Question

The periderm includes:
(a)secondary phloem
(b)Cork
(c)Cambium
(d)All of these.

Answer 1

Hint: A group of secondary tissues forming a protective layer which replaces the epidermis of the many plant stems, roots, and other parts; composed of cork cambium, phelloderm, and cork.

Complete answer:
The periderm includes three kinds of tissues called phellem(cork), phelloderm and phellogen(cork cambium). During secondary growth, the phellogen becomes meristematic and produces cork towards the outside and the phelloderm towards the inside. It is composed of thin-walled, narrow and rectangular cells.
Phellogen cuts off cells on its either side. The cells stop toward the surface produced to the phellem or cork. The suberin deposits in its cell membrane make it impervious to water. The inner cells produce to the secondary cortex or phelloderm. The secondary cortex is parenchymatous.
Additional Information:
The periderm refers to the collective term used to signify phellogen, phellem, and phelloderm during a plant stem. Periderm formation in plants mainly occurs to exchange the prevailing epidermis.
Formation of periderm
The formation of periderm occurs during secondary growth. During this process, to exchange the broken outer epidermal layer and therefore the cortical layer, the cells of the cortex turn meristematic. As a result of this, cork cambium or phellogen is made. The phellogen consists of thin-walled, narrow and rectangular cells. Then, the phellogen cuts off cells on either side. The cells of the outer side produce the phellem or cork which thanks to the deposition of suberin in its cell membrane is impervious to water. Similarly, the inner side forms the secondary cortex or phelloderm which is especially parenchymatous in nature.

So, the correct answer is,” All of the above.”

Note: The periderm may be a cylindrical tissue that covers the surfaces of stems and roots of perennial plants during early secondary growth; therefore it's not found in monocots and is confined to those gymnosperms and eudicots that show secondary growth.