Final answer:
The centriole in the sperm neck generates the axoneme of the flagellum for sperm motility and forms the basal body for structural support and anchorage of the flagellum.
Step-by-step explanation:
The centriole in the sperm neck has two main functions. First, it generates the axoneme of the flagellum, which is essential for the motility of the sperm. The axoneme is essentially the structural core of a flagellum, necessary for its whipping motion that propels the sperm cell forward. Second, the centriole forms the basal body, which acts as the foundation from which the flagellum's microtubules grow and anchors the flagellum to the cell body.