Growth in length of a plant can be measured by

The growth period of a plant is generally divided into:

Which parameter is used to measure the growth in flat organs like leaves?

Tropic movement is due to

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

The rate of growth of any organism follows