Question

Periderm is produced by
a. Vascular cambium
b. Fascicular cambium
c. Phellogen
d. Intrafascicular cambium

Answer 1

The plant tissues include vascular tissues, dermal tissue cells and ground tissue cells. Dermal tissues are associated with the outer and inner layers. The primary growth and secondary growth forms many types of tissues. During secondary growth, phellogen, phelloderm and phellem are formed. Periderm is the outer layer of certain plants.

Complete answer:
The periderm is formed towards the surface of stems or roots. It is the component of secondary growth. Phellogen or cork cambium develops in the subepidermal layer in the stem. It forms the Pericycle in roots, its cells undergo bipolar division.

The phellogen helps to form periderm. It forms the phellem on the outer face and phelloderm on the inner side. The periderm mainly consists of three layers: phellem, phellogen and phelloderm.

The cortical layer and the outer epidermal layer are broken because of the cambium, it occurs during secondary growth. Phellogen is formed by the living parenchyma cells; meristem cells give rise to the periderm, phellem (cork) dead at maturity. The air filled protective tissues are found on the outside.

The main growth tissues in the stems and roots of many plants especially in dicots is called vascular cambium. Fascicular cambium is present between xylem and phloem. It is also called intrafascicular cambium. They are present inside the vascular bundle.

Hence, the correct answer is option (C).

Note: The surfaces of stems and roots of perennial plants covered by the cylindrical tissues or periderm. Periderm is not found in the monocots. It is only found in the gymnosperms and eu-dicots that show secondary growth. The spongy openings are present in the perimeter called as lenticels which allow the gas diffusion into and out of the stem or root.