NEET BIOLOGY

Detailed explanation-1: -The following hierarchic levels of spiral organization of skeletal structures are defined: collagen chains, collagen molecules, microfibrils, fibrils, collagen fibers, osteon network and organization of osseous macrostructure responsible for torsion effect in weight bearing.

Detailed explanation-2: -The bone is made up of compact bone, spongy bone, and bone marrow. Compact bone makes up the outer layer of the bone. Spongy bone is found mostly at the ends of bones and contains red marrow. Bone marrow is found in the center of most bones and has many blood vessels.

Detailed explanation-3: -Bone is a specialized connective tissue consisting of cells, fibers and ground substance. Unlike other connective tissues, its extracellular components are mineralized giving it substantial strength and rigidity.

Detailed explanation-4: -The microscopic structural unit of compact bone is called an osteon, or Haversian system. Each osteon is composed of concentric rings of calcified matrix called lamellae (singular = lamella).