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.

	$AG$ for leaf $A$	$RGR$ for leaf $A$	$AG$ for leaf $B$	$RGR$ for leaf $B$
(a)$\,\,$	$1\%\,\,$	$1\,\,$	$2\%\,\,$	$2$
(b)$\,\,$	$100\%\,\,$	$5\,\,$	$10\%\,\,$	$5$
(c)$\,\,$	$5\,\,$	$100\%\,\,$	$5\,\,$	$10\%$
(d)$\,\,$	$5\,\,$	$100\%\,\,$	$5\,\,$	$100\%$

• A. a
• B. b
• C. c
• D. d

Answer 1

Answer: (C)

Absolute growth rate $(AGR)$ : Increase in total growth of two organs or organisms is measured and comparison of total growth per unit time is called absolute growth. Absolute growth rate is the total growth per unit time.
Relative growth rate $(RGR)$ : It is growth per unit time per unit initial growth.
$RGR=\frac{\text{Growth in given time period}}{\text{Measurement at start of time period}}$
$AG$ for leaf $A=10\,cm^{2}-5\,cm^{2}=5\,cm^{2}$
$RGR$ for leaf $A=\frac{5}{5}\times100=100\%$
$AG$ for leaf $B=55\,cm^{2}-50\,cm^{2}=5\,cm^{2}$
$RGR$ for leaf $B=\frac{5}{50}\times100=10\%$
Though the absolute growth is same for both the leaves ($A$ and $B$), relative rate of growth is more in leaf $A$ because of its initial small size.