Which term describes a predator that removes the competitive dominant and increases community diversity?

• A. Keystone predator
• B. Keystone species
• C. Competitive exclusion
• D. Biological magnification

Answer: (A)

Predators that regulate community structure by keeping a competitive dominant in check can boost biodiversity. When a single species would otherwise monopolize resources, a predator that targets that dominant competitor reduces its advantage, allowing many species to persist and increasing overall diversity. That specific role is captured by the term keystone predator—a kind of keystone species whose impact on the ecosystem comes from predation.

Keystone species is broader and includes non-predator examples of organisms that shape communities, but the description here points to a predator whose activity directly maintains diversity. Competitive exclusion explains why dominance can occur because two species compete for the same niche, but it doesn’t name a predator or its ecological role. Biological magnification refers to toxins accumulating up the food chain, which isn’t relevant to this scenario.