Question

Sporopollenin, an organic material, is present in:

• A. Stigma
• B. Intine
• C. Exine
• D. Style

Answer 1

The correct option is C Exine

Wall of pollen grains is made up of two layers -

• An outer thick and protective exine made up of sporopollenin
• An inner thin and uniform intine made up of cellulose and pectin

Sporopollenin

• The exine is composed of sporopollenin which is considered to be the most resistant organic material known. Thus it provides protection to the pollen grains.
• Sporopollenin is capable of withstanding high temperature, strong acids and alkali and cannot be degraded by any known enzymes.
• The exine is not a continuous layer and has apertures known as germ pores where the sporopollenin is absent. During pollen germination, the intine comes out of the germ pore as a pollen tube.