MIC 102 UC Davis questions with correct answers

What is a microbe? CORRECT ANSWER "free-living organisms so small that they are only visible under the microscope" Are their exceptions to the definition to microbes? CORRECT ANSWER Yes, some microbes are hug, not free-living, or organisms What is LUCA? And how does it relate to microbes? CORRECT 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 CORRECT 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. CORRECT 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? CORRECT ANSWER Pro: microbes can maintain a high surface-to-volume ratio to maximize nutrient exchange. Con: Easy targets for larger microbes/species.