BIOL 271 MODULE 3 EXAM: ADVANCED
ECOLOGY AND EVOLUTION
1. In the context of population dynamics, which parameter in the logistic growth equation
(dN/dt = rN[(K-N)/K]) represents the dampening effect of intra-specific competition?
A. r
B. N
C. K
D. (K-N)/K
Answer: D
Conceptual Explanation: The term (K-N)/K represents the fraction of the carrying
capacity that is still available for population growth, accounting for the effects of density-
dependent competition.
2. Which life history strategy is most likely to be favored in an environment with high,
unpredictable adult mortality?
A. Early maturation and high reproductive effort
B. Delayed maturation and high parental care
C. Iteroparity with low clutch sizes
,D. Extreme longevity and late senescence
Answer: A
Conceptual Explanation: In unpredictable environments where adults have low survival
probability, selection favors ‘bet-hedging’ or early reproduction to ensure offspring are
produced before the adult dies.
3. According to the Intermediate Disturbance Hypothesis, why is species diversity lowest at
high levels of disturbance?
A. Frequent extinctions prevent colonization and establishment
B. Only r-selected species can tolerate the conditions
C. The environment becomes too stable for niche differentiation
D. Competitive exclusion by dominant species occurs
Answer: A
Conceptual Explanation: High levels of disturbance result in frequent local extinctions,
where only the most resilient or fastest-colonizing species can persist, reducing overall
diversity.
4. In a tri-trophic cascade (Predator-Herbivore-Producer), what is the predicted effect on the
producer biomass if the top predator is removed?
A. Producer biomass decreases
B. Producer biomass increases
, C. Producer biomass remains stable
D. Herbivore population crashes
Answer: A
Conceptual Explanation: Removing the top predator releases herbivores from top-down
control, leading to an increase in herbivore abundance and a subsequent decrease in
producer biomass due to overgrazing.
5. Which mechanism explains the coexistence of species that utilize the same limiting
resource in a heterogeneous environment?
A. Character displacement
B. Competitive exclusion
C. Resource partitioning
D. Mullerian mimicry
Answer: C
Conceptual Explanation: Resource partitioning allows species to coexist by using
different parts of the resource, different timing, or different locations, reducing direct
competition.
6. Which component of the Nitrogen cycle is primarily responsible for converting atmospheric
N2 into ammonia (NH3)?
A. Denitrification
ECOLOGY AND EVOLUTION
1. In the context of population dynamics, which parameter in the logistic growth equation
(dN/dt = rN[(K-N)/K]) represents the dampening effect of intra-specific competition?
A. r
B. N
C. K
D. (K-N)/K
Answer: D
Conceptual Explanation: The term (K-N)/K represents the fraction of the carrying
capacity that is still available for population growth, accounting for the effects of density-
dependent competition.
2. Which life history strategy is most likely to be favored in an environment with high,
unpredictable adult mortality?
A. Early maturation and high reproductive effort
B. Delayed maturation and high parental care
C. Iteroparity with low clutch sizes
,D. Extreme longevity and late senescence
Answer: A
Conceptual Explanation: In unpredictable environments where adults have low survival
probability, selection favors ‘bet-hedging’ or early reproduction to ensure offspring are
produced before the adult dies.
3. According to the Intermediate Disturbance Hypothesis, why is species diversity lowest at
high levels of disturbance?
A. Frequent extinctions prevent colonization and establishment
B. Only r-selected species can tolerate the conditions
C. The environment becomes too stable for niche differentiation
D. Competitive exclusion by dominant species occurs
Answer: A
Conceptual Explanation: High levels of disturbance result in frequent local extinctions,
where only the most resilient or fastest-colonizing species can persist, reducing overall
diversity.
4. In a tri-trophic cascade (Predator-Herbivore-Producer), what is the predicted effect on the
producer biomass if the top predator is removed?
A. Producer biomass decreases
B. Producer biomass increases
, C. Producer biomass remains stable
D. Herbivore population crashes
Answer: A
Conceptual Explanation: Removing the top predator releases herbivores from top-down
control, leading to an increase in herbivore abundance and a subsequent decrease in
producer biomass due to overgrazing.
5. Which mechanism explains the coexistence of species that utilize the same limiting
resource in a heterogeneous environment?
A. Character displacement
B. Competitive exclusion
C. Resource partitioning
D. Mullerian mimicry
Answer: C
Conceptual Explanation: Resource partitioning allows species to coexist by using
different parts of the resource, different timing, or different locations, reducing direct
competition.
6. Which component of the Nitrogen cycle is primarily responsible for converting atmospheric
N2 into ammonia (NH3)?
A. Denitrification
