Why is auxin called a growth regulator?

Which one of the plant growth regulators would you use if you are asked to : Induce rooting in a twig

Which one of the plant growth regulations would be used if you are asked to induce rooting

Which one of the plant growth regulations would be used if you are asked to delay in senscence

Which one of the plant growth regulations would be used if you are asked to increase height of a dwarf plant

Which one of the plant growth regulations would be used if you are asked to induce stomatal closing in leaves

Which one of the plant growth regulations would be used if you are asked to chloroplast formation in the presence of light

Which one of the plant growth regulations would be used if you are asked to Quick ripening of fruits.

Give the scientific reasons: Chemotropism is called growth relevant movement.

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.

What are the types of growth regulators?