What would be the phenotype of a bacterial cell with a loss of function mutation in the lac operon promoter?
a. The lac genes would be expressed efficiently only in the absence of lactose
b. The lac genes would be expressed efficiently only in the presence of lactose
c. The lac genes would be expressed continuously
d. The lac genes would never be expressed efficiently
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If there was a mutant that showed constitutive expression of the lac operon, and there is still functional lac repressor protein present in the cell, what is the likely location of the mutation?
Which of the following is true regarding prokaryotic operons?
You discover a mutant strain of E.coli such that it cannot grow when lactose is present in the environment. Where might this mutation be?
You have a strain of E.coil and identify that it has a mutation is its lac operator sequence such that the lac repressor can no longer bind. What would you expect would happen to the level of B-galactosidase in the cell if lactose is absent and glucose in present?
In which situation would the CAP protein be bound to the lac promoter?
How does CAP induce expression of the genes in the lac operon?
Which of the following accurately describe what happens when a bacterial cell is grown in the presence of lactose only?
Which of the following are accurate statements describing a direct interaction between a nucleic acid sequence and a protein? - Practice Question
Which of the following are accurate statements describing a direct interaction between a nucleic acid sequence and a protein?
In bacteria, a repressor protein binds to the lac operon when cells are grown in the presence of...
The following are the genotypes of partial diploid bacteria, mutant in one or more genes associated with the LAC OPERON. For each bacterium, indicate in the spaces provided whether beta-galactosidase and whether permease will be produced under conditions when lactose is present and when lactose is absent. Use "yes" to indicate that the enzyme is produced (in functional form); use "no" to indicate that the enzyme either is not produced or is not functional.
For the following table, predict the expression parent on the respective enzymes. Use the following symbols: " - " no protein product, " + " some protein product, " +++ " a lot of proteins produced.
The following are the genotypes of partial diploid bacteria, mutant in one or more genes associated with the LAC OPERON. For each bacterium, choose from the choices provided whether beta-galactosidase and whether permease will be produced under conditions when lactose is present and when lactose is absent in accordance to the table below.
Lac Operon
tRNA and the start codon
RNA polymerase and a gene promoter