Revision: Plant Physiology >> Plant Growth and Development Biology Science (English Medium) Class 11 CBSE

Growth is characterised as an essential process that results in permanent and irreversible changes to the shape, size, form, weight, and volume of a cell, organ, or entire organism, along with an increase in dry matter.

The process by which differentiated cells, which under particular conditions have lost their ability to divide, become meristematic and regain their divisibility is known as dedifferentiation.

Growth that is constrained is referred to as determined growth. For instance, after an animal or plant reaches maturity, its leaves cease to expand.

Meristem is a tissue consisting of unspecialised immature cells, possessing the power of continuous cell division and adding new cells to the body.

The cells derived from root apical and shoot-apical meristems and cambium differentiate and mature to perform specific functions. This act leading to maturation is termed as differentiation.

• Redifferentiation is the process by which dedifferentiated cells mature or differentiate into cells that are unable to divide.
• Examples of these cells are cork cells and secondary xylem components, which are created by redifferentiating secondary cambial cells.

In the life history of a cell, organ, or organism, development can be defined as a process that involves growth, differentiation, and maturation in a predictable sequence, such as seed germination, growth differentiation, flowering, seed production, and senescence. 

The direction of the response is related to the direction from which the stimulus comes. Such a response is known as tropism.

The term "tropic" comes from a Greek word "tropos" which means to "turn'.

Growth movements occurring in response to unidirectional external stimuli in a plant part are called tropic movements.