Helices (image) Harvard University Caption This is an illustration of a helix (top), a hemihelix with one perversion marked by an arrow (middle), and a hemihelix with multiple perversions (bottom). The scale bar is 5 cm for each image. Credit Jiangshui Huang Usage Restrictions None 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.