Practice question

Diploblastic animals possess only two primary germ layers formed during gastrulation: outer ectoderm giving rise to epidermis and nervous elements, and inner endoderm lining gastrodermis or gastrovascular cavity, with intervening acellular or sparsely cellular mesoglea not true mesoderm producing muscle. Cnidaria and Ctenophora exemplify this architecture, where epitheliomuscular cells derived from ectoderm and endoderm perform contraction, lacking coelom and mesodermally derived organs. Triploblasts add third layer mesoderm generating musculature, circulatory and skeletal tissues enabling complex organogenesis. This concept holds high importance for NEET, CBSE board, CUET and competitive examinations focusing on comparative morphology and evolutionary