While comparing invertebrate groups, a developing embryo forms ectoderm, mesoderm, and endoderm. The feature being tested is:

Correct Answer: B

triploblastic organization

Triploblastic animals have three primary germ layers: ectoderm, mesoderm, and endoderm. The mesoderm supports more complex tissues, muscles, and organ systems than are possible in diploblastic animals. This MCQ belongs to the Germ layers topic in Animal Diversity-I and is written to test concept understanding rather than memorized wording.