BIOD 171 Microbiology Exam 3 Portage learning 2024

micrometer one millionth of a meter, 10^ -6 2. nanometer one billionth of a meter, 10^-9 3. Resolution the distance between two objects at which the objects still can be seen as separate 4. What happens if the resolution is poor? Poor or low resolution means two (or more) objects may appear as one. 5. Contrast the difference in light absorbance between two objects. 6. What happens if there is poor contrast? gives a high background and makes the visualization of multiple objects difficult. 7. If you wish to increase the amount of light going into a microscope, what part would you adjust? The iris diaphragm 8. As light passes through a microscope, what is the last piece that light passes before reaching your eyes? the ocular lens, or eyepiece, directly into your eye. 9. How is the total magnification of an object calculated? Total magnification is calculated by multiplying the power of the objective and the power of the eyepiece. 10. What is one limitation of fixing your sample? Fixation requires you to irreversibly kill your sample. Thus, determining the motility (cell movement) of a sample is impossible. Fixation also runs the risk of distorting the specimen shape and arrangement. 11. Phase-contrast microscopy provided what benefits to imaging? Phase-contrast microscope can provide detailed images of live cells without staining. Able to visualize certain structures that would otherwise be invisible