Question

Which of the following has proved helpful in preserving pollen as fossils ?

• A. Pollenkitt
• B. Oil content
• C. Cellulosic intine
• D. Sporopollenin

Answer 1

The Correct Option is D

To determine which component is helpful in preserving pollen as fossils, we need to understand the structural components of pollen grains and their resistance to decay.

Pollen grains have a tough outer wall and a softer inner wall, structured as follows:

• Pollenkitt: This is a sticky coating found on the surface of pollen grains, primarily aiding in pollination by helping pollen stick to pollinators. It does not play a significant role in preservation.
• Oil content: Pollen contains oils, but these help in pollen's nutrition and dispersal rather than preservation.
• Cellulosic intine: The intine is the inner layer of the pollen wall, composed mainly of cellulose and pectin. It is not as resistant to decay and, therefore, not significantly involved in the fossilization of pollen.
• Sporopollenin: This is the primary component of the exine, the tough outer layer of the pollen wall. Sporopollenin is known for its exceptional resistance to decomposition by enzymes, chemicals, and microbial action. As a result, sporopollenin preserves the pollen wall structure for long periods, making pollen grains one of the most durable plant materials.

Thus, the correct answer is Sporopollenin, as it is the component that makes the exine layer of pollen resistant to decay, thereby aiding in preservation as fossils over geological timescales.

Conclusion: Sporopollenin is the key to pollen preservation in the fossil record due to its chemical stability and resistance to degradation.