In E coli four Hfr strains donate the following markers Each

In E. coli, four Hfr strains donate the following markers. (Each alphabetic letter represents 1 marker; thus, each strain donates 5 markers.)

Following are the markers, in the order donated:

Strain 1: A Z L U B

Strain 2: X T C B U

Strain 3: T X D K E

Strain 4: Z A E K D

All of these strains are derived from the same F- strain. If markers A and Z are the first two markers, what is the order of these markers on the circular chromosome of the original F+?

Solution

Answer:

The order of the markers are as under:

1. A-Z-L-U-B (Forward)

2. X-T-C-B-U (Reverse)

3. T-X-D-K-E (Forward)

4. Z-A-E-K-D (Reverse)

So, the order of the markers are:

A-Z-L-U-B-C-T-X-D-K-E