Answer: Warm-blooded body.
- A Warm-blooded body
- B a cold-blooded system
- C only a scaly cover
- D the moist soft skin
Correct answer: A. Warm-blooded body
Explanation: Birds are warm-blooded (endothermic) animals.
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.