Pollen tube Pollen tube A pollen tube is a tubular structure produced by the male gametophyte of seed plants when it germinates. It acts as a conduit to transport the male gamete cells from the pollen grain—either from the stigma (in flowering plants) to the ovules at the base of the pistil or directly through ovule tissue in some gymnosperms. In maize, this single cell can grow longer than to traverse the length of the pistil. Pollen tubes were first discovered by Giovanni Battista Amici. They are used as a model for understanding plant cell behavior. Research is ongoing to comprehend how
Development of Spore survive in a strange world, with elements of "Nintendogs". The mobile phone version of "Spore", called "Spore Origins", was based on the tide pool phase, in which players try to survive as a multicellular organism, with gameplay similar to "flOw". On March 6, 2008, an iPhone version was demonstrated at Apple's iPhone SDK press event, though there was no commitment to ship such a product given at that event. The iPhone-Spore demo made use of the device's touch capabilities and 3-axis accelerometer. Electronic Arts confirmed on March 31, 2008 that "Spore" would be receiving post-release expansion packs. Only one expansion