Question

Dermatogen, periblem, and plerome are
A) Permanent tissues
B) Meristematic tissues
C) Intercalary tissues
D) Secondary tissues

Answer 1

These are the young structural tissues responsible for the primary growth of the plant.

Complete Answer:
Meristematic Tissue consists of the cells which have the ability to divide and redivide to form new cells. Dermatogen, periblem, and plerome are meristematic tissues.
The newly formed cells are similar to the parent cell as they divide by mitosis but as they grow their characteristics change and they differentiate according to their function. On the basis of position, the meristematic tissues can be divided into Apical, Lateral, and Intercalary meristem. Apical meristem is a type of meristematic tissue which is present at the shoot tip and continuously divide to form three layers:-

-Dermatogen: It is the part of the apical meristem that forms the outermost layer of a plant. It forms the epidermis.
-Periblem: It is the part of the apical meristem that is located between the plerome and dermatogen. It is responsible for the formation of the hypodermis, cortex, and endodermis.
-Plerome: It forms the central core of a plant and gives rise to t stele. The stele consists of vascular tissue, pith, and pericycle. The cells of the plerome develop into procambium to form the vascular bundles.

So, the correct answer is ‘Meristematic tissues'.

Note: The activity of the primary meristem is best understood by the ‘Histogen theory' given by Hanstein in 1868. Hanstein collectively called the dermatogen, periblem, and plerome as Histogens. The process by which cells arise from meristematic tissue and finally take up a permanent shape, size, and function is called differentiation.