Question

which of these substances make(s) up the major portion of bone? multiple choice proteoglycan aggregates osteoblasts osteocytes hydroxyapatite collagen

Explanation:

Collagen is a major component of bone matrix, providing tensile strength. Proteoglycan aggregates are more associated with cartilage. Osteoblasts are bone - forming cells, not a major substance of bone. Osteocytes are mature bone cells within the bone matrix, not a major substance either. Hydroxyapatite is an important mineral in bone but collagen makes up a large part of the organic portion of bone, which is a significant part overall.

Answer:

E. collagen