Given that I- is a mutation that eliminates the production of the repressor, this means that the structural genes will be transcribed even if lactose is absent. The repressor binds to the operator and prevents the transcription of genes for lactose metabolism when lactose is absent. The repressor does not bind to the operator when lactose is present.
In the case of mutation where the repressor itself is absent, then the operon would work irrespective of the presence or absence of lactose. But, since there is another mutation (Pc) where the polymerase that transcribes the genes cannot bind to the promoter, there is simply no transcription of the genes. For transcription to occur, it is essential for the polymerase to bind to the promoter. And, without transcription, there is no translation of the genes either.
Therefore the right answer here is the fourth option, will not be transcribed under any conditions.
All other options would be wrong.
genetics An E. Coli strain possesses the following genotype: F(P+)/" pCo+z+y+ where l' is a mutation...
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A mutant E. coli strain is found that does not synthesize any enzymes in the presence or absence of lactose (or allolactose). W mutation(s) can lead to this outcome? The lac operon is shown here as a guide. fones where proteins bind DNA genes and regulatory sequences Operator La repressor B-galactosidase B-galactos de transactylase proteins promoter Operator Lacy Lac A laci o Lacz
The diagram below illustrates the LAC operon in its OFF state when the inducer molecule —lactose—is absent. Predict the ways in which the following conditions will affect the transcription of the lactose-utilization genes. OPERON Regulatory Promoter Operator_ gene Lactose-utilization genes DNA mRNA RNA polymerase cannot attach to promoter Active repressor Protein If a mutation in the regulatory gene results in a misfolding of the repressor protein so that it can no longer bind DNA, the lactose-utilization genes O Will be...
20862a a A mutant E. coli strain is found that does not synthesize any enzymes in the presence or absence of lactose for allolactose). What mutation(s) can lead to this outcome? The lac operon is shown here as a guide. ones where proteins bind DNA genes and regulatory sequences och Operator o Lacy o Lacz o Laca promoter MacBook Air * जीप
A mutant E. coli strain is found that synthesizes B-galactosidase and permease but no B-galactoside-transacetylase in the presence of lactose (or allolactose). What mutation(s) can lead to this outcome? The lac operon is shown here as a guide. zones where proteins bind DNA: genes and regulatory sequences I lacl promoter operator lac Z l ac Y La repressor B-galactosidase B-galactoside transacetylase proteins Operator Laci promoter Lac Y Lac A Lacz
Note whether in the following strains of E. coli,
B-galactosidase will be:
(A) Abundant in both the presence and absence of lactose
(B) Abundant only in the absence of lactose
(C) Abundant only in the presence of lactose
(D) Abundant only in the presence of sucrose
(D) Absent in both the presence and absence of lactose
Can you answer and explain these please?
What is the correct gene order and which 2 genes are most closely linked? (4 Points) o+at...
Consider the following lac operon genotype: laci+P+OCZY+A+ In an E. coli strain with this genotype, what is the status of beta- galactosidase activity in the PRESENCE of lactose? O A. - OB. + c. Can't tell
UT EID: D. 5 E. 6 13. For the E. coli strain containing the following alleles of the lac operon, expression of lacZ and lacY is inducible, constitutively on or permanently repressed. (erepressor; r cannot bind operator: osoperator, o cannot bind repressor, lac are LOF mutations) A. lacZ is inducible, lacY is constitutively on. B. lacZ is constitutively on, lacY is inducible. C. lacZ is permanently repressed, lacY is constitutively on. D. lacZ is constitutively on, lacY is permanently repressed....
3. Consider a hypothetical strain of E. coli (strain 401) that contains two mutations that affect tryptophan biosynthesis. The first mutation is a single nucleotide substitution that converts the second tandem Trp codon in region 1 of the Trp leader sequence into a stop codon (see slides 2-7 of Lecture 24 on iLearn) trp structural genes trpE trpD trpC trpB trpA PO Trp Leader Met-Lys-Ala-lle-Phe-Val-Leu-Lys-Gly-Trp-Trp-Arg-Thr Ser- Stop Assume that strain 401 also contains a mutation in the gene for the...
There are two different strains of E. coli. One type is a wild type and the other is a lac operon mutant. The lac operon wild type has the genotype: I+P+O+Z+Y+A+ What is a silent mutation? What would be the result for the lac operon genes?