The movement in the "Touch-me-not" plant $(Mimosa pudica)$ in response to touch is known as:

What is a $Cactushouse$?

Describe the following plant growth regulators:
$(1)$ Gibberellins
$(2)$ Cytokinins

Match the following:
Column-$A$ | Column-$B$
$(1)$ Auxin | $(I)$ Ripening and maturity of fruits
$(2)$ Gibberellin | $(II)$ Differentiation of xylem elements
$(3)$ Cytokinin | $(III)$ Prevention of genetic and physiological dwarfism
$(4)$ Ethylene | $(IV)$ Found from tumour tissue of tobacco

Which of the following sets is not a natural plant growth regulator?

List five main groups of natural plant growth regulators. Write a note on discovery,physiological functions and agricultural/horticultural applications of any one of them.