07 Plant Growth and Mineral Nutrition - part 02 - Phases of growth

07 Plant Growth and Mineral Nutrition - part 02 - Phases of growth


Phases of growth : 
  • The cells in the meristem divide, enlarge and get differentiated. 
  • Corresponding to these three stages, there are three phases of growth - 
  1. Phase of cell division/ formation
  2. Phase of cell enlargement/ elongation
  3. Phase of Cell maturation/ differentiation
 1. Phase of cell division/ formation : 
  • Cells of meristem are thin walled, non-vacuolated having prominent nucleus and granular cytoplasm. 
  • Meristematic cell undergoes mitotic division to form two new cells. 
  • One cell remains meristematic and the other cell undergoes enlargement and differentiation. 
  • In this phase, rate of growth occurs at a slower pace (Lag phase). 
2. Phase of cell enlargement/ elongation : 

  • The newly formed cell becomes vacuolated, osmotically active and turgid due to absorption of water. 
  • The turgidity results in the enlargement of cell - both lengthwise and breadthwise. 
  • In this phase new wall materials and other materials are synthesized to cope up with the enlargement. 
  • The growth rate in this phase occurs at an accelerated pace (exponential or Log phase).
C. Phase of Cell maturation/ differentiation : 
  • The enlarged cell now becomes specialized to perform specific fuction and attains maturity- both morphological and physiological. 
  • In this phase, rate of growth slows down and comes to a steady state (stationary phase).

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