Echinoderm Symmetry Changes — NEET Biology
✅ Asked in NEET 2026Select the incorrect statements: A. Digestive system in Platyhelminthes is incomplete. B. Bilateral symmetry is a characteristic of adult Echinoderms. C. Pseudocoelom in Aschelminthes. D. Notochord persists throughout life in Chondrichthyes. E. Reptiles maintain a constant body temperature.
Select the incorrect statements: A. Digestive system in Platyhelminthes is incomplete. B. Bilateral symmetry is a characteristic of adult Echinoderms. C. Pseudocoelom in Aschelminthes. D. Notochord persists throughout life in Chondrichthyes. E. Reptiles maintain a constant body temperature.
Answer & NCERT explanation
Correct answer: B — B and E only
Adult echinoderms have radial symmetry, not bilateral (B wrong). Reptiles are poikilotherms (cold-blooded) and cannot maintain a constant body temperature (E wrong). Other statements are correct.
Read more NCERT concept on the PYQ
*Echinodermata exhibits radial or bilateral symmetry depending on the stage.
Echinoderms show both radial and bilateral symmetry at different life stages—larvae are bilaterally symmetric, while adults display radial symmetry. NTA tests this because it highlights the unique developmental transition in this phylum, distinguishing them from other animal groups. Students often mistake echinoderms as purely radial or assume symmetry is fixed, missing the developmental angle. Remember: bilateral larvae → radial adults. This concept is tested to evaluate understanding of how body plans change during development and to differentiate echinoderms from cnidarians (which are radially symmetric throughout life) and chordates (bilaterally symmetric throughout).
What does NCERT say about Echinodermata exhibits radial or?
Has this concept appeared in NEET?
Which chapter is this from?
Through deep analysis of NEET and NTA, 176 of the 180 ReNEET 2026 (June 21) questions were already in the MedicNEET question bank before the exam.
176/180MedicNEET's Biology question bank is built from the same NCERT lines NTA picks repeatedly. Not random MCQs — questions crafted exactly like NTA crafts them.