Question

Starch grains in rice are:
A. Simple and concentric
B. Simple and eccentric
C. Dumbbell shaped
D. Compound

Answer 1

Hint: Rice starch is derived from Oryza sativa(botanical name of species). it is a very common form of starch available but much less common than the corn starch.Starch grains are used basically to store food in the form of polysaccharide.

Complete answer:
Starch grains are primarily a means for plants to store their energy. They are produced by a wide variety of the rice plants and are a mixture of alpha-amylose and amylopectin. They are linked by glycosidic linkage. Starch grain differ in various aspects like their size, their shape, and the structure of their center vacuole. Many of these differences are very useful for the identification of the plant and origin for the starch grain. The granules of rice starch are very small (2–4 micrometers), and are polygonal, and compound, which means, many small granules are compacted together. One of the important morphological starch grain forms found in members of the Poaceae family, called a compound starch grain, is formed by aggregation of small starch granules in an amyloplast.
Dumbbell shape is related to stomata not to the starch grains. And the concentric and eccentric are the linings present in them indication of the way the food is stored in them. These arrangements are found in simple as well as compound starch grains.

Hence, the correct option is option D i.e. compound.

Note:
When starch grains are present as individuals or single then they are known as simple. Example of this simple type is potatoes. Whereas when the starch grains are present in groups, they are called compounds. Example of compound type is rice.