Question

Typical growth curve in plants is

(a) stair­-steps shaped

(b) parabolic

(c) sigmoid

(d) linear.

Answer 1

Ans : (c) sigmoid

Explanation :

Geometric growth cannot be sustained for long in natural condition. Limited nutrient availability slows down the growth. It leads to a stationary phase or even a decline. Plotting the growth against time, gives a typical sigmoid or S-curve. Sigmoid curve of growth is typical of most organisms in their natural environment including plants. The exponential growth can be expressed as: W₁ = W₀e^rt;

where

W₀ = initial size at the beginning of the period

W₀ = initial size at the beginning of the period

r = growth rate

t = time of growth

e = base of natural logarithms

As idealised sigmoid growth curve is drawn below: