6) You isolate a lambda phage that overproduces uncleavable cI. Is this mutation likely to be dominant or recessive? a.Recessive b.Dominant 7) You mutagenize cells with an agent that causes transiti

6) You isolate a lambda phage that overproduces uncleavable cI. Is this mutation likely to be dominant or recessive?

a.Recessive

b.Dominant

10) An Hfr strain lacZ- lacY+ pro+ Strs is crossed against an F- lacZ+ lacY- pro- StrR strain. After about two hours, the mixture was plated onto media containing streptomycin but no proline. Afterwards, the pro+ StrR recombinants were tested for their ability to grow on lactose as the sole carbon source. pro+ lac+ colonies were extremely rare and the majority of the colonies were pro+ lac-. What is the most likely order of lacZ and lacY relative to pro? (hint: a second cross Hfr+ lacZ+ lacY- pro+ StrS X F- lacZ- lacY+ pro- StrR has many lac+ pro+ colonies).

a.lacY pro lacZ

b.pro lacY lacZ

c.lacY lacZ pro

d.lacZ lacY pro