Answer: Platypus (Ornithorhynchus).
- A Kangaroo, a marsupial that gives birth to underdeveloped young
- B Platypus (Ornithorhynchus)
- C Camel, a placental mammal adapted to arid desert environments
- D Monkey, a placental primate with prolonged gestation
Correct answer: B. Platypus (Ornithorhynchus)
Explanation: Ornithorhynchus (platypus) and Tachyglossus (echidna) are egg-laying mammals (monotremes), an exception to the rule that mammals are viviparous.
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.