The structural material in bone is calcium phosphate.
Bones are made of tissues that include marrow, endosteum, and periosteum, nerves, blood, vessels, and cartilage.

There are more than 300 bones in a new born baby.

I have found a good website which gives information on skeletal system:

How do you lose bones?
You don't lose bones.Your bones combine together as you grow.

What happens if you don't have bones?
If you didn't have bones you'd just be a pile of skin and guts!. Could you walk? no way, Could you stand up? forget about it. Imagine, what would happen if you didn't have

Fun Fact!
Your Skeleton is three times HARDER than concrete!

The Skeletal System contains 206 bones.The Skeletal System is made of bones that hold the body up and protect the vital organs of your bodys other systems.