Answer: Has a disproportionately large effect on community structure relative to its abundance, often maintaining prey diversity.
- A Generally has the single largest body size out of any predator present within the ecosystem during normal conditions
- B Has a disproportionately large effect on community structure relative to its abundance, often maintaining prey diversity
- C Usually and invariably reduces overall species diversity within every community where it is found, as generally observed
- D Affects mainly the size of its own population, with little measurable influence on any other species in typical laboratory settings
Correct answer: B. Has a disproportionately large effect on community structure relative to its abundance, often maintaining prey diversity
Explanation: A keystone predator exerts an influence on community structure disproportionate to its numbers, often by controlling the abundance of a dominant prey or competitor, thereby helping to maintain overall species diversity.
Exponential growth produces an ever-steepening J-curve with no limit, an unrealistic long-term model; logistic growth produces an S-curve that levels off at the carrying capacity K, as growth rate (K−N)/K shrinks to zero once resources are fully used.
Concept context
How organisms interact with abiotic factors and respond to stress, plus population attributes, growth models, and interspecific interactions such as predation, competition, and mutualism.