PCB3044 Principles of Ecology Exam 2
Questions & Answers | Grade A | 100%
Correct - WCU
1. According to Grime’s classification of plant life histories, plants that are
adapted to high stress and low disturbance environments are known as:
A. Ruderals
B. Competitors
C. Stress-tolerators
D. Generalists
Answer: C
Explanation: Stress-tolerators are adapted to high-stress environments where resources
are limited but disturbance is low.
2. Which of the following equations represents the geometric growth of a
population with discrete generations?
A. dN/dt = rN
B. Nt = N0 * λ^t
C. dN/dt = rN(1-N/K)
D. Nt = N0 * e^(rt)
Answer: B
Explanation: Geometric growth for discrete generations uses the finite rate of increase (λ).
,3. In the logistic growth equation, what does the term ‘K’ represent?
A. Intrinsic rate of increase
B. The point of maximum growth
C. Population size at time t
D. Carrying capacity
Answer: D
Explanation: K is the carrying capacity, the maximum population size the environment can
support.
4. A Type III survivorship curve is characterized by:
A. High mortality in early life and higher survival for older individuals
B. Constant mortality rates across all ages
C. Low survival in early life and low mortality in early life
D. High survival in early life and high mortality later
Answer: A
Explanation: Type III curves show high juvenile mortality, typical of species that produce
many offspring but provide little care.
5. An organism that reproduces only once in its lifetime is described as:
A. Iteroparous
B. Semelparous
C. Viviparous
D. Dioecious
Answer: B
Explanation: Semelparity refers to organisms that have a single reproductive event before
death.
, 6. Density-independent factors that regulate population size include:
A. Competition for resources
B. Extreme weather events
C. Disease transmission
D. Predation pressure
Answer: B
Explanation: Weather events affect mortality regardless of the population density.
7. In a metapopulation, the term ‘source’ patch refers to:
A. A patch where the death rate exceeds the birth rate
B. A patch where the birth rate exceeds the death rate
C. A patch that is frequently colonized but never produces emigrants
D. A patch that is always empty
Answer: B
Explanation: Source patches produce excess individuals that can emigrate to ‘sink’
patches.
8. The competitive exclusion principle states that:
A. Two species can coexist indefinitely if they share the same niche
B. Two species with identical niches cannot coexist indefinitely
C. Competition always leads to the extinction of both species
D. Predation is more important than competition in structuring communities
Answer: B
Explanation: Gause’s principle states that if two species compete for the same limiting
resource, one will eventually exclude the other.
Questions & Answers | Grade A | 100%
Correct - WCU
1. According to Grime’s classification of plant life histories, plants that are
adapted to high stress and low disturbance environments are known as:
A. Ruderals
B. Competitors
C. Stress-tolerators
D. Generalists
Answer: C
Explanation: Stress-tolerators are adapted to high-stress environments where resources
are limited but disturbance is low.
2. Which of the following equations represents the geometric growth of a
population with discrete generations?
A. dN/dt = rN
B. Nt = N0 * λ^t
C. dN/dt = rN(1-N/K)
D. Nt = N0 * e^(rt)
Answer: B
Explanation: Geometric growth for discrete generations uses the finite rate of increase (λ).
,3. In the logistic growth equation, what does the term ‘K’ represent?
A. Intrinsic rate of increase
B. The point of maximum growth
C. Population size at time t
D. Carrying capacity
Answer: D
Explanation: K is the carrying capacity, the maximum population size the environment can
support.
4. A Type III survivorship curve is characterized by:
A. High mortality in early life and higher survival for older individuals
B. Constant mortality rates across all ages
C. Low survival in early life and low mortality in early life
D. High survival in early life and high mortality later
Answer: A
Explanation: Type III curves show high juvenile mortality, typical of species that produce
many offspring but provide little care.
5. An organism that reproduces only once in its lifetime is described as:
A. Iteroparous
B. Semelparous
C. Viviparous
D. Dioecious
Answer: B
Explanation: Semelparity refers to organisms that have a single reproductive event before
death.
, 6. Density-independent factors that regulate population size include:
A. Competition for resources
B. Extreme weather events
C. Disease transmission
D. Predation pressure
Answer: B
Explanation: Weather events affect mortality regardless of the population density.
7. In a metapopulation, the term ‘source’ patch refers to:
A. A patch where the death rate exceeds the birth rate
B. A patch where the birth rate exceeds the death rate
C. A patch that is frequently colonized but never produces emigrants
D. A patch that is always empty
Answer: B
Explanation: Source patches produce excess individuals that can emigrate to ‘sink’
patches.
8. The competitive exclusion principle states that:
A. Two species can coexist indefinitely if they share the same niche
B. Two species with identical niches cannot coexist indefinitely
C. Competition always leads to the extinction of both species
D. Predation is more important than competition in structuring communities
Answer: B
Explanation: Gause’s principle states that if two species compete for the same limiting
resource, one will eventually exclude the other.
