Question

Histogen theory was proposed by

• A. Nageli
• B. Schmidt
• C. Hanstein
• D. Wolf

Answer 1

The correct option is C Hanstein

• The shoot apical meristems located at the shoot tip in plants are derived from the apical meristematic tissues according to the histogen theory given by Hanstein in 1868.
• It consists of three distinct 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.
  

So, the correct answer is 'Hanstein'