Final answer:
Incisors and canines typically have one root each, whereas premolars can have one or two roots, with the first premolars usually having two roots and the second premolars one root.
Step-by-step explanation:
The human dentition consists of several types of teeth that have different numbers of roots. Incisors are the sharp front teeth that we use for biting into food and generally have one single root. The canines, also known as cuspids, flank the incisors and are used for tearing food. Canines also typically have one single root. Moving posterior from the cuspids, we find the premolars (or bicuspids), which are used for mashing food due to their overall flatter shape with two rounded cusps. Premolars generally have one or two roots, depending on their position in the mouth. Normally, the first premolars tend to have two roots while the second premolars tend to have one. In summary, incisors and canines usually have one root, whereas premolars can have one or two roots.