Question

(i)Starch is a polymer of (ii) basic unit of:
A. Fructose
B. Glucose
C. Sucrose
D. Maltose

Answer 1

Hint: We all know that the end-product of photosynthesis is starch. It is stored inside the plant in various forms. Starch is a polymer. It provides energy to the plant for carrying out its various life processes most importantly, metabolism, which may be defined as the sum total of the numerous and various chemical reactions that take place inside the body of plants.

Complete step-by-step answer:
To solve the given question, we must be well aware of starch.
The monomer of starch is α-D glucose. The sugar that is produced after photosynthesis is converted into starch. Starch is made up of amylopectin and amylose. Amylopectin makes up 80-85% of the starch. It has a branched structure and consists of glucose monomers linked with the help of α-1, 4 links and α-1, 6 links. Amylose constitutes only 15-20 percent of the starch. It has a straight chain structure in which the glucose monomers are linked by α-1, 4 links.
Amylose is more soluble in water because of the presence of a less complex structure as compared to amylopectin.
Sucrose is the common table sugar. Maltose is a reducing sugar formed when starch is degraded. Fructose is the fruit sugar found in fruits.

Hence, the correct option is (B) glucose.

Note:
Here it must be noted that starch turns bluish- black in colour when iodine is added to it. This is because of the presence of amylose in its structure. Amylopectin gives a reddish-purple colour when iodine is added to it. Rice, potato, banana, and cereals are rich in starch.