Question Detail
Question
Most animals in their embryonic stages are triploblastic except:
Correct Answer
Option C is the correct answer.
Detailed Explanation
Triploblastic animals have three embryonic germ layers (ectoderm, mesoderm, endoderm). Echinoderms, mammals, and aves (birds) are all triploblastic. Porifera (sponges) are either considered diploblastic (having two germ layers, ectoderm and endoderm) or parazoans (lacking true tissues and therefore distinct germ layers), making them an exception to the triploblastic majority.
Hint
Which of these phyla represents the simplest body plan regarding germ layers?