Answer:
Photosynthesis is not the primary function of stem. It is a function of leaves. Whereas, conduction of water and minerals from roots to other parts, formation of branches, bearing flowers and fruits and holding the plant upright are main functions of a stem.
Step-by-step explanation:
The primary functions of the stem are to support the leaves; to conduct water and minerals to the leaves, where they can be converted into usable products by photosynthesis; and to transport these products from the leaves to other parts of the plant, including the roots.