Answer: Urochordata.
- A Cephalochordata
- B Hemichordata
- C Urochordata
- D Cyclostomata
Correct answer: C. Urochordata
Explanation: In Urochordata (e.g. Ascidia) the free-swimming chordate larva changes into a simpler, sedentary adult - retrogressive metamorphosis.
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.