Echinoderms: Water Vascular System — NEET Biology
✅ Asked in NEET 2021These animals have an endoskeleton of calcareous ossicles and, hence, the name Echinodermata (Spiny bodied,). All are marine with organ-system level of organisation. The adult echinoderms are radially symmetrical but larvae are bilaterally symmetrical. They are triploblastic and coelomate animals. Digestive system is complete with mouth on the lower (ventral) side and anus on the upper (dorsal) side. The most distinctive feature of echinoderms is the presence of water vascular system which helps in locomotion, capture and transport of food and respiration. An excretory system is absent. Sexes are separate. Reproduction is sexual. Fertilisation is usually external. Development is indirect with free-swimming larva.
NTA tests students on the unique characteristics of echinoderms, especially the water vascular system that distinguishes them from other phyla. This system functions in locomotion, feeding, and respiration—a triple role students often forget. A common mistake is confusing echinoderms with other coelom animals or thinking their radial symmetry applies to larvae too (larvae are actually bilateral). Remember: adult echinoderms are radially symmetrical, have calcareous ossicles, and lack an excretory system. The water vascular system with tube feet is their defining feature—it's what NTA consistently focuses on because it's unique to this phylum and fundamental to understanding their ecology.
Read the following statements: I. Metagenesis is observed in helminths. II. Echinoderms are triploblastic and coelomate. III. Roundworms have organ system level. IV. Water vascular system is characteristic of echinoderms. Choose the correct answer. NEET Year: NEET 2021
Through deep analysis of NEET and NTA, 88 of 90 questions from the NEET 2026 paper were matched straight from the MedicNEET Biology question bank.
88/90MedicNEET's Biology question bank is built from the same NCERT lines NTA picks repeatedly. Not random MCQs — questions crafted exactly like NTA crafts them.