Elongation of roots:
$a.$ Occurs at a constant rate
$b.$ Can be expressed by equation $W_t = W_0 e^{rt}$
$c.$ Shows arithmetic growth pattern

Assertion $(S)$: Growth occurs when anabolic processes exceed catabolic processes.
Reason $(R)$: Growth is the result of metabolism.
$(A)$ Both $S$ and $R$ are true,and $R$ is the correct explanation of $S$.
$(B)$ Both $S$ and $R$ are true,but $R$ is not the correct explanation of $S$.
$(C)$ $S$ is true and $R$ is false.
$(D)$ $S$ is false and $R$ is true.

Which of the following is the result of metabolism?

Select the correct option for the absolute growth and relative growth of the leaf shown below.

$A$ leaf of $20 \; cm^{2}$ grows $5 \; cm^{2}$ per hour and a leaf of $25 \; cm^{2}$ grows $5 \; cm^{2}$ per hour. The relative growth rate of leaf $A$ and $B$ respectively is:

The coiling of garden pea tendrils around a support is an example of which phenomenon?