Onion root cap and region of cell division
Onion root regions of cell division, elongation, and maturation
Plants are placed into two simple kingdom subsections: nonvascular and vascular plants. The big distinction between the two groups is that vascular plants have vascular_tissues: tissues that conduct water and dissolved food in the plant body. The vascular tissues include xylem, which moves water and minerals upward through the plant and phloem, which moves dissolved food downward in the plant.
Nonvascular plants lack these tubes, and therefore must be small and thin so that each cell can acquire its needed materials via passive_transport from the plant's surface, or from other cells within the plant that are located near the surface.
Regardless of whether a plant is vascular or nonvascular, it has structures that (1) anchor it into the soil, (2) provide physical support for its photosynthetic structures, and (3) specialize in performing photosynthesis. The difference is that in nonvascular plants these structures are called root-like, stem-like, and leaf-like because they lack vascular tissues.
True roots, stems, and leaves are those body structures that contain vascular tissues. The tip of roots and stems have a region of rapid cell_division known as the apical_meristem. The root tip has a layer of cells called the root_cap that helps protect the apical cells from frictional damage as the root pushes into soil. The three regions are:
(1) region_of_cell_division, the area of rapid cell division;
(2) region_of_elongation, where half of the newly divided cells focus on individual growth, and the other half of the newly divided cells remain apical division cells; and
(3) region_of_maturation, where the new cells continue their growth and specialization.