Final answer:
Tapeworm proglottids contain an elaborate reproductive system, as tapeworms absorb nutrients from their host's digested material and focus on reproduction within each proglottid.
Step-by-step explanation:
The proglottids of a tapeworm contain an elaborate reproductive system. Tapeworms are endoparasites that live within the digestive tract of a vertebrate host. These organisms do not possess a digestive system due to their unique absorption method of nutrients directly from the host's already digested material. Instead, each proglottid is equipped with male and female reproductive structures, allowing them to produce, mature, and eventually release fertilized eggs into the environment via the host's feces to continue their life cycle.