Theories of Root Apex MCQ - Practice Questions with Answers

Theories related to Root Apex

• Root apex is represented by the group of initials present sub terminally below the root cap. 
• Root apical meristem is derived from the radicle of the embryo.

1. Calyptrogen Theory: It was proposed by Hastein as the continuation of the Histogen Theory. It suggests that the root apical meristem also has dermatogen, periblem, plerome as well as an additional layer of calyptrogen which gives rise to the root cap.
2. Korper-Kappe theory: It was given by Schuepp in 1917. It is similar to the tunica corpus theory of shoot apical meristem. Korper means body and kappe mean cap.
3. Quiescent centre theory: It was given by Clowes in 1961. He studied maize and proposed that between the root apical meristem and root cap, there is a region of inactive cells called the quiescent centre. These cells have fewer mitochondria, ER, very small nuclei, and a low rate of metabolism. These cells act as a reservoir of meristematic cells. In case of injury to meristem, they become meristematic and add to the growth of the root.