Pollen tube through wind, water or pollinators. The last step before fertilization is the growth of the pollen tube to transfer non-motile sperm to the protected egg. Pollen tubes are unique to plants and their structure had evolved over plant history. The pollen tube formation is complex and the mechanism is not fully understood, but is of great interest to scientists. Pollen is produced by the stamen, the male reproductive organ of the flower. Each pollen grain contains a vegetative cell, and a generative cell that divides to form two sperm cells. The pollen is delivered by the opening of anthers for
Resistant starch manufactured foods. Starches with high amylose content generally have increased resistant starch. Resistant starch (RS) is any starch or starch digestion products that are not digested and absorbed in the stomach or small intestine and pass on to the large intestine. RS has been categorized into four types: Processing may affect the natural resistant starch content of foods. In general, processes that break down structural barriers to digestion reduce resistant starch content, with greater reductions resulting from processing. Whole grain wheat may contain as high as 14% resistant starch, while milled wheat flour may contain only 2%. Resistant starch content