Answer: Echinodermata.
- A Mollusca
- B Echinodermata
- C Hemichordata
- D Annelida
Correct answer: B. Echinodermata
Explanation: The water vascular system, ending in tube feet, is a unique feature of Echinodermata, used for locomotion, capturing food, and respiration.
Moving across the animal phyla, body organisation becomes progressively more complex: from no symmetry and cellular organisation (Porifera) through radial/diploblastic (Cnidaria), bilateral/acoelomate (Platyhelminthes), pseudocoelomate (Nematoda), to a true coelom with full organ systems (Annelida and beyond).
Concept context
Phylum-level classification of the animal kingdom from Porifera to Chordata, based on body symmetry, coelom, and segmentation. One of the most example-heavy chapters for NEET.