Which term best describes the variety and relative abundance of species within a community?

• A. Keystone species
• B. Biodiversity
• C. Trophic level
• D. Primary productivity

Answer: (B)

Biodiversity describes the variety and relative abundance of species within a community. It captures both how many different species are present (richness) and how evenly individuals are distributed among those species (evenness). A community with many species and a balanced distribution has high biodiversity, which supports robust ecosystem functions like nutrient cycling and resilience to change.

Keystone species refer to a species that has a disproportionately large effect on the environment relative to its abundance, not to overall variety or abundance. Trophic level is about a species’ position in the food chain, not how many species there are or how their populations are distributed. Primary productivity measures the rate at which biomass is produced, not how diverse the community is.