Answer: Birds.
- A Reptiles
- B Amphibians
- C Cartilaginous fish
- D Birds
Correct answer: D. Birds
Explanation: Birds have air sacs connected to the lungs that reduce body weight and supplement breathing during flight.
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.