How do meristems make plants grow throughout their lives?

Plants are able to grow throughout their entire life span due to the presence of meristems, which are regions of undifferentiated, actively dividing cells. Unlike most animals, which have a determinate growth pattern, plants maintain these "permanently embryonic" tissues to continuously produce new cells.1234

Meristems facilitate growth through two primary mechanisms:

• Cell Division: Within a meristem, specialized cells called initials undergo mitosis. When an initial divides, one daughter cell remains in the meristem to ensure a continuous supply of new cells, while the other is displaced into the plant body to differentiate into specific tissues.34
• Differentiation: These displaced cells eventually mature into the various tissues required for the plant's structure and function, such as the epidermis, vascular tissues, and ground tissues.13

Growth is further categorized by the type of meristem involved:
* Apical meristems are located at the tips of roots and shoots and are responsible for primary growth, which increases the length of the plant.123
* Lateral meristems, such as the vascular cambium and cork cambium, facilitate secondary growth, increasing the girth and thickness of stems and roots.134