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🔬 Biology  ·  Animal Kingdom  ·  NEET

Octopus and Pila belong to which phylum?

Answer: Mollusca.

  • A Echinodermata
  • B Mollusca
  • C Arthropoda
  • D Hemichordata

Correct answer: B. Mollusca

Explanation: Octopus and Pila are both members of phylum Mollusca, characterized by a soft body with a head, visceral hump, and muscular foot.

Body Plan Progression Across PhylaPoriferaasymmetricalcellular levelCnidariaradial, diploblastictissue levelPlatyhelminthesbilateral, acoelomateorgan levelNematodapseudocoel.Annelida+true coelomorgan systemEach step adds organisational complexity: symmetry → germ layers → coelom type → organ systems

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.

Read the full Animal Kingdom notes →