Question

a typical human baby is born with around 300 bones, but by the time that baby reaches adulthood, it will have only 206. the explanation for this change lies in the way bones grow and develop. with age, the human skeleton undergoes a process of bone fusion. newborns bones are spongy and give way to pressure because they are made primarily of cartilage. these malleable bones make it easier for a newborn to pass through the narrow birth canal. over time, however, the bones gain more calcium and join together, forming the 206 bones that make up an adults skeletal structure. what is the meaning of fusion as used in the passage?

Explanation:

The passage describes how bones in a human body change from birth to adulthood. It mentions that with age, bones join together, and this process is called bone fusion. So, fusion here means the joining - together of bones.

Answer:

The joining - together of bones.