Question

In Frog, the typical vertebrae are
A. Acoelous
B. Procoelous
C. Amphicoelous
D. Opisthocoelous

Answer 1

Hint: A typical vertebra has a central which implies to an axial cylindrical piece to which various processes are attached. Centrum is responsible for providing strength as well as for attaching one vertebra with the other. In Anura, the caudal region is absent and vertebrae possess convexity on the posterior side whereas the concavity on the anterior side.

Complete answer:
Acoelous vertebrae are flat on both the posterior as well as the anterior ends of the centrum. An example of the Acoelous vertebrae would be the vertebrae present in the human spine.
The amphicoelous vertebrae has a centrum with a concavity on both the ends i.e the posterior and the anterior side. Centrum of Amphicoelous is frequently integrated with a full notochord. Commonly, these vertebrae are found in fishes as the motion is limited in the water.
Frogs are the vertebrates that belong to class amphibia. Procoelous vertebrae are convex on the posterior side while convex at the anterior side. This vertebra is found in modern reptiles and frogs.
Opisthocoelous vertebrae are just the opposite of procoelous i.e the vertebrae possess convexity at the anterior side and concavity at the posterior side. They are present in amphibians like salamanders (urodele) and some non-avian dinosaurs.

Therefore, the correct option is (B) Procoelous.

Note:
The student might get confused between the Procoelous and Amphicoelous because the 8th vertebrae are amphicoelous while from second to seventh vertebrae are procoelous with the transverse elongated processes in the Anura i.e in the frogs of the class amphibia.