Question

The process of bone formation is known as
A. Ossification
B. Calcification
C. Calcination
D. None of the above

Answer 1

Hint: Bone formation is the process by which new bone is produced. It begins about the third month of fetal life in humans and is completed by late adolescence.

Complete Answer:
- The process of laying down new bone material by cells called osteoblasts is known as ossification or osteogenesis. Osteoblasts secrete a matrix material called osteoid that is a gelatinous substance made up of collagen, a fibrous protein, and mucopolysaccharide, an organic glue.
- Once the osteoid is laid down, inorganic salts are deposited in it to form the hardened material known as mineralized bone. The cartilage cells die out and are replaced by osteoblasts gathered in ossification centres.

 The process of bone formation occurring at different time intervals are as follows:
- Third month of fetal development: Bone formation begins.
- Fourth month: The primary bone forming centers appear in the diaphysis of bone.
- Birth to 5 years: Secondary ossification (bone formation) centers occur in the epiphyses.
- 5 to 12 years in females and 5 to 14 in males: Ossification spreads from the ossification centers and various bones start becoming ossified (solidify).
- 17 to 20 years: Bone of the upper limbs and scapulae become completely ossified.
- 18 to 23 years: The lower limb and hip bones become completely ossified.
- 23 to 26 years: Bones of sternum, clavicles, and vertebrae become completely ossified.
- By 25 years: Mostly all bones are completely ossified.
- Calcification is the process by which calcium ions are accumulated in the body tissue. Calcination is the process when heating is done under high temperature in the presence of air.

Hence, the correct option is A, ‘Ossification’.

Note: The immature bone undergoes a process of bone resorption and deposition called bone remodeling to produce the mature bone.