In a tiny worm, a close-up view of where genes are working
(PHYSorg.com Biology)

Scientists have long prized the roundworm Caenorhabditis elegans as a model for studying the biology of multicellular organisms. The millimeter-long worms are easy to grow in the lab and manipulate genetically, and have only around 1,000 cells, making them a powerful system for probing intricacies of development, behavior and metabolism.