EVERYDAY SCIENCE

Detailed explanation-1: -Some of a baby’s bones are made entirely of a special material called cartilage (say: KAR-tel-ij). Other bones in a baby are partly made of cartilage. This cartilage is soft and flexible. During childhood, as you are growing, the cartilage grows and is slowly replaced by bone, with help from calcium.

Detailed explanation-2: -Even so, at birth, many of your baby’s bones are made entirely of cartilage, a type of connective tissue that is tough, but flexible. Some of your little one’s bones are partly made of cartilage to help keep baby nice and, well, malleable.

Detailed explanation-3: -At birth, the skeleton is partially formed. Many bones are still in “parts.” The ends (epiphyses) and bony shafts (diaphyses) of long bones form separately in the womb. At birth, the ends of the long bones are mainly cartilage, with centers of bone beginning to form inside.

Detailed explanation-4: -According to kidshealth.org, humans have 206 bones by the time they’re 25. They are born with about 300 bones and cartilage that, over time, “fuses” together to form the mature adult body.

Detailed explanation-5: -The skeletal components of the vertebral column, the pelvis, and the limbs are first formed of cartilage and later become bone. The replacement of chondrocytes by bone cells is dependent on the mineralization of the extracellular matrix.