Pollen tube by recognition and hydration of the pollen that allows for germination of the tube and ultimate growth. In the pollen grain, the generative cell gives rise to the sperm, whereas the vegetative cells have a tube cell that grows the pollen tube. There is competition in this step as many pollen grains may compete to reach the egg. The stigma plays a role in guiding the sperm to a receptive ovule, in the case of many ovules. Only compatible pollen grains are allowed to grow as determined by signaling with the stigma. Some plants have mechanisms in place to prevent
Xylan (coating) Xylan (coating) Xylan is a fluoropolymer-based industrial coating. Generally, it is applied in a thin film to the target material. Xylan is generally used to reduce friction, improve wear resistance, and for non-stick applications. Additionally, it can be used to protect a metal from corrosion. The most commonly known application is in non-stick cookware but Xylan coatings have also been used extensively in the automotive industry and for corrosion protection in the oil and gas industry. Xylan is the umbrella trademark for most of the Whitford Corporation fluoropolymer coatings line. Xylan is made of low friction, wear resistant composites of