Final answer:
The segments of an adult cestode or tapeworm are called proglottids, which contain reproductive structures and detach when mature to continue the life cycle.
Step-by-step explanation:
The body of an adult cestode, or tapeworm, consists of segments called proglottids. These segments are produced at the anterior end of the tapeworm, which is called a scolex, and each proglottid contains reproductive structures. As new proglottids form, they are pushed towards the end of the tapeworm. When they are "mature", all structures except fertilized eggs have degenerated, and these proglottids detach from the worm and are released into the feces of the host. The fertilized eggs within them are then ingested by an intermediate host. The life cycle of tapeworms includes a stage where the juvenile worms emerge in the intermediate hosts and infect their muscle tissue. When this muscle tissue is consumed by the primary host, this completes the life cycle of the tapeworm.