Symbiosis — Science definition
A close, long-term relationship between two different species, which may benefit both (mutualism), benefit one without affecting the other (commensalism), or benefit one at the other's expense (parasitism).
Where it is taught
- Populations & Communities — Ecosystems & Conservation Decisions, Life Science: Biology, Grade 10
In use
In symbiosis, two species live in close, long-term partnership, and biologists classify these by who comes out ahead.
Populations & Communities
Questions using symbiosis
Problem 1
Answer and explanation
In mutualism both species benefit, as when a pollinator feeds and the plant is pollinated. In commensalism one benefits and the other is largely unaffected, as when a bird nests in a tree. In parasitism one benefits at the other's expense, as when a tapeworm absorbs nutrients from a host. The classification depends on measured effects on survival or reproduction, not on appearances, and the same pair can shift category as conditions change.
Response criteria
- State a biologically accurate conclusion.
- Show the data, mechanism, or calculation that supports it.
- Include units, conditions, or limits where relevant.