<i>Arabidopsis</i> Root (IMAGE) Norwich BioScience Institutes Caption This is an Arabidopsis root tip after cold treatment showing the expression of two fluorescent copies of FLC (red and yellow). Every cell contains genes for red-FLC and yellow-FLC, but cells on the left (yellow) have turned red-FLC off while cells on the right (red) have turned yellow-FLC off. A few cells in the middle (orange) have both copies on. Patches of cells of the same colour descended from a common ancestor cell, showing that the on/off pattern is passed on through cell division. Credit Scott Berry, the John Innes Centre Usage Restrictions Copyright Berry et al. This article is distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use and redistribution provided that the original author and source are credited. 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.