In a bacterial cell with the genotype I-: P+: O+: Z+: Y+: A+, which of the following expression patterns of the lac operon would you see? (All + signs designate functional units and - signs designate non-functional units) A. No expression of Z, Y and A under any environmental conditions. B. Z, Y and A would always be expressed. C. Z, Y and A would be expressed when lactose was present but not expressed if lactose is not present. D. Z, Y and A would be expressed in the absence of lactose, but not when lactose was present. E. None of the above.

The fictional bacteria Plumbumbacter aurus converts the lead ions to gold ions and uses the resulting electrons to create ATP. aurus has the midas operon which includes the promoter (midasP), the operator (midasO), and eight genes that encode proteins involved in converting lead to gold. The midas operon is regulated by the protein encoded by the midasR gene and the presence of gold ions. When the concentration of gold ions is low, the midas operon is transcribed and the bacteria convert lead into gold. When the concentration of gold is high, the midas operon is off. To better understand regulation of the midas operon, you created P. aurus mutants. The midasR- mutant has a nonfunctional midasR, the midasO- mutant has a nonfunctional midasO, and the midasP-mutant has a nonfunctional midasP. Based on the data below, the midas operon has what type of transcription control? (negative inducible, negative repressible, positive inducible, positive repressible)  Strain Produces Gold in…

A sample of E.coli cells is transformed with a plasmid containing a transcriptional fusion including the promoter of an E.coli housekeeping gene and the LacZ gene. The transformed cells are plated out on selective medium containing X-gal. Which of the following best describes the likely results. a. Colonies will only be blue if lactose is also included in the growth medium. b. Colonies will only be blue if lactose and glucose are included in the growth medium c. Most of the colonies should turn blue. d. Presence of any white colonies may indicate deletion or mutation of the promoter. e. Both c. and d. are correct

For each of the following types of transcriptional control, indicate whether the protein produced by the regulator gene will be synthesized initially as an active repressor or as an inactive repressor. a. Negative control in a repressible operon b. Negative control in an inducible operon

Based on the partial diploid sketched shown in Figure 3, where cross-hatched rectangles and the red bar indicate mutations that inactivate that particular genetic element of the operon, state if expression of Lacl (Lac repressor) and LacZ (Beta-Galactosidase) is (select one of the options below for each genetic element and briefly justify your answer): constitutively ON (in the presence/absence of lactose) constitutively OFF (in the presence/absence of lactose) • inducible by lactose • not enough information given to conclude • none of the above FIGURE 3: lacl laco lacz- lacY lacl laco lacz lacY

Explain Please

There is a mutation in sequence of the lac operator that prevents the lac repressor from being able to recognize and bind to it. What would the status of transcription of the lac operon be under each of the following circumstances? Explain your answers.   a-Lactose present, glucose present b-Lactose present, glucose absent   c-Lactose absent, glucose present   d-Lactose absent, glucose absent

For a lac operon of genotype l'POʻ*, functional beta-galactosidase is ... (pick the best answer) Select one: O a. Never produced O b. Constitutively produced O c. Under inducible control

There is Hyaluronic acid synthesis occuring in Group X Strep and it is controlled by an operon with 3 genes, called hasXYZ. Based on the 3-line diagram model,  a. How many ribosome binding sites are there for the protein? b. How many promoters are there for the genes? c. How many start codons are there for the protein? d. How many RNA Polymerase binding locations are there for the genes? e. How many proteins will be fully functional? f. How many mRNA strands are made?

A constitutive mutation in the lac operon may be of several types. [Note that constitutive means that the structural genes are always expressed, even if lactose is absent.] Name two types of constitutive mutations. Group of answer choices LacY- and LacI- LacOc and LacZ- LacZ- and LacI- LacY- and LacA- LacI- and LacOc