What are the sites of rapid cell division in the root tips and cambiums called?

Meristems are the regions in plants where rapid cell division occurs, essential for growth. In root tips, the apical meristem is responsible for increasing the length of roots, allowing the plant to penetrate deeper into the soil for water and nutrients. Similarly, in the cambium layer, which is a type of lateral meristem, cell division contributes to the increase in girth of the stem, facilitating the plant's support as it grows.

Nodes, leaves, and stems do not serve as sites of rapid cell division. Nodes are points on a stem where leaves and branches originate. Leaves are primarily involved in photosynthesis and gas exchange rather than cell division. Stems provide structural support and transport nutrients but do not represent the areas of active cell division like meristems do. Thus, meristems play a critical role in plant growth and development through their ability to continuously produce new cells.