Pollentube (IMAGE) University of Copenhagen Caption Microscopic photo of a normal pollentube and a pollentube with essential growth-genes turned off. The black line is a scale for 0.1 mm. Credit University of Copenhagen Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.