Question

Difference between phellogen and phelloderm and phellum?

Answer 1

Phellogen is a couple of layers thick. It is made of narrow, thin-walled and nearly rectangular cells. Phellogen cuts off cells on both sides. The outer cells differentiate into cork or phellem while the inner cells differentiate into secondary cortex or phelloderm.

Phellogen is defined as the meristematic cell layer responsible for the development of the periderm. ... phelloderm – inside of cork cambium; composed of living parenchyma cells. phellogen (cork cambium) – meristem that gives rise to periderm.

Phellem:

1. Phellem or cork is a tissue formed on the outer side of phellogen or cork cambium.

2. It is composed of dead cells.

3. Phellem is protective in function.

4. The cell walls become impermeable due to suberisation.

5. Phellem cells are filled with tannins.

6. The cells are compactly arranged except for the presence of lenticels.

7. Phellogen is more active on the side of phellem, i.e., more phellem is formed as compared to phelloderm.

8. The outer part of the phellem is peeled off at intervals.



Difference # Phelloderm:

1. Phelloderm or secondary cortex is produced on the inner side of phellogen.

2. Phelloderm is made of living cells.

3. Its cells take part in storage of food.

4. Suberisation is absent.

5. Tannins are absent.

6. The cells enclose small intercellular spaces.

7. Phellogen is less active on the side of phelloderm, i.e., less phelloderm is formed as compared to phellem.