What is the general name of chemical substances which bring about control and coordination in plants?

Name the following: The special cells which bring about control and co-ordination.

What is the name of the chemical substance which constitutes the genes ?

Name two tissues which provide control and coordination in animals.

Chemical messengers which control and coordination in plants and animals are called .......

The chemical substance P is made and secreted by the meristematic tissue at the tip of stem (or shoot) of a plant. The chemical substance P is responsible for a phenomenon Q in plants in which the stem bends towards the source of light. The same chemical substance P has an opposite effect on the root of a plant. It causes the root of a plant to bend away from the source of light in a process called R. What is the general name of the chemical substance like P ? Name another substance which belongs to this class of chemical substances.

Name the hormone which brings about inter nodal elongation ?