Question

describe the histogen theory

Answer 1

it was propsed by hanstein ..according to this theory shoot apex consists of following histogens
1-Dermatogen-outermost layer
2-periblem-gives rise to tissues between steke and epidermis
3-plerome-innermost layer

Answer 2

Histogen theory is the theory that says that histogens are the ​three layers of tissues present in apical meristem that give rise to different parts of a plant.​ It was introduced by Johannes von Hanstein in 1868. Dermatogen is the outermost layer that is thought to give rise to epidermis. Periblem is the middle layer that gives rise to cortex. Plerome is the innermost region or core of apical meristem that gives rise to stelar region.