Question

Pubis in the frog's pelvic girdle is a
(a) Calcified cartilage
(b) Cartilaginous bone
(c) Bone
(d) None of the above

Answer 1

Hint: There are three sections of the hip bone, including ilium, ischium, and pubis, in the frog. However, the pubic elements remain largely cartilaginous. In pubis, calcium salts are deposited in the matrix and this process usually occurs during the growth of bone due to aging.

Complete answer:
The pubis is a paired bone that forms the hip bone anterior portion, and the obturator foramen anterior and lower boundary. At the symphysis of the pubic the left and right pubic bones touch.
The pubis is a triangular hyaline layer, and the calcified cartilage on the ventral side of the pelvic girdle is in older frogs. It is initially hyaline but is later calcified because calcium salts are incorporated in the matrix.

So, the correct answer is, 'Calcified cartilage'.

Additional Information:
There are significant differences in the amphibians in the shape of the pelvic girdle. The hip or pelvic girdle lies in the back of the body to which the pelvic fins or hind limbs are connected. The hip bone is defined by the ilium's great length and forward extension. The girdle is attached to one of the vertebra's costal elements and thus creates a sacral area of the vertebral column. At the intersection of the three components lies the acetabulum (the cup-shaped structure in which the femur articulates).

Note: The pelvic girdle is closely connected to the sacral portion of the vertebral column. Two similar halves of the pelvic girdle are known as 'Ossa innominata.' The pubic bone consists of three parts such as pubis body, lower ramus, and upper ramus.