GROWTH AT DIFFERENT LEVELS -
1. Molecular level - It involves synthesis of new molecules and their aggregation into organellae.
2. Cellular level - It includes -
(i) Expansion or hypertrophy - Increases in the size of cell due to addition of protoplasm.
(ii) Cell division (Hyper plasin) - Increase in the number of cells.
(iii) Cell differentiation - formation of tissue and organs.
(iv) Matrix formation - addition of apoplasmatic substance as matrix of connective tissue, inercellular fluid.
3. Individual level - Visible increase in body dimension.