Explain meristems role in primary and secondary stem growth.?

Question

Explain meristems role in primary and secondary stem growth.?

Answer 1

Meristematic tissue is the tissue in plants that is mitotically active.  All plants have meristematic tissue that allows them to exhibit primary growth (upward, vertical growth).  Often this is the apical meristem located at the tips of the plant stems.  (But not always.  Some plants, like grasses, have there meristematic tissue at the base.  That's why when you cut the grass, it still grows from the bottom.)

Some plants, like woody plants, also have secondary growth that increases the diameter of the plant.  These have lateral meristems that add girth as the plant grows.  In trees these are called cambium layers that add new cork cells, xylem, and phloem.