Question

Pollen grains are well preserved as fossils because of the presence of ________.

• A. Cellulose
• B. Sporopollenin
• C. Lignocellulose
• D. Pectocellulose

Hint:

Sporopollenin is specifically associated with the EXINE (outer layer) of the pollen. The inner layer (intine) is made of relatively fragile pectocellulose.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept: Pollen grains possess a highly specialized two-layered wall, with the outer layer uniquely adapted for extreme environmental durability.
Step 2: Key Formula or Approach: Identify the specific organic chemical compound that confers extreme resistance to degradation in the outer pollen wall.
Step 3: Detailed Explanation: The outer prominent layer of the pollen grain is called the exine.
The exine is made up of a highly complex organic polymer called sporopollenin.
Sporopollenin is widely renowned as one of the most resistant organic materials known in the biological world.
It can effortlessly withstand extremely high temperatures, strong acids, and strong alkalis.
Furthermore, no known biological enzyme has been discovered that can successfully degrade sporopollenin.
Because of this unparalleled chemical resistance, pollen grains remain intact over millions of years and are exceptionally well preserved as microfossils in geological strata.
Step 4: Final Answer: The presence of sporopollenin is directly responsible for this preservation.