Question

The axial endoskeleton of Elasmobranchs is made up of
(a) Cartilage
(b) Ossified cartilage
(c)Bone
(d) Hyaline cartilage

Answer 1

Hint: These are smooth elastic tissue. These are also the structural components of the rib cage, ears, nose, bronchial tubes, and intervertebral discs.

Complete answer:
The axial endoskeleton of Elasmobranchs is made up of cartilage. Cartilage acts as rubber-like padding that covers and protects the ends of long bones at the joints. During early embryonic development the endoskeletal is composed of notochord and cartilage. In most vertebrates the notochord is replaced by the vertebral column and cartilage is replaced by bone in most adults.

Additional Information: -Cartilage is made up of chondrocytes for specialized cells.
-The endoskeleton or internal skeleton develops within the skin or in the deeper body tissues is composed of hard, mineralized tissue that also enables movement by attachment to muscles.
-The main function of the endoskeleton is for support but it also serves as an attachment site for muscle and mechanism for transmitting muscular forces.
- The endoskeleton includes the axial skeleton with a skull or cranium and the vertebral column and the appendicular skeleton which supports the fins.
-The cartilaginous endoskeleton of embryonic elasmobranchs remains or persists into adulthood.
-As in other gnathostomes the cartilaginous endoskeleton is not replaced or supplemented by plates of endochondral bone.
-Hyaline cartilage is translucent cartilage pearl-grey in color, found on many joint surfaces. Most commonly it is found in the ribs, nose, larynx, and trachea.
-Ossified cartilage is the intermediate cartilage between the hyaline cartilage and the bone.
-Bones constitute part of the vertebrate skeleton in animals. It protects the various organs of the body, produces red and white blood cells, stores minerals, provides structure and support for the body.
So, the correct answer is,’Cartilage’.

Note: -The endoskeleton gives shape and support to the body and also protection to the body and provides a means of promotion.
-During early embryonic development the endoskeletal is composed of notochord and cartilage.
-The cartilaginous endoskeleton of embryonic elasmobranchs persists into adulthood and it is not replaced or supplemented by plates of endochondral bone as in other Gnathostomes.