parenchyma cells are relatively unspecialize and thin-walled cells that retain the ability to divide ;
they perform most of the metabolic functions of synthesis and storage.
Collenchyma cells have unevenly thickened walls ; they support young, growing parts of the plant.
Sclerenchyma cells-sclereids and fibers-have thick , lignified walls that help support mature , nongrowing parts of the plant . Tracheids and vassel elements, the water conducting ce;;s of xylem , have thick walls and are dead at functional maturity. sieve-tube elements are living but highly modified cells that are largely devoid of internal organeless ; they function in the transport of suga through the phloem of angiosperm