question_answer 21)

  Phellogen and phellem respectively denote (a) cork and cork cambium                                           (b) cork cambium and cork (c) secondary cortex and cork                                    (d) cork and secondary cortex

Answer:

                  (b) Cortical Cells In the dicot stem the cortical cells gets differentiated to give rise toanother meristematic tissue which is called cork cambium or phellogen. On the outerside it forms phellem (cork) and in the inner region it forms secondary cortical cells(phelloderm).