NEETBotanyAnimal Kingdom
Which of the following is a characteristic of diploblastic animals?
Options
- APresence of an undifferentiated layer between the ectoderm and endoderm
- BAbsence of a mesoderm layer
- CPresence of a single embryonic layer
- DAbsence of a mesoglea layer
Correct answer
A. Presence of an undifferentiated layer between the ectoderm and endoderm
Step-by-step solution
Animals can be categorised on the basis of their symmetry. Sponges are mostly asymmetrical, i.e., any plane that passes through the centre does not divide them into equal halves. When any plane passing through the central axis of the body divides the organism into two identical halves, it is called radial symmetry. Coelenterates, ctenophores and echinoderms have this kind of body plan. Animals like annelids, arthropods, etc., where the body can be divided into identical left and right halves in only one plane, exhi