A partial diploid E. coli cell was created with the following genotype: it pozi yt / pf oʻzty Under which conditions would both beta-galactosidase and permease be produced? A Both beta-galactosidase and permease will be made constitutively, since one DNA strand has a mutant operator and therefore cannot be repressed by the lac repressor. B. The only conditions where this will happen are low glucose and high lactose levels. C. There won't be any conditions in which both beta-galactosidase and permease are made, since the lacy gene on the strand of DNA with a functional promoter is mutant. D. Neither beta-galactosidase nor permease will ever be produced, because the super repressor will always bind the operator to prevent transcription of lacZ and lacy.

Question

Biology

Mireya Hahn

8 November, 16:22

A partial diploid E. coli cell was created with the following genotype: it pozi yt / pf oʻzty Under which conditions would both beta-galactosidase and permease be produced? A Both beta-galactosidase and permease will be made constitutively, since one DNA strand has a mutant operator and therefore cannot be repressed by the lac repressor. B. The only conditions where this will happen are low glucose and high lactose levels. C. There won't be any conditions in which both beta-galactosidase and permease are made, since the lacy gene on the strand of DNA with a functional promoter is mutant. D. Neither beta-galactosidase nor permease will ever be produced, because the super repressor will always bind the operator to prevent transcription of lacZ and lacy.

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Answers (1)

Know the Answer?

Chad Hutchinson · Answer 1

the answer is c

c) There won't be any conditions in which both beta-galactosidase and permease are made, since the lacy gene on the strand of DNA with a functional promoter is mutant.

Explanation:

As per the given data the first strand does not have the promoter (p-). so RNA polymerase cannot bind to that strand to make any transcript. Then coming to the second strand, it does not have a Lac Y gene (Y-). Though the presence of super repressor has no effect on operator (o-), it can no longer bind to the operator, the genes would be expressed continuously but, lac y gene expression wont be there.

so the answer is option c There won't be any conditions in which both beta-galactosidase and permease are made, since the lacy gene on the strand of DNA with a functional promoter is mutant.