Which type of symbiotic relationship benefits one organism and harms the other?

The symbiotic relationship where one organism benefits while the other is harmed is known as parasitism. In this interaction, the parasite derives nutrients or benefits from its host, which suffers harm as a result of the relationship. This harm can manifest in various ways, such as loss of energy, nutritional deficiencies, or even death of the host, depending on the nature and extent of the parasitic relationship.

For example, ticks feed on the blood of mammals, benefiting by obtaining the nutrients they need to survive, while the host suffers from blood loss, potential infections, or disease transmission caused by the tick. This dynamic is what distinctly characterizes parasitism, emphasizing the imbalance of benefit experienced by the two organisms involved.

In contrast, mutualism involves both organisms benefiting, while commensalism describes a relationship where one organism benefits and the other is neither helped nor harmed. Competition refers to the struggle between organisms for limited resources, which does not fit the criteria of a symbiotic relationship where one party is directly benefiting at the expense of the other.