Name ________________________ BIO 2110 – Genetics Exam 1 2 October 2015 see last page for potentially useless figuresBIO 2110 Exam 1 Name ______________________ 2 October 2015 1. Below are diagrams of the cell cycle and of condensed chromosomes. In which stage(s) of the cell cycle would condensed chromosomes be observed? How would the structure of the chromosomes be differed in other stages of the cell cycle? What is the functional significance of these structural differences (i.e. why the differences)?BIO 2110 Exam 1 Name ______________________ 2 October 2015 2. Below is an electron micrograph of 10 nm fibers of chromatin. These fibers are referred to as beads on a string. Describe the chromatin structures that are referred to as the beads and as the string. Include in your description the components of the beads and string. In intact chromatin, how would acetylation of the ‘beads’ impact chromatin structure?BIO 2110 Exam 1 Name ______________________ 2 October 2015 3. Using lines and arrows, draw and label a diagram of a eukaryotic protein-coding gene. In your diagram, include introns, enhancers, exons, and the promoter. Describe the functions of each of these components.BIO 2110 Exam 1 Name ______________________ 2 October 2015 4. Describe the roles of TFIID and TFIIH in eukaryotic transcription initiation.BIO 2110 Exam 1 Name ______________________ 2 October 2015 5. The C-terminal domain of RNA polymerase II contains multiple repeats of the amino acid sequence YSPTSPS. Which of these amino acid residues get phosphorylated during pol II transcription? At what stage(s) of transcription do these phosphorylation events take place. What is the role of these phosphorylation events in transcription initiation and RNA processing? Y = tyrosine S = serine P = proline T = threonineBIO 2110 Exam 1 Name ______________________ 2 October 2015 6. In eukaryotes, polyadenylation and transcription termination are mechanistically linked. Describe the mechanisms by which polyadenylation causes termination.BIO 2110 Exam 1 Name ______________________ 2 October 2015 7. Describe the structure 5’ cap of eukaryotic mRNAs. Describe the roles of the 5’ cap in mRNA stability and translation.BIO 2110 Exam 1 Name ______________________ 2 October 2015 8. Provide a mechanistic description of the role of methionyl-tRNA in translation initiation.BIO 2110 Exam 1 Name ______________________ 2 October 2015 9. An amber suppressor is a mutation in a tRNA gene that allows it to insert an amino acid when it encounters a UAG stop codon. What mutation would change a glutamine (gln) tRNA into an amber suppressor? [see last page for potentially useful information]BIO 2110 Exam 1 Name ______________________ 2 October 2015 10. miRISCs associate with and down-regulate the translation of specific mRNAs. How is this specificity achieved? Describe the interactions between mRNAs and polyA tails and describe how these interactions are involved in down-regulation of
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