Which relationship features one organism benefiting with no effect on the other?

The correct answer highlights a specific type of ecological relationship known as commensalism. In this interaction, one organism benefits while the other experiences neither positive nor negative effects. This means that one species derives some advantage, such as food, shelter, or transportation, without harming or helping the second species.

For example, birds like barnacles may attach themselves to the shells of turtles. The barnacles benefit from being elevated in the water, where they can better access nutrients, while the turtle is largely unaffected by their presence.

This is distinct from the other relationships mentioned. Mutualism involves both organisms benefiting, such as bees and flowering plants, where bees get food and plants get pollinated. Parasitism is where one organism benefits at the expense of another, like a tick feeding on a host. Predation implies a relationship where one organism (the predator) benefits by consuming another organism (the prey), which clearly has a negative effect on the prey.

Understanding these relationships is essential for studying ecosystems and the various interactions that maintain ecological balance.