Question

Periderm includes:

• A. Cork and secondary cortex
• B. Only cork cambium
• C. Cork cambium and cork only
• D. Cork cambium, phellem and secondary cortex

Answer 1

The correct option is D Cork cambium, phellem and secondary cortex

Phellogen, phellem, and phelloderm are collectively known as periderm.
Phellogen or the cork cambium 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. The cells of secondary cortex are parenchymatous.