question_answer 39)

  Arrange the following in the sequence you would find them in a plant starting from the periphery-phellem, phellogen, phelloderm.

Answer:

                  Phellogen is a meristematic tissue, while phelloderm is a permanent tissue. Phellogen(cork cambium) develops from the cortical cells, sometimes from pericycle cells. Thesecells actively divide and forms phellem on outer side and phelloderm (cortex cells) innersideon so phelloderm takes its origin from phellogen.