Question: 2-theoretical genetic strains of a virus (a- b- c- and a+ b+ c+) are used to simultaneously infect a culture of host bacteria. Of 10,000 plaques scored, the genotypes in the following table were observed. Determine the genetic map of these three genes on the viral chromosome.

a+ b+ c+ 4100

a- b- c- 3990

a+ b- c- 740

a- b+ c+ 670

a- b+ c- 160

a+ b- c+ 140

a- b- c+ 90

a+ b+ c- 110

(hint: look at the number of plaques where a and b are the same but c is different; where a and c are the same but b is different and where b and c are the same but a is different. What does this tell you?)