ANATOMY

Detailed explanation-1: -This process involves the replacement of hyaline cartilage with bone. It begins when mesoderm-derived mesenchymal cells differentiate into chondrocytes. Chondrocytes proliferate rapidly and secrete an extracellular matrix to form the cartilage model for bone.

Detailed explanation-2: -Endochondral ossification involves the replacement of hyaline cartilage with bony tissue. Most of the bones of the skeleton are formed in this manner. These bones are called endochondral bones. In this process, the future bones are first formed as hyaline cartilage models.

Detailed explanation-3: -Tubular and flat bones, vertebrae, the skull base, ethmoids, and the ends of the clavicles are formed by endochondral ossification.

Detailed explanation-4: -During endochondral ossification, chondrocytes proliferate, undergo hypertrophy and die; the cartilage extracellular matrix they construct is then invaded by blood vessels, osteoclasts, bone marrow cells and osteoblasts, the last of which deposit bone on remnants of cartilage matrix.

Detailed explanation-5: -Answer and Explanation: The correct answer is option (b) cartilage is replaced by bone. Endochondral ossification is the process of bone formation that uses cartilage as a bone template during fetal development. The cartilage is not turned into bone but systematically replaced by bone to form the body skeleton.