ECOLOGY AND POPULATION DYNAMICS EXAMINATION
QUESTIONS WITH 100% VERIFIED ANSWERS
1. Which of the following best describes the concept of a
“metapopulation”?
A) A single, large population with no migration between subgroups
B) A set of spatially separated populations of the same species
connected by dispersal
C) A population that has reached carrying capacity and stopped growing
D) A group of different species occupying the same habitat
Explanation: A metapopulation consists of distinct local populations
(subpopulations) linked by occasional individual movement and gene
flow. Extinct patches can be recolonized from occupied ones, which is
key to regional persistence.
𝑑𝑁 𝑁
2. In the logistic growth equation = 𝑟𝑁 (1− ), what does “𝐾”
𝑑𝑡 𝐾
represent?
A) The intrinsic rate of increase
B) The population density at which births exceed deaths
C) The carrying capacity of the environment
D) The time needed to reach half the maximum population
Explanation: 𝐾 is the carrying capacity—the maximum population size
an environment can sustain indefinitely given available resources.
,3. A population of 500 birds has 80 births and 40 deaths per year, with
20 immigrants and 10 emigrants. What is the per capita growth rate
(r)?
A) 0.05
B) 0.06
C) 0.10
D) 0.12
Explanation: Net change = (80-40) + (20-10) = 50. Per capita r = 50/500
= 0.10.
4. Which type of survivorship curve is typical of humans in developed
countries?
A) Type I (high juvenile survival, most deaths in old age)
B) Type II (constant death rate across ages)
C) Type III (very high juvenile mortality)
D) Type IV (bimodal mortality peaks)
Explanation: Humans in developed nations show Type I curve: low
early-life mortality, most individuals live to old age before dying.
5. Which of the following is an example of a density-independent
factor?
A) Competition for food
B) Predation rate increasing with prey density
C) Disease transmission rate
D) A volcanic eruption
,Explanation: Density-independent factors affect populations regardless
of density. Volcanic eruptions kill individuals without relation to
population size, unlike competition, predation, or disease.
6. Two species of warblers feed on the same type of insect but forage
in different vertical zones of the same tree. This is an example of:
A) Competitive exclusion
B) Resource partitioning
C) Character displacement
D) Mutualism
Explanation: Resource partitioning reduces direct competition by
allowing species to divide a niche (e.g., space, time, food type). Here,
vertical zones differ.
7. In the Lotka-Volterra predator-prey model, what causes the cyclical
oscillations of both populations?
A) Constant prey growth rate
B) Predator satiation
C) Time lag between predator reproduction and prey consumption
D) Random environmental fluctuations
Explanation: The classic cycles arise because predator numbers
increase after prey increases, then overconsume prey, causing predator
decline, allowing prey recovery—an inherent time lag.
, 8. A population exhibits exponential growth. Which condition is most
likely present?
A) Near carrying capacity
B) Strong density-dependent mortality
C) Abundant resources and no predators
D) High emigration rate
Explanation: Exponential growth occurs when resources are unlimited
and no limiting factors (predators, disease, competition) act, so per
capita growth is constant.
9. In island biogeography theory, the equilibrium number of species
on an island is determined by:
A) Only island size
B) Only distance from mainland
C) Balance between colonization and extinction rates
D) Island latitude only
Explanation: The theory states species richness reaches equilibrium
when colonization rate (new species arriving) equals extinction rate of
species already present. Both island size (affects extinction) and
distance (affects colonization) matter.
10. A keystone species is one that:
A) Has the highest biomass in the community
B) Exerts a disproportionately large effect on community structure
relative to its abundance
QUESTIONS WITH 100% VERIFIED ANSWERS
1. Which of the following best describes the concept of a
“metapopulation”?
A) A single, large population with no migration between subgroups
B) A set of spatially separated populations of the same species
connected by dispersal
C) A population that has reached carrying capacity and stopped growing
D) A group of different species occupying the same habitat
Explanation: A metapopulation consists of distinct local populations
(subpopulations) linked by occasional individual movement and gene
flow. Extinct patches can be recolonized from occupied ones, which is
key to regional persistence.
𝑑𝑁 𝑁
2. In the logistic growth equation = 𝑟𝑁 (1− ), what does “𝐾”
𝑑𝑡 𝐾
represent?
A) The intrinsic rate of increase
B) The population density at which births exceed deaths
C) The carrying capacity of the environment
D) The time needed to reach half the maximum population
Explanation: 𝐾 is the carrying capacity—the maximum population size
an environment can sustain indefinitely given available resources.
,3. A population of 500 birds has 80 births and 40 deaths per year, with
20 immigrants and 10 emigrants. What is the per capita growth rate
(r)?
A) 0.05
B) 0.06
C) 0.10
D) 0.12
Explanation: Net change = (80-40) + (20-10) = 50. Per capita r = 50/500
= 0.10.
4. Which type of survivorship curve is typical of humans in developed
countries?
A) Type I (high juvenile survival, most deaths in old age)
B) Type II (constant death rate across ages)
C) Type III (very high juvenile mortality)
D) Type IV (bimodal mortality peaks)
Explanation: Humans in developed nations show Type I curve: low
early-life mortality, most individuals live to old age before dying.
5. Which of the following is an example of a density-independent
factor?
A) Competition for food
B) Predation rate increasing with prey density
C) Disease transmission rate
D) A volcanic eruption
,Explanation: Density-independent factors affect populations regardless
of density. Volcanic eruptions kill individuals without relation to
population size, unlike competition, predation, or disease.
6. Two species of warblers feed on the same type of insect but forage
in different vertical zones of the same tree. This is an example of:
A) Competitive exclusion
B) Resource partitioning
C) Character displacement
D) Mutualism
Explanation: Resource partitioning reduces direct competition by
allowing species to divide a niche (e.g., space, time, food type). Here,
vertical zones differ.
7. In the Lotka-Volterra predator-prey model, what causes the cyclical
oscillations of both populations?
A) Constant prey growth rate
B) Predator satiation
C) Time lag between predator reproduction and prey consumption
D) Random environmental fluctuations
Explanation: The classic cycles arise because predator numbers
increase after prey increases, then overconsume prey, causing predator
decline, allowing prey recovery—an inherent time lag.
, 8. A population exhibits exponential growth. Which condition is most
likely present?
A) Near carrying capacity
B) Strong density-dependent mortality
C) Abundant resources and no predators
D) High emigration rate
Explanation: Exponential growth occurs when resources are unlimited
and no limiting factors (predators, disease, competition) act, so per
capita growth is constant.
9. In island biogeography theory, the equilibrium number of species
on an island is determined by:
A) Only island size
B) Only distance from mainland
C) Balance between colonization and extinction rates
D) Island latitude only
Explanation: The theory states species richness reaches equilibrium
when colonization rate (new species arriving) equals extinction rate of
species already present. Both island size (affects extinction) and
distance (affects colonization) matter.
10. A keystone species is one that:
A) Has the highest biomass in the community
B) Exerts a disproportionately large effect on community structure
relative to its abundance
