The breeding group of pink salmon in a river is an example of which concept?

• A. Population
• B. Species
• C. Community
• D. Ecosystem

Answer: (A)

A population is a group of individuals of the same species living in a defined area. The breeding group of pink salmon in a river fits this idea because it’s all pink salmon (same species) gathering in that specific river environment during the breeding season. This distinguishes it from a species as a whole (all pink salmon anywhere), a community (all species living in the river), or an ecosystem (the community plus the physical environment and their interactions). Focusing on this local breeding group allows study of how many individuals there are, how they reproduce, and how they might be affected by conditions in that particular river.