MIC 102 UC Davis Exam Questions with Correct Answers

MIC 102 UC Davis Exam Questions with Correct Answers What is a microbe? - Answer-"free-living organisms so small that they are only visible under the microscope" Are their exceptions to the definition to microbes? - Answer-Yes, some microbes are hug, not free-living, or organisms What is LUCA? And how does it relate to microbes? - Answer-Last Universal Common Ancestor is thought to be what all organisms have evolved from over 4 billion years. Specifically though, the LUCA is thought to be a microbe. Can determine relationships from the small subunit (16S) rRNA gene Name three characteristics of LUCA - Answer-The LUCA and common species today share 1) DNA as genetic material 2)Protein and RNA 3) Lipid Membrane Explain how the three domain tree is different from the ring of life. - Answer-The three domain tree groups the organisms into their three appropriate lineage (Bacteria, Archaea, and Eukarya), Each developing linearly and separating with different adaptations. Whereas a ring of life includes lineage from lateral gene transfer - the organisms are really intertwined with one another and creating new species. What are the pros and cons for microbes being small? - Answer-Pro: microbes can maintain a high surface-to-volume ratio to maximize nutrient exchange. Con: Easy targets for larger microbes/species. How does cell shape influence cell metabolism? - Answer-High surface are to volume ratio can increase metabolism of nutrients, which will in affect increase growth and reproduction. Compare and contrast the general structures of archaea, bacteria and eukaryotic bacteria. - Answer-Prokaryotics: no nucleus bacteria: have rod shaped, sphere shaped, and helixcal shapes archaea: have sphereical and rod shaped organiams Eukaryotes: have fungi, slime molds mircroscopic algae, and protozoa...Organelles include nuclus, mitcochondria, and chloroplast. Explain why cells must have a membrane - Answer-To make a selective barrier for chemical diffusion and allow the primitive biological molecules to replicate and catalyze reactions in a protected , favored environment.