Solution

Growth of a cell, organ, plant or population follows a sigmoid (S-shaped) curve with three main phases.
Lag phase: growth is slow at first, as cells prepare to divide.
Exponential (log) phase: growth is very rapid; the number of cells or the size increases geometrically. The growth rate is maximum in this phase.
Stationary (steady) phase: growth slows down and stops because nutrients become limiting; this may be followed by senescence (decline).
So the maximum growth rate occurs in the exponential phase.

Concept Sigmoid growth curve

Plant Growth and Development in past papers

85 questions from this chapter have appeared across 24 exam years.