Practice question

Nematodes belonging to Phylum Aschelminthes are pseudocoelomates possessing persistent blastocoel not fully lined by mesothelium, bounded externally by mesodermal longitudinal muscle layer and internally by intestinal basal lamina of endodermal origin, thus partial peritoneal investment. Unsegmented cylindrical body covered by thick collagenous cuticle requiring ecdysis via ecdysozoan pathway, longitudinal muscles only enabling whip-like movement, syncytial epidermis. Acoelomates lack cavity entirely, eucoelomates or coelomates have complete mesodermal lining in annelids and vertebrates, hence pseudocoelomate distinguishes aschelminth organization supporting hydrostatic skeleton efficiently.