Solution:
Phelloderm → Phellogen → Phellem
Phellem or cork is the outermost layer, followed by phellogen (cork cambium) which in turn is followed by phelloderm.
Arrange them in a sequential manner, starting from the center – phellem, phellogen, phelloderm.
Arrange them in a sequential manner, starting from the center – phellem, phellogen, phelloderm.