Question

The given figure shows growth of two leaves over the period of one day. If, AG = absolute growth and RGR = relative growth rate, then select the correct option.


$\begin{array}{ccccc}& \text{A-Leaf}& & \text{B-Leaf}& \\ & \text{AG}& \text{RGR}& \text{AG}& \text{RGR}\\ \text{(a)}& \text{1 \%}& \text{1}& \text{2 \%}& \text{2}\\ \text{(b)}& \text{100 \%}& \text{5}& \text{10 \%}& \text{5}\\ \text{(c)}& 5c{m}^2& \text{100 \%}& 5c{m}^2& \text{10 \%}\\ \text{(d)}& 5c{m}^2& \text{100 \%}& 5c{m}^2& \text{100 \%}\end{array}$

• A. a
• B. b
• C. c
• D. d

Answer 1

The correct option is C c

Absolute growth rate (AGR) is the increase in total growth of two organs or organisms is measured and comparison of total growth per unit time.
Relative growth rate (RGR) is growth per unit time per unit initial growth.

$RGR=\frac{\text{Growth in given time period}}{\text{Measurement at start of time period}}$

Therefore,

Absolute growth of leaf $A=10c{m}^2-5c{m}^2=5c{m}^2$

Relative growth rate for leaf $A=5/5\times 100=100\%$

Absolute growth for leaf $B=55c{m}^2-50c{m}^2=5c{m}^2$

Relative growth rate for leaf $B=5/50\times 100=10\%$

Though the absolute growth is same for both the leaves (A and B) but the relative rate of growth is more in leaf A because of its initial small size.

Hence, option c is the correct answer.