Certified Arborist Practice Exam

What do mycorrhizae fungi attach themselves to in a symbiotic relationship?

1. Leaves

2. Branches

3. Roots

4. Seeds

The correct answer is: Roots

Mycorrhizal fungi form a vital symbiotic relationship primarily with the roots of plants. In this association, the fungi attach themselves to the root system, which facilitates a mutual exchange of nutrients. The mycorrhizae extend the surface area of the roots, allowing for enhanced absorption of water and essential minerals, particularly phosphorus, while the plant provides carbohydrates obtained through photosynthesis to the fungi. This relationship not only benefits the individual plant's growth and health but also enhances soil structure and nutrient cycling in the ecosystem. The association with roots is fundamental in diverse plant species, ranging from trees to grasses, making mycorrhizae crucial for healthy plant development and sustainability in various environments. Other plant parts, such as leaves, branches, or seeds, do not have the same established symbiotic role with mycorrhizal fungi, which emphasizes the unique and essential connection they form with plant roots.