Question

Histogen theory is more applicable for

• A. Root apex
• B. Meristematic tissue
  
• C. Both (A) and (B)
• D. None of the above

Answer 1

Answer: (A)

The histogen theory was given by Hanstein (1870). The three principal tissues of the root vascular cylinder, cortex and epidermis originate from three groups of initial cells or histogens, in the apical meristem plerome, periblem and dermatogen respectively. A fourth histogen, the calyptrogen, produces the root cap.
Thus, the correct answer is option A.