Chemotropism is the movement of a part of the plant in response to a chemical stimulus. It can be positive chemotropism or negative chemotropism. Example: The growth of pollen tube towards a chemical which is produced by an ovule during the process of fertilisation in a flower. Two plant hormones with their functions are as follows: Auxins promote cell elongation, root formation, cell division, respiration and other physiological processes like protein synthesis, etc.
Gibberellins stimulate stem elongation, seed germination and flowering.