Microsporocyte or microspore mother cells are polygonal and closely packed initially. Pollen grains develop from them in pollen sacs of anthers. As anther enlarges, pollen sac becomes loosely arranged. A few microsporocytes becomes non-functional and are absorbed by developing microspores. Each microsporocyte undergoes meiosis and from four haploid nuclei (microspores or pollen gains). They arrange in a tetrahedral manner. later on each microspore separates and develops into a mature pollen grain.
