D Question 10 1 pts The following shows the genotype of a partial diploid bacter
ID: 210065 • Letter: D
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D Question 10 1 pts The following shows the genotype of a partial diploid bacterial cell - where one chromosomal region containing the lac operon in E,coli is given, and the other fragment is from a plasmid carrying another lac operon from another source. The two are separated by a slash (/). The possible answers indicate with a "+" or a "-" whether -galactosidase would be expected to be produced at induced levels under two circumstances: 1) first in the absence of lactose and 2) second in the presence of lactose. (Assume that glucose is not present in the medium.) Genotype H: Is Oc Z-/ F' Is O+ Z+ KEY +- wild-type repressor I.“ mutant repressor (unable to bind to theExplanation / Answer
Ic is the super-repressor which cannot bind to lactose when lactose is present in the cells
Oc is the mutated operator on which either normal repressor or super-repressor cannot bind.
1- When lactose is not present in the cells- super-repressor cannot bind to the operator region of the cell, a cell has Oc which prevents repressor binding to the operator region. There is the mutation in LacZ gene so there will not be any production of Beta-galactosidases from the cell's operon. Ic can bind to the plasmid's operator and prevent the synthesis of Galactosidase from the plasmid's operon.
Answer is "-"
2- When lactose is present in the cells- super-repressor cannot bind to the operator region of the cell, the cell has Oc which prevents repressor binding to the operator region. There is the mutation in LacZ gene so there will not be any production of Beta-galactosidases from the cell's operon. Even though lactose is present in the cell, lactose cannot bind Ic, so no of Galactosidase from the plasmid's operon.
Answer is "-"
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