BSC2011L - Practice Quiz 9

Population Ecology

C

Which of the following will increase population size?
A. Deaths and emigration
B. Births and emigration
C. Births and immigration
D. Immigration and deaths

A

(40 + 5) – (10 + 15) = 45 – 25 = +20

A population has the following values: B = 40, D = 10, I = 5, E = 15. What is the net change in population size?
A. +20
B. +30
C. +10
D. 0

B

Population size decreases when:
A. Births + immigration > deaths + emigration
B. Deaths + emigration > births + immigration
C. Immigration > emigration
D. Births > deaths

D

Exponential growth assumes:
A. Limited food resources
B. High competition
C. No immigration or emigration
D. Unlimited resources and constant r-max

B

Logistic growth differs from exponential growth because logistic growth:
A. Occurs only in animals, not plants
B. Levels off when the population reaches carrying capacity
C. Has a constant growth rate regardless of resource availability
D. Cannot occur in nature

B

On a logistic curve, population growth slows because:
A. Birth rates increase
B. Resources become limited
C. Predators disappear
D. Immigration increases

B

r-max is defined as:
A. The number of individuals at carrying capacity
B. The maximum per-individual growth rate under ideal conditions
C. The number of deaths per generation
D. The total number of births minus deaths

C

Two exponential curves are shown. Curve A is steeper than Curve B. Which statement is correct?
A. Curve A has the lower r-max
B. Curve B has the higher r-max
C. Curve A has the higher r-max
D. Both curves have the same r-max

C

Which of the following is a density-dependent factor?
A. Hurricane
B. Harsh winter
C. Disease spreading through a deer population
D. Wildfire

D

Which of the following is a density-independent factor?
A. Competition for food
B. Parasites
C. Predation
D. Severe drought

B

Intraspecific competition occurs when:
A. Different species compete for resources
B. Members of the same species compete for limited resources
C. A population reaches carrying capacity
D. The intrinsic growth rate increases

B

Carrying capacity is best defined as:
A. The number of immigrants a population can support
B. The maximum population size the environment can sustain
C. The amount of available food during winter
D. The average number of births per generation

C

On a population graph, carrying capacity can be estimated by:
A. The lowest point of the curve
B. The point where the population crashes
C. The level where the population stabilizes
D. The initial population size

A

When a population reaches K:
A. Births = deaths
B. Birth rates exceed death rates
C. Deaths are much higher than births
D. Exponential growth continues

C

A population crash is usually caused by:
A. High birth rates
B. Logistic growth
C. Density-independent factors
D. Intraspecific competition only

C

An age structure with a wide base indicates:
A. Stable population size
B. Shrinking population
C. Rapidly growing population
D. Population with high emigration

B

A rectangular age structure (even distribution of ages) indicates:
A. Growing population
B. Stable population
C. Decreasing population
D. Overpopulation

C

A population with a narrow base and more older individuals is:
A. Increasing in size
B. Stable
C. Decreasing
D. Unpredictable

C

Age structure histograms show:
A. Birth and death rates only
B. The number of immigrants and emigrants
C. The distribution of individuals among age groups
D. Seasonal changes in population size

B

Demography is the study of:
A. Predator–prey relationships
B. Human population characteristics
C. Natural selection
D. Gene flow between populations

C

A population graph shows the curve leveling off at ~600 individuals. What is the carrying capacity?
A. 100
B. 300
C. 600
D. 900

C

Which part of the logistic curve shows the fastest growth rate?
A. Lag phase
B. Equilibrium phase
C. Middle section approaching K
D. At carrying capacity

C

A population overshoots its carrying capacity. What is most likely to happen next?
A. Rapid exponential growth
B. Immediate extinction
C. Population crash
D. Birth rate increases drastically

C

Exponential growth curves appear:
A. S-shaped
B. Linear
C. J-shaped
D. Backwards-S-shaped

A

Which graph pattern shows a population undergoing logistic growth?
A. One that rises quickly and levels off
B. One that maintains a constant slope
C. One that rises and never slows
D. One that cycles seasonally