Question

Where do dermatogen, periblem and plerome occur?

• A. Secondary meristem
• B. Apical meristem
• C. Lateral meristem
• D. Permanent tissues

Answer 1

Answer: (B)

Apical meristem

• The shoot apical meristem present at the shoot tip continuously divide to form three layers:-

1) Dermatogen is the primary meristem that forms the outer most layer of a plant or a plant part and forms the epidermis.

2) Periblem is a primary meristem which is located between the plerome and the dermatogen and it forms the cortex.

3) Plerome is the primary meristem that forms the central core of a plant or plant part which gives rise to the stele (includes the vascular tissue, pith and pericycle).

• The part of plerome from which vascular tissues are formed is called procambium.
  
• All these layers are located at the shoot tip in plants as these are derived from the apical meristematic tissues according to the histogen theory given by Hanstein.
  
• So, the correct answer is 'Apical meristem'