Final answer:
The leaf-cutter ant-fungus relationship is a service mutualism where ants provide leaves for fungi to digest, and in return, the fungi become a food source for the ants.
Step-by-step explanation:
The leaf-cutter ant-fungus mutualism can be described as a service mutualism.
In the relationship between leaf-cutter ants and fungi, both parties provide a service to one another. Leaf-cutter ants cut leaves and bring them to their nests to cultivate fungi, which they cannot digest on their own. The cultivated fungi break down the cellulose in the leaves, producing smaller sugar molecules that they consume. Ultimately, these fungi provide a vital food source for the ants. This mutualism is essential as it allows leaf-cutter ants to overcome the defense mechanisms of plants by utilizing the fungi's ability to break down what the ants themselves cannot.
Similarly, the fungi benefit from a consistent source of nutrients provided by the ants and protection from competitive species. The ants actively patrol and maintain their fungal gardens, ensuring the survival and propagation of their fungal partners. This symbiotic relationship exemplifies how two species can evolve to provide services to each other, resulting in mutual benefits and a highly efficient system of sustenance.