122 BIOLOGY AND HUMAN LIFE 



Veins (fibrovascular bundles) 



Fibers (mechanical support) 



Vessels (conduction) 



Bringing water and salts to chlorophyl cells 



Taking away finished food 



The root 



General character 



Origin 



Primary Secondary 



From hypocotyl From other roots 



From stem 1 , 



T^ , r f- adventitious 



From leaf J 



Different forms 



Taproots Prop roots 



Fibrous roots Climbing roots 



Fascicled roots Aerial roots 



Structure 



Epidermis 



Root hairs 



Rootcap 



Cortex 



Pith and central cylinder, including fibers 



Vessels 



Conveying water and salts toward stem and leaf (xylem) 



Bringing finished food toward growing region (phloem) 



Growing regions 



Cambium layer ; growing point 



Functions 



Anchorage (holdfasts) (Storage of reserve food) 



Absorption of water and salts (Climbing) 



(Propagation) 



The stem 



General character 



Origin 



Primary 



From epicotyl 



Secondary 



From other stems 



From root "] 



From leaf l-adventitious 



From injured stem J 



