TLS Online TPP Program

#Question id: 15845


You have isolated two temperature-sensitive mutations in phage l that you suspect may be in the same gene. These phage mutants are called ts-1 and ts-2. Each mutant will form plaques at 35˚C but not at 42˚C. You cross ts-1 to ts-2 phage by coinfecting E. coli at the permissive temperature of 35˚C. When the resulting phage lysate is plated at 35˚C you count 10,000 plaques per ml of phage lysate, but when the same phage lysate is plated at 42˚C, there are only 80 plaques per ml. Find out the relative order of sm, ts-1 and ts-2?

#Unit 8. Inheritance Biology
  1. ts-2→ts-1→sm
  2. ts-1→sm→ts-2
  3. sm→ts-1→ts-2
  4. sm→ts-2→ts-1