In the cross Hfr aro + arg + ery r str s x F - aro - arg - ery s str r the marke
ID: 49083 • Letter: I
Question
In the cross
Hfr aro+ arg+ eryr strs x F-aro- arg- erys strr
the markers are transferred in the order given (with aro+ entering first), but the first three genes are very close together. Exconjugants are plated on a medium containing strepotomycin, erythromycin, arginine and aromatic amino acids. The following results are obtained for 300 colonies isolated from these plates and tested for growth on various media: on Ery only plates, 263 strains grow; on Ery + Arg plates, 264 strains grow; on Ery + Aro plates, 290 strains grow; on Ery + Arg + Aro plates, 300 strains grow.
How many map units are between the aro and ery genes?
3.3
6.6
11
12.7
13.2
14.7
15.9
3.3
6.6
11
12.7
13.2
14.7
15.9
Explanation / Answer
11 map units