20. Where are the following hormones synthesised in plants?

(a) IAA

(b) Gibberellins

(c) Cytokinins


(a) IAA Indole acetic acid is the chemical name of auxin. It is synthesised at the growing apices of the plant, e.g.. shoot tip, leaf primordia ancl developing seeds.

(b) Gibberellins lt plays an important role in seed germination of plants and is synthesised in the apical shoot buds, young leaves, root tins and developing seeds.
(c) Cytokinins This plays an important role in actively dividing cells and are synthesised mainly in roots, but syntheses also occurs in endosperm of seeds growing embryo and seeds etc.