Auxanometer is used to measure:

The growth period of a plant is generally divided into how many phases?

The plants,which are able to send their roots up to the fringe of water table are called

In the figure of the sigmoid growth curve given below,label segments $1$,$2$,and $3$.

Given below are two statements about plant growth.
Statement $I$: Curve for arithmetic growth is linear.
Statement $II$: Curve for geometric growth is exponential.
In the light of the above two statements,choose the most appropriate answer from the options given below.

Define and explain the following terms related to plant growth:
$(1)$ Absolute growth
$(2)$ Relative growth