PATHOLOGY

Detailed explanation-1: -Endoskeleton. An endoskeleton is a skeleton that consists of hard, mineralized structures located within the soft tissue of organisms. An example of a primitive endoskeletal structure is the spicules of sponges. The bones of vertebrates are composed of tissues, whereas sponges have no true tissues (Figure 19.4).

Detailed explanation-2: -Endoskeleton is an internal skeleton present in the bony or cartilaginous fishes. The cartilaginous fish’s endoskeleton is composed of cartilage. The bony fish’s endoskeleton is mainly of bones. Cartilaginous fish come under the class Chondrichthyes and all bony fish under the class Osteichthyes.

Detailed explanation-3: -Mammals, reptiles, birds, fish and amphibians are vertebrates with endoskeletons (skeletons inside their bodies). Their skeletons provide support and protection and help them to move.