You have isolated two different mutations in the mi gene of the phage lambda that makes tiny plaques. These mutations are called mi-1- and mi-2-. From DNA sequencing, you know that the mi-1- mutation is a 1 frameshift, but you do not know the nature of the mi-2- mutation. You cross an mi-1- phage with a mi-2- phage by coinfecting E. coli with phage of both types so that each cell receives at least one phage of each type. Of the 1000 plaques that result from the cross, only 8 form large plaques while the rest are tiny.


Required:

a. What is the distance between the mi-1^- and mi-2^- mutations in map units?

b. The genome of phage λ is 5x10^5 bp in physical length and 200 map units in genetic length. What is the distance between mi-1^- and mi-2^- mutations in base pairs?