Question

Which one is not formed from Procambium?
A. Xylem
B. Phloem
C. Intrafascicular cambium
D. Interfascicular cambium

Answer 1

Hint: Procambium is a meristematic tissue which gives rise to primary xylem and primary phloem. The cells of Procambium are involved in the production of vascular tissues in mature stems and roots.

Complete answer: Apart from the primary xylem and primary phloem, the vascular cambium and cork cambium also develops from the Procambium. Vascular cambium is the tissue which is responsible for the production of secondary xylem inwards towards the pith and secondary phloem outwards towards the bark. This process occurs in oak, gymnosperms (Pine) and vascular plants.
The cambium present between the primary xylem and primary phloem or vascular bundles is called the Intrafascicular cambium. These bundles are arranged in a ring-like manner around the central pith and are conjoint and open.
There are medullary rays lying between the vascular bundles. When their cells dedifferentiate or become meristematic , they give rise to the new cambium which is called interfascicular cambium.
There are some phytohormones that are involved in the vascular cambial activity such as auxins, ethylene, gibberellins and cytokinins.
Interfascicular cambium is not formed from Procambium.

So the correct answer is option D.

Note: The Intrafascicular and interfascicular cambium are the results of secondary growth. Do not confuse between Procambium and vascular cambium. Procambium is the group of meristematic cells which give rise to vascular cambium.