Question

Histogen is a

• A. Promeristem derivative destined to produce specific areas
• B. Intercalary meristem meant for forming specific tissue
• C. Derivative of lateral meristem
• D. Secondary meristem specialised to produce specific structures

Answer 1

Answer: (A)

Promeristem derivative destined to produce specific areas

• Promeristem is a group of young meristematic cells in its early embryonic stage from which other meristems are derived.
  
• Apical meristems are derived from promeristem and are present below the promeristem at shoot tip and root tip.
  
• The shoot apical meristem (SAM) consists of three distinct meristematic zones called the histogens.
  
• These histogens are present at the growing tips of a stem or a root.
• These tips consist of three histogens and each of these histogens gives rise to tissues which are different from one another- dermatogen, periblem, plerome (principle tissues)
• The dermatogen or the outer layer gives rise to the epidermis, periblem or middle layer gives rise to the cortex as well as the epidermis, plerome or the inner layer gives rise to vascular tissues.
• So, the correct answer is 'Promeristem derivative destined to produce specific areas'.