Cellular Biology Exam #1 QUESTIONS WITH COMPLETE SOLUTIONS

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The feature that most clearly separates eukaryotes from prokaryotes is the presence of eukaryotic cells. Correct Answer: The nucleus. In fluorescence microscopy, the immediate source of the light ... detected is light that has been _____ the sample. Correct Answer: Emitted by. Transmission electron microscopy is used to Correct Answer: Observe subcellular organelles & macromolecules. Which of the following are the most commonly used mammals for genetic studies? Correct Answer: Mice The original cell was thought to have arisen from the self-replicating _____ by a phospholipid membrane. Correct Answer: RNA The genome of eukaryotes consists of genes derived from Correct Answer: Both archaebacteria & eubacteria. Bacteriophages are Correct Answer: Viruses that infect bacteria. In visualizing protein localization within a cell, what are the relative advantages & disadvantages of tagging proteins with green fluorescent protein (GFP) versus using a fluorescent antibody specific to the protein of interest (immunofluorescence)? Correct Answer: The main advantage of using GFP-tagged protein is that fixing, which kills cells & cause artifactual results, is not required. This makes it possible to observe subcellular localization in live cells. The localization of GFP-tagged proteins can be observed in real time in response to various inducers by infusing them into the sample while on the microscope. One potential disadvantage of using GFP-tagged proteins is that the presence of the GFP tag (which has a size of approximately 30 kilodaltons) could alter the structure of the protein and give artifactual results. In fact, that sometimes occurs. The most abundant molecule in cell is Correct Answer: Water Lipids with unsaturated fatty acids Correct Answer: Increase the fluidity of membranes What is the effect of a beta-barrel on the permeability of a membrane? Correct Answer: It increases permeability. Whereas small uncharged molecules can diffuse through the hydrophobic core of a phospholipid bilayer, a larger polar su [Show More]

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