Question

The skull of the frog is
(a) Tricondylic
(b) Monocondylic
(c) Dicondylic
(d) Noncondylic
(e) Polycondylic

Answer 1

Hint: It is a skull that is attached to the body by two articulatory condyles. Beneath the foramen magnum (the hole in the base of the skull) of the frog, there are two occipital condyles (round knob at the base of the skull).

Complete answer:
The skull of the frog is dicondylic. On either side of the foramen magnum, dorsolateral (upper and side) exoccipital bones are present.
Additional information:
- As a frog has no ribs, the dicondylic skull is connected to the first vertebral bone of the spine.
- The skull of a frog is broad and flat and consists of a narrow cranium or brain box, paired sense capsules, large orbits, the jaws, hyoid, and cartilages of the larynx.
- In the front part of the cranium of frog, the sphenethmoid (front end bone) encloses the forebrain and olfactory sacs.
- A monocondylic skull contains a single occipital condyle, such as the skull of reptiles.
- The skull of human beings is a dicondylic skull. It has two occipital condyles, with the help of these two condyles skull is connected by the first vertebral column that is the atlas bone.
- In humans, the condyles are oval or reformed (kidney-shaped) . The articular (forming a joint) surfaces of the condyles in humans are convex from before the backward and from side to side and look downward and lateral.

So, the correct answer is, ‘Dicondylic.’

Note: The skull of a frog is divided by a transverse partition into an anterior ethmoidal (separating the nasal cavity from the brain) region and a posterior sphenoidal (middle part of the base) region which encloses the forebrain. The ethmoidal region encloses the olfactory sacs.