11th Biology Chapter 13

1. Growth: This is an irreversible permanent increase in size of an organ or its parts. Growth is coupled with metabolic processes and portrayed through physical parameters like height and volume【4:0†source】.

2. Differentiation, Dedifferentiation, and Redifferentiation: Differentiation involves cells undergoing structural changes to perform specific functions. Dedifferentiation is the process where differentiated cells regain cell division capabilities, and Redifferentiation allows these cells to mature into functional states once more【4:4†source】.

3. Development: This encompasses all changes a plant undergoes from seed germination to senescence. It is a combination of growth and differentiation, influenced by both intrinsic and extrinsic factors【4:5†source】.

4. Plant Growth Regulators (PGRs): Chemicals produced by the plant that control various physiological processes. There are both growth-promoting PGRs such as auxins and gibberellins, and growth-inhibiting PGRs like abscisic acid and ethylene which respond to environmental stresses and induce dormancy【4:6†source】.