Identify the types of growth shown in the figure below.

The leaves of $Mimosa$ $pudica$ (Sensitive Plant) droop down on touch because

$A$ rubber band stretches and reverts back to its original position. Bubble gum stretches,but it would not return to its original position. Is there any difference between the two processes? Discuss it with respect to plant growth. [Hint: Elasticity (reversible),Plasticity (irreversible)]

Example of positive geotropism is

Thigmotropism is best seen in

When certain tomato plants are kept in a dark room for a few days,they develop an albinism-like color. What is this phenomenon called?