Question

You perform a co-transduction experiment with pro+ gal+ arg- man- donor and pro- gal- arg+ man+ recipient. On master plate 1, you select for 1000 pro+ transductants. By screening, you find 400 colonies are gal+, 290 are arg+, and 1000 are man+. On master plate 2, you select for 1000 gal+ transductants. By screening, you find 390 colonies are pro+, 289 are arg+, and 900 are man+. Circle ALL of the following orders which may be possible given the above results. (All or nothing) a. gal---arg---man---pro b. arg---pro---gal---man c. arg--- man---pro---gal d. pro---arg---gal--- man e. pro---gal---man---arg f. pro---gal---arg---man g. None of the above'

Answer 1

Answer:

arg---pro---gal---man.

Explanation:

The co transduction frequency is directly proportional to the distance between two genes.

The recombination frequency can be calculated as follows;

A - B = (A - B / A ) x 100

Here, A and B represent the different genes.

For plate 1 :

Pro- gal = A - B = (1000 - 400/1000) x 100 = 60% . Here, A is Pro and B is gal.

Pro - Arg = A - C = (1000- 290/1000) x 100 = 71% . Here, C is Arg.

Pro - Man = A - D = (1000-1000/1000) x 100 = 0%. Here D is Man.

For Gal transductants of plate 2

Gal - Pro = A - B = (1000 - 390/1000) x 100 = 61% . Here A is Gal and B is Pro.

Gal - Arg = A - C = (1000- 289/1000) x 100 = 71% .  Here, C is Arg.

Gal - Man = A - D = (1000-900/1000) x 100 = 10%. Here D is Man.

From the recombination frequencies it is clear that the location of genes are in the order of

Thus, the correct answer is option (B).