5. If you were given an unfamiliar vegetable, how could you tell if it was a root or a stem, based on its external features and a microscopic examination of its cross section

In roots, the vascular tissues, i.e., xylem and phloem, are found in the central vascular cylinder, while in stems these tissues are dispersed throughout the stem, generally arranged as a ring towards the outside of the stem (epidermis)

Explanation:

Vascular plants have two different transport tissues: xylem and phloem. The xylem transports water from roots to stems and leaves, while the phloem transports food (i.e. dissolved sugars) from the leaves to all parts of the plant. In roots, vascular tissues form a central core in order to withstand stretching forces. Moreover, in stems, vascular tissues are dispersed (generally concentrated towards the epidermis), in an arrangement that enables them to resist compression and bending forces.