Question

QUESTION 10

1. Bone and cartilage (select the BEST CORRECT statement)

   		Both cartilage and bone have extracellular matrices that are composed of secreted collagen and proteoglycans, along with other substances.
   		Osteoblasts deposit new bone by secreting collagen, proteoglycans, calcium, and phosphate.
   		Hydroxyapatite is an important bone mineral composed of calcium and sulfate.
   		All of the above are correct.
   		Only (a) and (b) are correct

Answer 1

Only (a) and (b) are correct

• Hydroxyapatite is an important bone mineral composed of calcium and phosphate. Hence option C is incorrect.
• Hydroxyapatite is also called hydroxylapatite, is a naturally occurring mineral form of calcium apatite with the formula Ca₅(PO₄)₃, but it is usually written Ca₁₀(PO₄)₆(OH)₂.
• Both cartilage and bone have extracellular matrix , which are composed of secreted collagen, proteoglycan.
• The osteoblasts secrete a collagen-proteoglycan matrix that is able to bind calcium salts.
• Both option A and B are correct , but option C is wrong , hence option D is incorrect.