Final answer:
A Salter-Harris type I fracture affects the epiphyseal plate (growth plate) of a bone.
Step-by-step explanation:
A Salter-Harris type I fracture affects the epiphyseal plate (growth plate) of a bone. This type of fracture occurs when there is a separation between the bone and the growth plate. It is commonly seen in children and adolescents whose bones are still growing. The epiphyseal plate is responsible for the longitudinal growth of bones, so a fracture in this area can potentially affect the normal growth and development of the bone.