Answer: Jointed appendages.
- A Jointed appendages
- B a soft unsegmented body
- C only a radial symmetry
- D the presence of setae
Correct answer: A. Jointed appendages
Explanation: Jointed appendages characterise the arthropods.
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.