lac operon alleles

[toughbioz]

hey all! this is my first time on a science forum... mainly because i just cant get this problem!

 

Hopefully someone here can help me out...

 

 

Jacob and Monod used the F’ plasmid in their experiments with the lac operon and constructed merodiploids (partial diploids in which there are two copies of some genes (See figure 17.10)

 

For each of the merodiploid strains containing the lac Operon alleles listed, indicate whether the strain is inducible, constitutive, or unable to express

 

β-galactosidase and permease.

 

 

 

Strain β-galactosidase Permease

 

 

 

a. I⁺ O⁺ Z^-Y⁺ / I⁺ O^c Z⁺ Y⁺

 

 

 

b. I⁺ O⁺ Z⁺ Y⁺ / I^- O^c Z⁺ Y ^–

 

 

 

c. I⁺ O⁺ Z^- Y⁺/ I^- O⁺ Z⁺ Y^-

 

 

 

d. I^- P^-O⁺ Z⁺Y^- / I⁺ P⁺ O^c Z^- Y⁺

 

 

 

e. I^s O⁺ Z⁺ Y⁺/ I^- O⁺ Z⁺ Y^-

 

 

 

 

 

 

 

 

I dont even know where to start... how does one determine if the strain is inducible?!

 

Thanks in advance!

 

 

 

[Genecks]

This is basic stuff. Show us some effort.

It's not that hard if you think about it.

Visualize the things.

[CharonY]

I am not sure whether visualization would help, however, start by describing what each of the letters means. What phenotype would follow each of the alleles individually and how would the combination look like? It is really just a matter of assigning letters to functions.