Question

The strains below show the results of interrupted mating experiments with 3 different Hfr strains. HFR Strain 1 order of transfer: A, B, E, D, F HFR Strain 2 order of transfer: D, F, C, G, A HFR Strain 3 order of transfer: D, E, B, A, G What is the order of the genes, starting with C?

1) C, G, A, D, F, B, E
2) C, F, D, B, A, E, G
3) C, B, E, D, F, G, A
4) C, G, A, B, E, D, F
5) C, D, F, G, A, B, E

Answer 1

The order of genes on a bacterial chromosome determined from interrupted mating experiments is option 1: C, G, A, D, F, B, E, derived from overlapping sequences of three different Hfr strains.

Step-by-step explanation:

Based on the results of interrupted mating experiments with three different Hfr strains, we can determine the order of the genes on a bacterial chromosome. Since each Hfr strain transfers genes in a specific sequence, we can overlap their sequences to find a consistent order. For example, Strain 1 transfers A before B and E before D, while Strain 2 transfers D before F, and Strain 3 transfers D before E and B. By analyzing these sequences, we can deduce the overall order of these genes.

Taking the starting point with C as requested, we can use the order provided by Strain 2, which includes C. The sequence begins with C, followed by G, A, D, and F, as given by Strain 2. We then can incorporate the order provided by Strain 1 and 3 to find that B and E follow F in the sequence. Putting this all together, we get the complete ordered sequence: C, G, A, D, F, B, E.

Therefore, the correct order of the genes, starting with C, is option 1: C, G, A, D, F, B, E.