What experimental results would indicate that the mutation lacISlacIS is dominant to lacI+lacI+?   In lacISlacIS/lacI+lacI+ partial diploids, the lac operon is in a repressed state in the absence of lactose. In lacISlacIS/lacI+lacI+ partial diploids, the lac operon is in a constitutive state in the absence of the repressor. In lacISlacIS/lacI+lacI+ partial diploids, the lac operon is in an activated state in the presence of lactose. In lacISlacIS/lacI+lacI+ partial diploids, the lac operon is in a repressed state in the absence of the repressor. In lacISlacIS/lacI+lacI+ partial diploids, the lac operon is in a repressed state in the presence of lactose

The trp operon in E. coli encodes enzymes essential for the biosynthesis of tryptophan. In the operon, trpR gene encodes the repressor. A trpR repressor cannot bind tryptophan. The trpO is the operator. trpA encodes the enzyme tryptophan synthetase. For the enzyme (A), indicate with a + or-whether or not it is made when there is tryptophan and when there is no tryptophan. Without Tryptophan With Tryptophan R'O A /R* O' A R'O' A/R* Oʻ A R*OA/R' O A

A mutant E. coli strain is isolated which does not ever produce the enzymes β-galactosidase or permease, irrespective of whether lactose is present or absent. If the normal wild-type genotype with respect to the lac operon can be represented as lacI+ lacP+ lacO+ lacZ+ lacY+, give three different mutant genotypes (list all 5 operon components in each case, do not consider partial diploids) which would result in the mutant phenotype described here.

Which of the following lac operon genotypes would allow for functional versions of all the structural enzymes of the lac operon to be expressed constitutively even in the absence of lactose?   Group of answer choices I+ O+ Z+ Y+ A+ I- O+ Z- Y- A- I+ OC Z+ Y+ A+ IS O+ Z+ Y+ A+ I+ O+ Z- Y+ A+

The L-arabinose operon, also called ara, is an operon required to break down the sugar L-arabinose in E. coli. This operon contains 3 structural genes in the following order, araB, araA, araD and expression is controlled by the product of a repressor called araC and the CAP protein which is regulated by cAMP in the same way as it is for the lactose operon.   Now Draw a schematic of what this operon might look like when glucose levels are low and arabinose levels are high. Include the relevant proteins and their effector molecules, the promoter, operator, and structural genes. Note if the operon is being transcribed or not.

In the lac operon (below), how will expression of the genes lacZ and lacy be effect by a mutation in the repressor protein (encoded by lach) that prevents it from binding the operator sequence (lacO) in the absence of lactose? Explain the answer

Determine the outcome for the lac operon genotype shown below: I*p*o°z*y/I*p*o*z*x* Assume lactose is absent. Select one: O Functional beta-galactosidase and functional permease are produced. O Only functional beta-galactosidase is produced. Functional permease is NOT produced. O Only functional permease is produced. Functional beta-galactosidase is NOT produced. O Functional beta-galactosidase is NOT produced. Functional permease is NOT produced.

To characterize the promoter of the gadA operon you made a series of deletion mutants removing pieces of the promoter to see what would happen. The results are found below: gad promoter gada gadX gadz 450 +1 lacz activity transcription start site pH 2.0 pH 7.0 A gad promoter beta-galactosidase (lacZ) +++ 450 gad promoter beta galactosidase (lacZ) +++ +++ 300 +1 gad promoter beta galactosidase (lacZ) 150 D gad beta galactosidase (lacz) -450 150 E gad promoter beta-galactosidase (lacZ) -450 -300 Based on these results, what can you conclude about the gad promoter? O a. The promoter is only regulated by repression Ob. The promoter is regulated by a mix of activation and repression O c. The promoter is only regulated by activation O d. The promoter has multiple operators and multiple enhancers

The streptolysin S toxin made by S. pyogenes is encoded by a 9-gene operon, sagABCDEFGHI. Thinking about what a 3-line diagram would look like for this operon, answer the following questions. Write numeric answers only. For example, if your answer is 6 promoters, write only 6. 1) How many promoters control the expression of these genes? 2) How many locations does RNA Polymerase bind to get full expression of these genes? 3) How many ribosome binding sites are needed for full protein expression? 4) How many start codons will be needed for full protein expression? 5) How many mRNA strands will be produced with full operon expression? 6) How many proteins will be produced with full protein expression? 1

The L-arabinose operon, also called ara, is an operon required to break down the sugar L-arabinose in E. coli. This operon contains 3 structural genes in the following order, araB, araA, araD and expression is controlled by the product of a repressor called araC and the CAP protein which is regulated by cAMP in the same way as it is for the lactose operon. From the available information here, draw a schematic of what this operon might look like when glucose levels are low and arabinose levels are high. Include the relevant proteins and their effector molecules, the promoter, operator, and structural genes. Note if the operon is being transcribed or not.