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Which of the following best describes the role of codons in eukaryotic cells?

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Which one of these schemata best fits the initiation of translation in Eukaryotes?

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Which of the following is responsible for determining the amino acid sequence of a protein being synthesized by a ribosome.

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The following piece of DNA codes for an mRNA. The top strand is the template strand. The initiation and termination codons are in the sequence. שלוש'-AATTACCATGAAATTGTCATCTACTTGTTGATTA-חמש' חמש'-TTAATGGTACTTTAACAGTAGATGAACAACTAAT-שלוש' The sequence of the protein encoded by this transcript is:

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You have identified a mutation in a gene transcribed in the liver. At codon 42 of the expected translation product you find 5'-CAT-3' instead of the normal codon 5'-GAT-3'. This same mutation is found associated with type II diabetes in a large kindred. Which of the following best describes the effect of this change on the protein encoded?

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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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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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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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The homeodomain is:

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Trp A to Trp E of the trp operon (above) regulate the production of enzymes needed for the biosynthesis of tryptophan in E. coli. A single mutation in the promoter region (Ptrp) abolishes the production of all five enzymes. Which of the following mechanisms best explains the effect of this mutation?

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