Question

Starch and cellulose are
(a) Branched polysaccharides
(b) Storage products
(c) Components of plant cell wall
(d) Composed of glucose

Answer 1

Hint: Cellulose is the main component which is present in the cell wall of plants. It makes the cell wall rigid whereas starch is used as a food reserve in the plant. Starch is the bond of many glucose molecules joined together.

Complete step by step answer:
Starch and cellulose are composed of glucose. Starch and cellulose are the polymers having the same monomers i.e. glucose. They contain the same glucose-based repeat unit but have different functions. Starch is a form of carbohydrate and the main source of energy for cells.
So, the correct answer is 'Composed of glucose'.

Additional information:
Branched polysaccharide: Polysaccharides are a long chain of monosaccharides linked by a glycosidic bond which gives support, storage and cellular communication. Branched polysaccharides are the polymers having long chains which are soluble in water, have the lowest viscosity and can precipitate. They can form a sticky paste by side-chain- side-chain interaction which is used for making adhesives or binder.
Storage products: Plants store glucose in the form of starch which is the food for plants. They store it in their leaves, stems, roots, flowers, fruits or seeds. Plants store proteins in the storage vacuoles and store carbohydrates in the long polysaccharide chains.
Component of plant cell walls: The most characteristic component of the plant cell wall is cellulose. The plant cell wall also contains several proteins, glycoproteins which include various enzymes and structural proteins. A plant cell wall is arranged in layers which contain microfibrils, hemicellulose, pectin, lignin and soluble protein.

Note: Cellulose is the most abundant macromolecule formed on earth which makes up most of the cell wall of plant cells. Cellulose is of great economic importance which is processed to produce papers and fibres. Starch can be tested by using iodine. It turns the solution blue-black in colour to show it's presence. Chinese documents were coated with starch to avoid penetration of ink. Egyptians used starch paste for the making of strips of papyrus stems.