Double fertilization are contained within pollen grains. They develop within the microsporangia, or pollen sacs, of the anthers on the stamens. Each microsporangium contains diploid microspore mother cells, or microsporocytes. Each microsporocyte undergoes meiosis, forming four haploid microspores, each of which can eventually develop into a pollen grain. A microspore undergoes mitosis and cytokinesis in order to produce two separate cells, the generative cell and the tube cell. These two cells in addition to the spore wall make up an immature pollen grain. As the male gametophyte matures, the generative cell passes into the tube cell, and the generative cell undergoes mitosis,
Gum (botany) Gum (botany) Gum is a sap or other resinous material associated with certain species of the plant kingdom. This material is often polysaccharide-based and is most frequently associated with woody plants, particularly under the bark or as a seed coating. The polysaccharide material is typically of high molecular weight and most often highly hydrophilic or hydrocolloidal. Many gums occur as seed coatings for plant species; the adaptive purpose of some of these gummy coatings is to delay germination of certain flora seeds. An example of such a gummy coating occurs in the case of Western poison oak, a widespread shrub