-Sex pilus -Flagellum -Pili (fimbriae) (a) 2 µm Epithelial cell -Bacterium -Bacterium with pili (b) 5 μη FIGURE 3.41 Pili (a) Pili on an Escherichia coli cell. The short pili (fimbriae) allow adherence; the sex pilus is involved in DNA transfer (SEM). (b) Escherichia coli attaching to epithelial cells in the small intestine of a pig (TEM).

-Sex pilus -Flagellum -Pili (fimbriae) (a) 2 µm Epithelial cell -Bacterium -Bacterium with pili (b) 5 μη FIGURE 3.41 Pili (a) Pili on an Escherichia coli cell. The short pili (fimbriae) allow adherence; the sex pilus is involved in DNA transfer (SEM). (b) Escherichia coli attaching to epithelial cells in the small intestine of a pig (TEM).

Concepts of Biology

1st Edition

ISBN:9781938168116

Author:Samantha Fowler, Rebecca Roush, James Wise

Publisher:Samantha Fowler, Rebecca Roush, James Wise

Chapter13: Diversity Of Microbes, Fungi, And Protists

Section: Chapter Questions

Problem 1ACQ: Figure 13.6 Which of the following statements is true? a. Gram-positive bacteria have a single cell...

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(52) During the development of a new vaccine , an investigator generates a mutant strain of bacteria that does not adhere to mucosal epithelia in which of the following bacterial components or structures would most likely prevent bacterial adhesion? (A) Capsules (B) Flagella (C) Lipopolysaccharide (D) Lipotelchoic acid (E) Piii (F) Porins (G) Siderophores (H) Spores
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HersheyChase Experiments The graph shown in FIGURE 8.5 is reproduced from an original 1952 publication by Hershey and Chase. Bacteriophage were labeled with radioactive tracers and allowed 10 infect bacteria. The virusbacteria mixtures were then whirled in a blender to dislodge any viral components attached to the exterior of the bacteria. Afterward, radioactivity from the tracers was measured. FIGURE 8.5 Detail of Alfred Hershey and Martha Chases 1952 publication describing their experiments with bacteriophage. Infected bacteria refers to the percentage of bacteria that survived the blender. How did the researchers know that the radioisotopes in the fluid came from outside of the bacterial cells and not from bacteria that had been broken apart by whirling in the blender?
HersheyChase Experiments The graph shown in FIGURE 8.5 is reproduced from an original 1952 publication by Hershey and Chase. Bacteriophage were labeled with radioactive tracers and allowed 10 infect bacteria. The virusbacteria mixtures were then whirled in a blender to dislodge any viral components attached to the exterior of the bacteria. Afterward, radioactivity from the tracers was measured. FIGURE 8.5 Detail of Alfred Hershey and Martha Chases 1952 publication describing their experiments with bacteriophage. Infected bacteria refers to the percentage of bacteria that survived the blender. After 4 minutes in the blender, what percentage of each isotope was extracellular?