Question

Examine the photograph of a prepared slide of the root cross section. Notice that the section is circular in outline since it was cut across the root. The vascular tissue of the root is concentrated in a single vascular bundle or stele in the center of the root.
How does this compare to the number of vascular bundles in the stem?

Answer 1

The stem has more things to transport that's why it has more vascular bundles. The roots only get water from the ground and moving nutrients from the soil to transfer it to the stem. Having more vascular bundles helps the stems to transfer things to leaves and other parts of the plants.