource
B. They have the same fundamental niche
C. They occupy different geographical areas
D. One species is a predator of the other
Answer: A
, Rationale: Gause’s Principle states that two species competing for the same limiting
resource cannot coexist at constant population values; one will eventually outcompete the
other.
6. Which of the following is a density-independent factor that regulates
population size?
A. A catastrophic wildfire
B. Competition for food
C. Spread of a contagious disease
D. Predation pressure
Answer: A
Rationale: Density-independent factors, like natural disasters or weather, affect mortality
regardless of how many individuals are in the population.
7. What is the term for the process where two species evolve different traits to
reduce competition when living in the same area?
A. Character displacement
B. Resource partitioning
C. Convergent evolution
D. Commensalism
Answer: A
Rationale: Character displacement is the evolutionary divergence in traits between two
species that live together to minimize niche overlap.
1. Which of the following describes the maximum population size that a
particular environment can support indefinitely?
A. Biotic potential
B. Intrinsic rate of increase
C. Exponential limit
D. Carrying capacity
Answer: D
Rationale: Carrying capacity (K) is the maximum number of individuals of a population
that a specific environment can support based on resource availability.
2. In the logistic growth equation, what happens as the population size (N)
approaches the carrying capacity (K)?
A. The growth rate accelerates
B. The growth rate approaches zero
C. The population crashes immediately
D. The value of r increases
Answer: B
Rationale: As N approaches K, the term (K-N)/K approaches zero, which reduces the
overall growth rate (dN/dt) to zero, resulting in a plateau.
,3. Which type of survivorship curve is characterized by high mortality rates early
in life, followed by high survival rates for the remaining life span?
A. Type III
B. Type II
C. Type I
D. Type IV
Answer: A
Rationale: Type III curves are typical of species that produce many offspring but provide
little care, such as many fish and marine invertebrates.
4. An organism that reproduces only once in its lifetime before dying is known
as:
A. Iteroparous
B. Semelparous
C. Viviparous
D. K-selected
Answer: B
Rationale: Semelparity refers to a ‘big bang’ reproduction strategy where an organism
invests all its energy into a single reproductive event.
5. According to the Competitive Exclusion Principle, two species cannot coexist
if:
A. They compete for the exact same limiting resource
B. They have the same fundamental niche
C. They occupy different geographical areas
D. One species is a predator of the other
Answer: A
, Rationale: Gause’s Principle states that two species competing for the same limiting
resource cannot coexist at constant population values; one will eventually outcompete the
other.
6. Which of the following is a density-independent factor that regulates
population size?
A. A catastrophic wildfire
B. Competition for food
C. Spread of a contagious disease
D. Predation pressure
Answer: A
Rationale: Density-independent factors, like natural disasters or weather, affect mortality
regardless of how many individuals are in the population.
7. What is the term for the process where two species evolve different traits to
reduce competition when living in the same area?
A. Character displacement
B. Resource partitioning
C. Convergent evolution
D. Commensalism
Answer: A
Rationale: Character displacement is the evolutionary divergence in traits between two
species that live together to minimize niche overlap.
