Pollen grains can be preserved at high temperature due to:
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → Sporopollenin
A pollen grain has a two-layered wall. The hard outer layer is the exine. It is made of sporopollenin, one of the most resistant organic materials known. It can withstand high temperatures and strong acids and alkali, and no enzyme is known that breaks it down. This is also why pollen grains are well preserved as fossils.
(1) Cellulose — Incorrect. Cellulose is a part of the soft inner wall, the intine. It does not protect the grain from heat.
(2) Sporopollenin — Correct. This tough exine material is what keeps the pollen grain safe at high temperature.
(3) Pectin — Incorrect. Pectin is the other part of the intine, along with cellulose. It is not heat resistant.
(4) Agarose — Incorrect. Agarose is a natural polymer from sea weeds. It is used as the gel in gel electrophoresis, and it is not a part of pollen.
NCERT Extract:
Stamen, Microsporangium and Pollen Grain – …
