NAME NETWORK ID SECTION TA MCB 252 Exam I February 16 2016 Form A This exam consists of 59 questions for a total of 175 points Choose the BEST answer from the available choices Questions 1 10 are worth 2 points each Decide whether the following statements are TRUE or FALSE 1 During nucleo cytoplasmic transport of proteins the translocation step through the channel of the nuclear pore complex is powered by ATP hydrolysis A TRUE B FALSE 2 A protein that contains a chromodomain is likely a reader of the histone code A TRUE B FALSE 3 Pre lamin A is not farnesylated but wild type mature lamin A is farnesylated A TRUE B FALSE 4 As discussed in lecture recent evidence suggests but does not prove that the original Ras family members played a role in cell division A TRUE B FALSE 5 Many types of cells need to receive signals in order to stay alive A TRUE B FALSE Page 1 of 16 6 Signaling molecules ligands can be can be proteins peptides amino acids nucleotides steroids fatty acid derivatives or even gases A TRUE B FALSE 7 At least some exportins are part of a superfamily that contains importins A TRUE B FALSE 8 Prenylation of RAS only occurs under conditions in which the RAS pathway is active A TRUE B FALSE 9 As described in lecture there are at least three different isoforms of nuclear pore complexes A TRUE B FALSE 10 As described in lecture dominant negative mutant proteins interfere with the function of one or more wild type proteins A TRUE B FALSE Questions 11 55 are worth 3 points each 11 Which of the following best describes how heterochromatin is localized to the nuclear periphery A Heterochromatin proteins bind to proteins that are trans membrane proteins of the inner nuclear membrane or bind to proteins that are bound to transmembrane proteins of the inner nuclear membrane and are thereby tethered to the nuclear periphery B Unfolding of euchromatin pushes the more highly condensed heterochromatin to the edges of the nucleus C Motor proteins move heterochromatin away from the center of the nucleus to the periphery D Both A and B E All of the above A B and C Page 2 of 16 12 The CDT tail that plays a role in 5 G methyl capping of the transcript and elongation is part of which protein or protein complex A A GTF B Mediator C A transcription factor D A co activator E RNA polymerase II 13 You are studying a 200 kD protein that functions exclusively as a monomer You generate a GFP fusion to your protein and visualize it s location by fluorescence microscopy You find that the protein is located in the cytoplasm but not the nucleus You next create a GFP fusion to a version of your protein that lacks 10 amino acids near the N terminus of your protein and visualize it s location by fluorescence microscopy You find that this version of your protein is now localized in the nucleus but not the cytoplasm Which hypothesis can account for your results A The wild type version of your protein contains an NLS and a KEN box B The wild type version of your protein contains an NES and a KEN box C The wild type version of your protein contains an NLS but not an NES D The wild type version of your protein contains an NES but not an NLS E The wild type version of your protein contains both an NLS and an NES 14 In lecture we discussed the idea that the activity of a gene could be potentially regulated at many different steps including transcription RNA processing RNA transport RNA degradation translation and post translational control of protein activity In general transcriptional control makes sense in many most cases because it saves the most energy Consider a cell that can respond to a particular signal In that cell most of the proteins on the signal transduction pathway that transmit that particular signal are regulated at which step A Transcription B RNA processing C Nucleo cytoplasmic transport D Translation E Post translational control of protein activity 15 Which of the following pathways is reset shut off most rapidly A The RAS pathway B The NFKB pathway C A pathway that is activated by photons D A pathway that responds to a steroid hormone E The pathway that leads to mating of yeast cells Page 3 of 16 Refer to the figure below for the next two questions 16 What type of technique procedure experiment is shown in the figure above A Ion Exchange Chromatography B Gel Filtration Chromatography C Mass Chromatography D Mass Spectometry E A Genetic Screen 17 Which fractions should be pooled together and subjected to further study A The fractions labeled A B The fractions labeled B C The fractions labeled C D The fractions labeled D E The fractions labeled E 18 Which of the following allows visualization of protein dynamics in living cells A B C D E Expression of GFP fusion proteins Immuno fluorescence DAPI staining Both A and B All of the above A B and C Page 4 of 16 19 You are studying a particular type of cancer You have performed a series of experiments that lead you to believe that a mutation in MEK contributes to cancer You have developed a drug that inhibits the function of RAS and as a result is an effective chemotherapy drug for some types of cancer Would you expect this drug to be an effective chemotherapy drug for the type of cancer you are studying A Yes the drug would be expected to be effective against the type of cancer you are studying B No the drug would not be expected to be effective against the type of cancer you are studying 20 Which protein binds to proteins that contain an NES A B C D E RCC1 CAS CRM1 LMB Ran GDP 21 Approximately how many RAS family members or superfamily members are there in humans A 16 B 32 C 160 D 320 E 1 600 22 The retinoblastoma gene Rb is a gene commonly mutated in human cancers For mutations in Rb to contribute to cancer both copies must be mutated Based on this information choose the best answer A Rb is most likely an oncogene in which a gain of function mutation s contribute to cancer B Rb is most likely an oncogene in which a loss of function mutation s contribute to cancer C Rb is most likely a tumor suppressor in which a gain of function mutation s contribute to cancer D Rb is most likely a tumor suppressor in which a loss of function mutation s contribute to cancer Page 5 of 16 23 Approximately how many distinct cells types are there in humans A 5 B 63 C 98 D 210 E 512 24 You have found an epithelial cell line that proliferates rapidly even in the absence of EGF which is usually required to cause cultured epithelial cell proliferation Which of the