Final answer:
The accessory nerve (cranial nerve XI) is the cranial nerve with a dual origin. The hypoglossal nerve (XII) does not have a dual origin, and it is involved in tongue muscle contractions.
Step-by-step explanation:
The cranial nerve with a dual origin, meaning it originates from both the brain and the spinal cord, is the accessory nerve (cranial nerve XI). In contrast, the hypoglossal nerve (cranial nerve XII) is responsible for the contraction of the muscles of the tongue, but does not have a dual origin as it originates solely within the brain.
The facial nerve is responsible for taste in the anterior part of the oral cavity, as well as for salivary gland control. Regarding the cranial nerves related to taste, the facial and glossopharyngeal nerves convey gustatory sensations and control salivary glands, while the vagus nerve is involved in visceral responses to taste, such as the gag reflex.
Cranial nerves play essential roles in sensory and motor functions of the head and neck, with some providing strictly sensory or motor functions and others combining both.