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You transfer wildtype E.coli from plates containing lactose to plates containing both glucose and lactose. Under these conditions indicate what sequence of events will occur at the lac operon promoter.

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In the context of prokaryotic gene regulation, an operator is the:

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TBP, the TATA Binding Protein:

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(USMLoid) The VHL gene is often mutated in people suffering from von Hippel-Lindau (VHL) disease. The VHL protein is found in a ubiquitin-ligase complex that targets the transcription factor Hypoxia Inducible Factor 1 (HIF-1). In VHL patients HIF-1 is not targeted for destruction by the ubiquitination pathway. Which of the following genes will most likely show increased gene expression as a result?

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The key to answering this question is not to remember the pathways, but simply to build the sensible association between hypoxia and a need for more blood vessels. That leads you directly to the VEGF receptor. That simple.
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(USMLoid) A researcher has identified a gene of unknown function by linkage analysis in an extended family showing early onset Alzheimer dementia. While characterising the regulation of this gene in a transgenic cell-culture system the researcher has focussed on a 860 bp sequence located 2,412 bp before the start of transcription. When it is removed, expression of the gene decreases 30-fold. When it is put back in either orientation, the expression is restored. Which of the following best defines this sequence?

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(USMLoid) Sequencing the factor IX gene of a 12-year old hemophilia patient shows a T->G point mutation 20 base-pairs before the first exon of the gene. This is most likely to disrupt the binding of which of the following?

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(USMLoid) Transcription in eukaryotes is often regulated by promoter sequence and enhancer elements. Which of the following best describes enhancers?

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What is the homeodomain?

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5. contains the serine protease active site.

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here are the regulatory regions of genes encoding Y and ΔY (top). You have cells which express the steroid hormone (X) receptor (Xrec) under the control of a constitutive promoter. Hormone-bound Xrec is a transcription activator binding to its recognition sequence XrecBS. The transcription factor Y contains a DNA-binding domain at the amino terminus that recognizes the sequence YBS and a c-terminus polyglutamine sequence. The transcription factor ΔY is the same as Y, but is missing the c-terminus polyglutamine sequence. The relative half-lives of X, Y, and ΔY are as follows t½X = 5, t½Y = 5, t½ΔY = 15. Which of the graphs best describes the rate of transcription from the Y promoter after the addition of hormone X at the time indicated? Select one:

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