Question

Which one of the following organism(s) is/are triploblastic?

• A. Corals
• B. Flat worms
• C. Sponges
• D. Ctenophores

Answer 1

The correct option is B Flat worms

Depending on the number of germ layers, the animals have been categorized into the following two types:

1. Diploblastic animals: these animals have two germ layers – outer ectoderm and inner endoderm. EXAMPLES - Sponges, Coelenterates, Ctenophores, etc. Coelenterates and Ctenophores (eg. Ctenoplana, Velamen, Hormiphora, etc.) are traditionally regarded to be diploblastic, but they are sometimes considered to be triploblastic. However, there is controversy regarding that.
2. Triploblastic animals - these animals comprise three germ layers – outer ectoderm, middle mesoderm, and inner endoderm. EXAMPLES - Flatworms, Annelids, Mammals, etc.