07 Plant Growth and Mineral Nutrition - part 01 - Plant growth

07 Plant Growth and Mineral Nutrition - part 01 - Plant growth


Plant growth : 
  • Growth is one of the characteristic features of living organisms. 
  • Growth as a phenomenon has two aspects viz - 
  1. quantitative and 
  2. qualitative. 
Quantitative 
  • aspect speaks for an increase in the length, breadth, size, volume, body mass or dry weight and number of cells. 
  • Growth as a quantitative change is a final end product of successive metabolism. 
Qualitative 
  • aspect talks about the change in the nature of growth where development is an ordered change or progress while differentiation leads to higher and more complex state. 
Growth :
  • Permanent, irreversible increase in the bulk of an organism, accompanied by the change of form. 
  • In multicellular (vascular) plants, growth is indeterminate and occurs throughout the life indefinitely. 
  • It is restricted to some specific region called meristems which are the regions where new cells are constantly and continuously produced. 
  • Meristems are of three types based on location viz - 
  1. Apical
  2. Intercalary and 
  3. Lateral.
Do you know ? 
  • Root and stem show indefinite or indeterminate growth. However, in organs like leaves, flowers and fruits, growth is determinate. i.e. they grow up to certain genetically destined size. 
  • In unicellular plants, growth is uniform and determinate.
Do you know ? 
1. Apical meristem : 
  • In vascular plants, growth is restricted to the apices of root and shoot. 
  • Responsible for growth in length/ height and the differentiation or cell types. 
  • Contributes to the primary growth. 
2. Intercalary meristem : 
  • Located at the node or at the base of internode of stem. 
  • Primarily responsible for increasing length of internodes and also for formation of leaf primordia and lateral buds. 
3. Lateral meristem : 
  • Located laterally along the axis of dicotyledons and gymnosperms. 
  • Located as strip in the vascular bundles of stem of dicots. It is called vascular cambium.
  • Responsible for increase in the girth of the stem due to addition of secondary vascular tissues.

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