Eight mutant bacteriophage strains cannot lyse a certain type of bacteria that can be lysed by wild-type bacteriophages. The mutant strains were allowed to infect the bacteria in a complementation test. A "+" indicates that lysis occurred with coinfection. A "-" indicates that lysis did not occur.1. A cistron is defined by no complementation in the (cis/trans) configuration.2. How many genes are mutated in this experiment?3. Which of the following strains below are defective in the same gene as strain 7? Answer yes if the strain is defective or no if it is not. 1 2 3 4 5 6 7 81 - + + - + + + -2 - + + + - + +3 - + + + + +4 - + + + -5 - + - +6 - + +7 - +8 -Strain Defective1 yes/no2 yes/no3 yes/no4 yes/no5 yes/no6 yes/no7 N/A8 yes/no