What term describes the relationship where one organism benefits while the other is not harmed?

The correct term that describes the relationship where one organism benefits while the other is not harmed is commensalism. In this type of interaction, one species gains an advantage or benefit, such as food or shelter, while the other species remains unaffected by the relationship.

For example, in nature, many barnacles attach themselves to whales. The barnacles benefit from being in nutrient-rich waters when the whale swims, while the whale experiences no significant effects from carrying the barnacles. This highlights the key aspect of commensalism: the benefitting organism gains something valuable without impacting the other organism negatively.

Understanding this relationship helps differentiate it from mutualism, where both organisms benefit, and parasitism, where one benefits at the expense of the other, leading to harm or detriment. Similarly, predation involves one organism benefiting by consuming another, which is not the case in commensalism.