PCB3044 Principles of Ecology Exam 2 Study Guide 2026 – UCF
1. Which type of survivorship curve is characterized by high mortality rates for
the young but high survival rates for individuals that reach adulthood?
A. Type I
B. Type II
C. Type III
D. Type IV
Answer: C
Rationale: Type III survivorship curves are common in species that produce many
offspring with little parental care, such as many fish and marine invertebrates.
2. In the logistic growth equation, dN/dt = rN(1 - N/K), what does the term ‘K’
represent?
A. Intrinsic rate of increase
B. Population density
C. Carrying capacity
D. Survival probability
Answer: C
Rationale: K represents the carrying capacity, which is the maximum population size that
a particular environment can sustain.
,3. Which of the following is an example of a density-independent factor
regulating population growth?
A. Disease transmission
B. A catastrophic wildfire
C. Competition for food
D. Predation pressure
Answer: B
Rationale: Density-independent factors, like weather or natural disasters, affect
population size regardless of the population’s density.
4. According to Grime’s triangular model, plants that are adapted to high stress
but low disturbance environments are called:
A. Ruderals
B. Stress-tolerators
C. Competitors
D. Successional specialists
Answer: B
Rationale: Stress-tolerators are adapted to survive in extreme conditions where resources
are limited but disturbance is infrequent.
5. What is the primary difference between semelparity and iteroparity?
A. The frequency of reproductive events in a lifetime
B. The number of offspring per event
C. The age at first reproduction
D. The amount of parental care provided
Answer: A
Rationale: Semelparous organisms breed only once in their lifetime, while iteroparous
organisms breed multiple times.
, 6. In a metapopulation model, a ‘sink’ patch is defined as a habitat where:
A. Reproduction exceeds mortality
B. Emigration is higher than immigration
C. Mortality exceeds reproduction
D. The population is always at carrying capacity
Answer: C
Rationale: Sink patches rely on immigration from source patches to maintain their
population because local deaths outnumber local births.
7. The Principle of Competitive Exclusion states that:
A. Two species can coexist if they share the same niche
B. Two species competing for the same limiting resource cannot coexist
C. Competition always leads to the extinction of both species
D. Predators prevent competition among prey
Answer: B
Rationale: If two species use the exact same resources in the same way, one will eventually
outcompete the other to local extinction.
8. Which type of competition involves direct physical interaction between
individuals, such as defending a territory?
A. Exploitative competition
B. Interference competition
C. Apparent competition
D. Resource competition
Answer: B
Rationale: Interference competition involves direct behavioral or chemical interactions
that prevent others from accessing a resource.
1. Which type of survivorship curve is characterized by high mortality rates for
the young but high survival rates for individuals that reach adulthood?
A. Type I
B. Type II
C. Type III
D. Type IV
Answer: C
Rationale: Type III survivorship curves are common in species that produce many
offspring with little parental care, such as many fish and marine invertebrates.
2. In the logistic growth equation, dN/dt = rN(1 - N/K), what does the term ‘K’
represent?
A. Intrinsic rate of increase
B. Population density
C. Carrying capacity
D. Survival probability
Answer: C
Rationale: K represents the carrying capacity, which is the maximum population size that
a particular environment can sustain.
,3. Which of the following is an example of a density-independent factor
regulating population growth?
A. Disease transmission
B. A catastrophic wildfire
C. Competition for food
D. Predation pressure
Answer: B
Rationale: Density-independent factors, like weather or natural disasters, affect
population size regardless of the population’s density.
4. According to Grime’s triangular model, plants that are adapted to high stress
but low disturbance environments are called:
A. Ruderals
B. Stress-tolerators
C. Competitors
D. Successional specialists
Answer: B
Rationale: Stress-tolerators are adapted to survive in extreme conditions where resources
are limited but disturbance is infrequent.
5. What is the primary difference between semelparity and iteroparity?
A. The frequency of reproductive events in a lifetime
B. The number of offspring per event
C. The age at first reproduction
D. The amount of parental care provided
Answer: A
Rationale: Semelparous organisms breed only once in their lifetime, while iteroparous
organisms breed multiple times.
, 6. In a metapopulation model, a ‘sink’ patch is defined as a habitat where:
A. Reproduction exceeds mortality
B. Emigration is higher than immigration
C. Mortality exceeds reproduction
D. The population is always at carrying capacity
Answer: C
Rationale: Sink patches rely on immigration from source patches to maintain their
population because local deaths outnumber local births.
7. The Principle of Competitive Exclusion states that:
A. Two species can coexist if they share the same niche
B. Two species competing for the same limiting resource cannot coexist
C. Competition always leads to the extinction of both species
D. Predators prevent competition among prey
Answer: B
Rationale: If two species use the exact same resources in the same way, one will eventually
outcompete the other to local extinction.
8. Which type of competition involves direct physical interaction between
individuals, such as defending a territory?
A. Exploitative competition
B. Interference competition
C. Apparent competition
D. Resource competition
Answer: B
Rationale: Interference competition involves direct behavioral or chemical interactions
that prevent others from accessing a resource.
