Scanning electron micrograph of pollen grains from a venus flytrap (Dionaea muscipula). This carnivorous plant eats insects and other small bugs. Pollen grains contain the male gamete and are produced in the anther. They are transferred from one flower to another (pollination) so that fertilization of the female gametes can occur (sexual plant reproduction). Pollen is a common trigger of hay fever or seasonal allergies. The pollen grains are 100 microns in size across. Supplied by Kevin Mackenzie, courtesy of Wellcome Images.