Zaymiey

🔬 Biology  ·  Animal Kingdom  ·  NEET

Which is the largest phylum in the animal kingdom?

Answer: Arthropoda.

  • A Mollusca
  • B Annelida
  • C Arthropoda
  • D Chordata

Correct answer: C. Arthropoda

Explanation: Arthropoda is the largest phylum, comprising more than two-thirds of all named animal species, including insects, crustaceans, and arachnids.

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 →