(a) It is the graphic representation of the total growth against time.
(b) The period of time in which growth takes place has been called grand period of growth by Sachs.
© The rate of growth is not uniform during grand period of growth.
(d) If total growth is plotted against time; a S-shaped oir sigmoid curve is obtained. It consists of four parts- lag phase, exponential phase (log phase), phase of diminishing growth and stationary phase.