Plant growth is unique in being

Movements of leaves of sensitive plant, $Mimosa \text{ } pudica$, are due to

The graph of organ size/weight versus time for the given growth shows a sigmoid curve.

Low $C/N$ ratio favours

Growth is measured by a variety of parameters,some of which are an increase in:
$a.$ Dry weight
$b.$ Fresh weight
$c.$ Volume
$d.$ Cell number

The exponential growth can be expressed as $w_1 = w_0 \cdot e^{rt}$. Identify $r$ in the given equation :