In an experiment you have a U-Tube with two strains of bacteria in two arms. In one arm the bacteria are Gal+ and His-, in other the strain is Gal- and His+. If the two arms are joined by a membrane that doesn t allow bacterial cells to pass to opposite site what will you observe when you plate each arm bacterial strain on minimal media?

• A. None will grow
• B. Some colonies seen in right arm
• C. Some colonies seen in left arm
• D. Some colonies seen in both arms