Prorocentrum (IMAGE) University of Oldenburg Caption Cross-section of a cell of the microalga Prorocentrum cordatum. The nucleus with the chromosomes is on the right. A single barrel-like chloroplast takes up 40 percent of the cell volume. Credit University of Oldenburg / General and Molecular Microbiology group Usage Restrictions Only use with appropriate credit and in connection with press release. 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.