Final answer:
A baby's back plate consists of 33 bones called vertebrae, which make up the vertebral column. Growth plates in baby's bones allow for growth, but they close and bones stop growing as the child reaches adulthood.
Step-by-step explanation:
A baby's back plate consists of 33 bones. These bones are called vertebrae, and they make up the vertebral column (or spine). The vertebral column provides support and protection for the spinal cord, and it allows for flexibility and movement.
The growth plates present in a baby's bones are responsible for allowing the bones to grow longer as the child grows. However, once the child reaches a certain age (typically between 18 to 25 years old), the growth plates close, and the bones stop growing any longer.