You have generated an E. coli that contains two copies of the Lac operon. One copy is I-P+O+Z-Y+A+ . The other copy is I+P+O-Z+Y+A+. ( + indicates a wild type copy and - indicates a null-mutant, non-functional copy.) You grow these bacteria on petri plates containing only lactose as a carbon source and on petri plates containing both glucose and lactose as carbon sources. Both plates contain X-gal, which turns blue in the presence of active ß- galactosidase. Which of the following describes the growth of the bacteria on the two plates?