Understanding Pollen

Pollen is essentially a fine or coarse powder containing microgametophytes that produce male gametes or sperm cells. The study of pollen and its characteristics falls under the purview of Palynology, a specialized branch of Biology.

Defining Pollen Grains

Pollen grains are minuscule structures that carry the androecium, the male reproductive part of a flower. Inside a pollen grain, you will find cytoplasm as well as a tube cell that transforms into a pollen tube. The generative cell releases the sperm nuclei.

Further Reading: Pollination

Understanding the Structure of Pollen Grains

Pollen grains, though microscopic, can vary in size and structure. The size of the grains is usually species-specific, but generally, they range between three to two hundred micrometres or microns. Pollen grains can be round, ovule, triangular, disc or bean-shaped, with a smooth or spiky surface. While the natural color of pollen grains is white, it can change based on the plant species, with some appearing yellow, orange, cream, etc.

A pollen grain is composed of three parts:

1. The cell interior, filled with living cytoplasm, deteriorates quickly during fossilisation.
2. The intine, or the inner layer of the cell wall, contains cellulose and pectin. Like cytoplasm, the intine also degrades rapidly during fossilisation.
3. The exine, or the outer layer of the cell wall, is primarily composed of sporopollenin. This N-free polymeric substance is one of the most resistant substances and belongs to the diverse class of organic compounds known as terpenes.

Recommended Reading: Fertilization in Plants

This article provides a basic understanding of pollen, pollen grains, and their physical characteristics. For more information on pollen grains, their types, functions, and other related topics, keep visiting our website.