Here's why:

* Apical Meristems: These are specialized tissues found at the tips of roots and shoots. They contain undifferentiated cells, meaning they have not yet developed into specific tissue types.

* Cell Division: Apical meristems continuously divide, producing new cells that can then differentiate into the various tissues needed for plant growth.

* Growth and Development: This continuous cell division and differentiation from the apical meristems allows plants to grow in length (primary growth) and develop specialized structures like leaves, stems, roots, and flowers.

Think of the apical meristems as the "growth factories" of a plant, constantly churning out new cells that will form all the different tissues that make up a plant.