Practice question

Tapeworms within class Cestoda exhibit highly specialized body plan for intestinal endoparasitism in vertebrate hosts. Scolex serves as holdfast organ bearing four muscular suckers and, in Cyclophyllidea, retractable rostellum with hooks anchoring firmly to host mucosa resisting peristalsis. Immediately behind lies proliferative neck generating strobila composed of serial proglottids, each containing complete set of hermaphroditic reproductive organs maturing anteroposteriorly becoming gravid containing eggs. Nutrient absorption occurs across syncytial tegument due to absent alimentary canal. Turbellaria free-living, Trematoda leaf-shaped with oral-ventral suckers, Monogenea ectoparasitic; none show true strobilation, making scolex-proglottid chain diagnostic for cestodes in parasitology.