Dividing pollen cells. Coloured scanning electron micrograph of a section through an anther from a spiderwort (Tradescantia reflexa) flower, showing pollen mother cells during various stages of meiosis I (gamete formation) - showing: chromosomes (yellow), cytoplasm (violet) and the cell wall (blue). During meiosis four daughter nuclei are formed from one parent nucleus after two stages of nuclear division. Meiosis occurs only in the sex cells (gametes).