The association of plants and fungi in mycorrhizae illustrates a type of relationship called mutualism.

Here's why:

* Mutualism: A relationship where both organisms involved benefit from the interaction.

* In mycorrhizae:

* Plants receive increased access to water and nutrients (especially phosphorus) from the fungus.

* Fungi receive carbohydrates (sugars) from the plant, which they need for energy.

This symbiotic relationship is essential for many plants and helps them thrive in various environments.