Final answer:
Radial growth is a biological concept where growth moves from the center toward the outside, influenced by lateral meristems in plants.
Step-by-step explanation:
Growth and development that moves from the center toward the outside is known as radial growth. This growth pattern is associated with the activity of the lateral meristems in plants, which allow for an increase in the girth of roots and shoots. Development in both plants and animals can involve differentiation, where unspecialized cells become specialized in structure and function. This is particularly visible in the organizational growth of a root, where cells transition from the meristematic region near the tip to more mature cells, indicating developmental changes as you move proximally towards the plant body. Cities following a Spanish model of expansion exhibit a similar outward growth, where development extends from a well-established center to newer outer regions.