Species diversity Knowledge-Based Practice

Questions

1. 1.

   Which of the following best explains how a keystone predator maintains high species diversity within an ecological community?

   • A) It maximizes the carrying capacity of primary producers by increasing nutrient cycling rates.
   • B) It preys on competitively dominant species, preventing the competitive exclusion of subordinate species.
   • C) It eliminates interspecific competition by establishing distinct spatial boundaries between all consumer populations.
   • D) It stabilizes the physical environment by buffering the habitat against abiotic climatic fluctuations.
2. 2.

   Which of the following factors best explains why tropical communities generally exhibit significantly higher species diversity than temperate or polar communities?

   • A) Tropical regions experience severe, frequent climatic disruptions that continuously open new ecological niches.
   • B) Tropical regions have had longer evolutionary periods without major glaciations, coupled with high solar energy and water availability.
   • C) Tropical environments feature extreme seasonal variations in temperature that encourage broad generalist adaptations.
   • D) Tropical habitats support lower primary productivity, which prevents dominant competitors from monopolizing resources.
3. 3.

   According to the intermediate disturbance hypothesis, under which of the following conditions is species diversity within an ecological community maximized?

   • A) When disturbances occur with high frequency and intensity, allowing only fast-growing pioneer species to survive.
   • B) When disturbances are completely eliminated, enabling superior competitors to reach stable climax equilibrium.
   • C) When disturbances occur at moderate frequencies or intensities, preventing competitive exclusion while allowing multiple successional stages to persist.
   • D) When catastrophic disturbances occur continuously, ensuring that no species can establish a permanent population.
4. 4.

   Which of the following best explains why an ecological community with high species diversity generally exhibits greater stability when subjected to environmental disturbances?

   • A) High diversity ensures that coexisting species share the exact same ecological niche, preventing competitive exclusion.
   • B) High diversity eliminates interspecific competition among autotrophs, accelerating primary succession across the habitat.
   • C) High diversity provides functional redundancy, allowing alternative species to maintain ecosystem processes if certain populations decline.
   • D) High diversity relies exclusively on generalist predators, preventing any trophic interactions among primary consumers.
5. 5.

   Which of the following statements correctly distinguishes between species richness and species evenness when evaluating the species diversity of an ecological community?

   • A) Richness measures the proportion of individuals belonging to each species, whereas evenness measures the total number of distinct species present.
   • B) Richness refers to the total count of different species present, whereas evenness reflects the relative abundance and balance among those species.
   • C) Richness quantifies genetic variation within a single population, whereas evenness accounts for the physical distribution of organisms across trophic levels.
   • D) Richness depends exclusively on primary productivity, whereas evenness is determined entirely by interspecific competition.

Answers and step-by-step solutions appear after you finish the test.