In order to better understand arginine biosynthesis in bacteria, a microbial geneticist might first isolate mutant bacterial strains.
a. What characteristics must these mutant bacteria have?
b. Outline a strategy for isolating such mutants.
c. List three possible methods for mapping the genetic location of the mutations in these strains.

a. The mutant bacterial strains must have a deficiency in the ability to produce arginine, which is the end product of the arginine biosynthesis pathway. This deficiency could be due to mutations in the genes involved in the biosynthesis pathway.

b. The strategy for isolating such mutants would involve subjecting a population of bacteria to mutagenesis, either through chemical mutagens or radiation, to induce random mutations in their genomes. The bacteria would then be screened for their ability to produce arginine, and those with a deficiency in arginine production would be isolated as potential mutant strains.

c. Three possible methods for mapping the genetic location of the mutations in these strains include:
1. Whole-genome sequencing: This method involves sequencing the entire genome of the mutant bacteria to identify the specific mutations responsible for the deficiency in arginine production.
2. Genetic linkage analysis: This method involves crossing the mutant bacteria with wild-type bacteria and analyzing the segregation of the mutant phenotype in the progeny to map the location of the mutation.
3. Transposon mutagenesis: This method involves using transposons, or "jumping genes," to randomly insert into the bacterial genome and disrupt gene function. By identifying the location of the transposon insertion in the mutant bacteria, the genetic location of the mutation can be mapped.