Starch is a homopolysaccharide. It is a polymer of glucose.

It has 2 components -

1. Unbranched component (Amylose) -
It consists of 200 - 1,000 glucose molecules (alpha-D-glucose molecules bonded with alpha 1-4 glycosidic linkage). It is helical (each turn consists of 6 glucose units).

2. Branched  component (Amylopectin) -
It consists of alpha-D-glucose molecules bonded with alpha 1-4 glycosidic linkage in straight chain and alpha 1-6 glycosidic linkage at branching points. It consists of 2,000 to 200,000 glucose molecules in straight chain and branches after every 25 glucose units.

Hello Ram Mohan,

Starch is a homopolymers by units of glucose and the storage form of carbohydrates plants.
It is synthesized by the most part of vegetable cells and stored especially in seeds (e.g. cereals and legumes), tubers (e.g. potatoes), roots (e.g. those of carrots) and some fruits (e.g. green banana).

Amylopectin represents about 80% of polysaccharide taken up with diet.
It is a branched molecule formed by thousands of glucose units, up to 50000, that, in main chain, are joined by α-(1→4) glycosidic bonds.

Hope it helped you

Thank you