Auxanometer is used to measure:

Shock movement in 'touch-me-not' plant is

Which process is essential for the growth of an organism?

$A$ dark-grown,pale,and undifferentiated seedling is called:

Assertion $(A)$: Morphogenesis and differentiation occur during the process of growth.
Reason $(R)$: The number of cells increases during growth.

In the sigmoid growth curve,the alphabets indicate the sequence of events. Choose the correct option where the alphabet specifies the event.