Question

What are the important characteristics of growth? Describe in brief.

Answer 1

Growth can be defined as an irreversible, permanent increase in size of an organ or its parts or even of an individual cell due to synthesis of intracellular and extracellular materials. Growth is generally accompanied by metabolic processes (both anabolic and catabolic). Growth in plants is unique because plants have the capacity of unlimited growth throughout their life. Growth can be measured by a variety of parameters : increase in fresh weight, dry weight, length, volume, area and cell number. The very essential elements for growth are water, oxygen and nutrients.

Growth in plants occurs by cell division and cell enlargement, followed by cell differentiation or cell maturation. Growth in plants is unique because plants have the capacity of unlimited growth throughout their life due to the presence of meristems at certain locations. A plant has four kinds of meristems: the apical meristem and three kinds of lateral—vascular cambium, cork cambium, and intercalary meristem. Apical meristem consist of two important growing points present in the root apex and stem apex. Growth due to apical meristems is called primary growth and leads to the formation of tissues of a plant, increase in the length of the plant and the differentiation of various parts. Intercalary meristems cause increase in length in certain kinds of plants like bamboo, mint, etc. Lateral meristem is responsible for the thickness of the plant in girth. This is called secondary growth. Here meristematic cells, in the form of cambium are present in the vascular bundles of root and stem, thus increasing their thickness.