An hfr strain of genotype: arg- lac- leu+ strs is mated with a recipient strain of genotype: arg+ lac+ leu- strr. the strs marker is known to be transferred very late. among the other three markers, leu+ is the last one to enter the f- cell. (note: all bacteria have the ability to utilize glucose as a sugar source. the alleles arg+and leu+ are necessary for synthesis of arginine and leucine respectively. the lac+ is necessary for utilization of lactose.)exconjugants are plated on a medium containing glucose, streptomycin, and arginine. the following results are obtained for 500 colonies isolated from these plates and tested for growth on various media: minimal medium (with glucose): 135 coloniesminimal medium (without glucose) + lactose: 85 coloniesminimal medium (without glucose) + lactose + arginine: 90 coloniesa) write a list of possible genotypes from those 500 colonies, and indicate the number in each genotype. show your work and circle your answer. provide a detailed explanation for each answer. b) calculate the recombination frequencies. show your work and circle your answer. provide a detailed explanation as to why those certain genotypes and numbers are used to calculate the recombination frequencies. i do not understand how the rf are calculated. c. ) what is the gene order? include the position of the origin of transfer.