Question

Part II. Short Answers @ 1pts each. Write your answers directly on the s on the test. spaces provided 31. In lecture, we described many cell structures that enhance an organism's virulence. virulent cell structures? Why is the ability to form an endospore the most significant of all You have isolated a bacterium from the bottom from a deep ocean trench in a tropical location. Provide scientific term that would describe its physical or chemical requirements 32. 33. Which form of microscopy would be best to use if you wanted to determine which bacteria had specific proteins on their cell wall from those that do not have it. In lecture, we described flagella and axial filaments as "cell motors". While they both help the cell move, the do so differently. Functionally, how are flagella and axial filaments different? 34. Serial Endosymbiosis Theory (SET) has two general bodies of evidence that support it and one body of evidence that did not. Provide one specific line of evidence that SUPPORTS this theory 35. Choose the answer that completes the following statement. Electrons have a shorter wavelength than light microscopes. As a result, microscopes using electrons as their energy source have (higher, lower, or about the same) resolution. 36. 37. True or False. All bacteria require oxygen in order to survive.

Answer 1

31. Endospore is formed by some bacteria under stress conditions. Endospore is a tough structure that protects bacteria for long duration from dessication. Bacteria that can form endospore , are resistant to extreme temperatures, dryness, excess moisture and all the other adverse environmental conditions that generally are sufficient to kill the bacteria and end their virulence. So, the ability to form endospore is significant because the endospore coats the bacteria and ensure its survival under stress conditions for long periods of time. After the stress period is over, bacteria again can start growing, reproducing and can again become equally virulent as was earlier.

33. Scanning electron microscopy would be best to differentiate between two bacteria on the basis of surface proteins. Scanning electron microscope scans the surface (example cell wall of bacteria) on which the beam of electron is focused an the image is formed by interaction of electron with the atom of the surface.

36. Microscopes using electrons as their energy source have higher resolution. Wavelength and resolution are inversely proportional to each other that is, shorter the wavelength higher the resolution.

37. False. Not all bacteria require oxygen to survive. In fact many are anaerobic(obligate or facultative). Example: E.coli , the commonly used model bacteria in research field, is facultative anaerobic microorganism that can survive and grow in the absence of oxygen. Clostridium botulinum is another example of anaerobically(obligate) growing bacteria.