Explanation

In the given graphs, only ‘A’ shows the linear growth curve. Arithmetic Growth Rate The expression of arithmetic growth is exemplified by roots (or organ) elongating at constant rate. On plotting the length of an organ against time, a linear curve is obtained. Mathematically it is expressed as [image:15_image13.emf] Constant linear growth, a plot of length L against time $L_{t} = L_{0} + rt$ $L_{t}$ = Length of time ‘$t$’ $L_{0}$ = Length of time to $r$ = Growth rate or elongation per unit time