Final answer:
The epiphyseal plate is the area of growth in a long bone. It allows for bone lengthening by cartilage growth and ossification. It is composed of four zones of cells and activity.
Step-by-step explanation:
The epiphyseal plate is the area of growth in a long bone. It is a layer of hyaline cartilage where ossification occurs in immature bones. On the epiphyseal side of the epiphyseal plate, cartilage is formed. On the diaphyseal side, cartilage is ossified, and the diaphysis grows in length. The epiphyseal plate is composed of four zones of cells and activity.