Botany · Ch 9 — Tissue and Tissue System
Meristematic Tissue
Meristematic Tissue
A tissue is simply a team of cells that share a common origin, a common structure and a common job - the moment cells stop acting individually and start cooperating this way, histology (the study of tissues) has something to study. Every plant tissue belongs to one of two broad camps. Meristematic tissues are the plant's growth engines: their cells stay isodiametric (oval, round or polygonal), pack a dense cytoplasm around a prominent nucleus, keep their vacuoles small or absent, and hold a thin, elastic, cellulose wall - all features that make repeated, rapid division easy. Because a meristematic cell that divides produces one daughter that keeps dividing and one that eventually matures, meristems are described as self-perpetuating; they never run out. Permanent tissues, by contrast, are what those daughter cells become once they stop dividing and settle into a fixed shape suited to a specific job - support, storage, conduction or protection. The whole of the rest of this chapter is really just an expa …
What this figure shows. A young dicot plant body with its three position-based meristem types marked: apical meristem at the tip of the root and at the tip of the shoot (the two growing points responsible for increase in length), intercalary meristem as a band at the base of an internode or leaf (left behind by the shoot apex, between mature tissues), and lateral meristem as a cylinder running along the length of the stem and root (the vascular cambium and cork cambium responsible for gi …