Chemical nature of sporopollenin is:

The correct answer is Option (2) → Organic

The pollen grain has a two-layered wall. Its hard outer layer, the exine, is made of sporopollenin. Sporopollenin is one of the most resistant organic materials known. It can stand high temperatures, strong acids and alkalis, and no enzyme is known that breaks it down. This is why pollen grains are well preserved as fossils.

(1) Inorganic — Incorrect. Sporopollenin is a carbon-based compound made by the living cell, so it is organic, not inorganic.

(2) Organic — Correct. Sporopollenin is a very resistant organic material.

(3) Metallic — Incorrect. “Metallic” describes metals. It does not describe sporopollenin.

(4) Non-metallic — Incorrect. “Non-metallic” is used for chemical elements. It is not the term used for the chemical nature of sporopollenin.

NCERT Extract:
Stamen, Microsporangium and Pollen Grain – …