ISA Certified Arborist Practice Exam

Roots are primarily responsible for absorbing water and nutrients from the soil, which is essential for the survival and growth of the tree. This function is critical because trees rely on these resources for various physiological processes, including growth and the production of energy.

The root system also plays a role in anchoring the tree in the ground, providing stability and support for its structure, enabling it to grow tall and withstand environmental forces such as wind. However, the primary function remains to absorb water and nutrients, which are vital for the tree's overall health and functioning.

Photosynthesis primarily takes place in the leaves, not in the roots, making the role of roots in nutrient acquisition more pertinent to the question. Additionally, while roots can offer some protection against pests indirectly by maintaining tree health, their main function does not involve pest protection. Therefore, the key role of roots in absorbing water and nutrients is what makes this answer the most accurate.