A timber merchant told to the customer that log of wood he is purchasing belongs to $20$ years old tree. He did so by

During the formation of interfascicular cambium, which cells lose the capacity to divide but mature to perform specific function ?

$P -$ protein is found in

$A$ : According to Clowes, there are three histogens in monocot root.

$R$ : In dicot roots, innermost groups of initials form root cap.