Differentiation, Dedifferentiation and Redifferentiation Questions in English

(B) Redifferentiation is the process where cells that have already differentiated lose their ability to divide and become mature tissues to perform specific functions.
$1$. Cork (Phellem): Formed by the activity of cork cambium (redifferentiation).
$2$. Secondary cortex (Phelloderm): Formed by the activity of cork cambium (redifferentiation).
$3$. Cork cambium (Phellogen): Formed by dedifferentiation of cortical cells.
$4$. Vascular cambium: Formed by dedifferentiation of parenchyma cells.
$5$. Secondary medullary rays: Formed by the activity of vascular cambium (redifferentiation).
The tissues formed due to redifferentiation are Cork,Secondary cortex,and Secondary medullary rays.
Therefore,the total number of tissues formed by redifferentiation is $3$.

(C) In plant development,the process begins with cell division (meristematic activity),which increases the number of cells.
Following this,the cells undergo elongation and maturation,eventually leading to differentiation,where they acquire specific structures and functions.
Finally,the cells undergo senescence and death.
In the provided diagram,$P$ represents the phase of cell division (meristematic activity) and $Q$ represents the phase of differentiation.
Therefore,the correct sequence is Cell division and Differentiation.

(B) In plant tissue culture,the process where mature,differentiated parenchyma cells regain the capacity to divide mitotically is known as $Dedifferentiation$.
This process leads to the formation of a mass of undifferentiated cells called $Callus$.
$Differentiation$ is the process where cells undergo structural changes to mature into specialized cells.
$Redifferentiation$ is the process where dedifferentiated cells (like those in the callus) undergo further changes to become specialized again.
Therefore,the correct phenomenon is $Dedifferentiation$.

(C) In tissue culture experiments, leaf mesophyll cells are put in a culture medium to form callus. This phenomenon is called $Dedifferentiation$.
$Dedifferentiation$ is a biological phenomenon by which living differentiated plant cells, which have lost the capacity to divide, regain the capacity of division under certain experimental conditions.

(B) The phenomenon where fully differentiated parenchyma cells regain the capacity to divide and form interfascicular cambium is known as dedifferentiation.
This process allows mature cells to return to a meristematic state to facilitate secondary growth.