Answer: Greater biodiversity dilutes pathogen transmission risk by including non-competent hosts (reducing pathogen to effective host contact).
- A Greater species diversity is usually associated with higher overall disease transmission, the reverse of what the dilution effect actually predicts in real ecosystems
- B Greater biodiversity dilutes pathogen transmission risk by including non-competent hosts (reducing pathogen to effective host contact)
- C Pathogens become physically diluted when mixed into a larger body of water, a literal chemical dilution rather than any host-community ecological effect
- D A larger number of available hosts usually results directly in less disease overall, regardless of whether those additional hosts are competent disease reservoirs
Correct answer: B. Greater biodiversity dilutes pathogen transmission risk by including non-competent hosts (reducing pathogen to effective host contact)
Explanation: Dilution effect: high-diversity communities contain many non-competent hosts that dilute pathogen transmission. Biodiversity loss can increase disease risk by removing these diluting species.
Energy pyramid showing a simple food chain (producer to herbivore to carnivore) with energy decreasing roughly tenfold at each trophic level.
Concept context
Ecosystems, food chains, energy flow, nutrient cycles, biodiversity, and conservation.