Define growth, differentiation, development, dedifferentiation, redifferentiation, determinate growth, meristem and growth rate. | NCERT solution | Class 11 Biology | Unit-15 Plant Growth and Development



Q.1:- Define growth, differentiation, development, dedifferentiation, redifferentiation, determinate growth, meristem and growth rate.

 

Answer:- 

Growth: A permanent and irreversible increase in size of an organ or its part or even of an individual cell is called growth.

Differentiation: The process which leads to maturation of cells is called differentiation. During differentiation, a few or major changes happen in protoplasm and cell walls of the cells.

Development: All the changes which an organism goes through during its life cycle become parts of development. In case of a flowering plant, right from seed germination to seed bearing, each stage is a part of the development process.



Dedifferentiation: A differentiated cell can regain its capacity for cell division under certain conditions. This phenomenon is called dedifferentiation. Formation of interfascicular cambium and cork cambium from fully differentiated parenchyma cells is an example of dedifferentiation.

Redifferentiation: A dedifferentiated plant cell once again loses its capacity to divide and becomes mature. This phenomenon is called redifferentiation.

Determinate Growth: When growth stops after a certain phase, this type of growth is called determinate growth.

Meristem: The plant tissue which has the ability to divide is called meristematic tissue. The region with such tissues is called meristem.

Growth Rate: The increased growth per unit time is called growth rate.