Concept explainers
To review:
The rotation of an image due to magnification in electron microscopy.
Introduction:
Electron microscopy utilizes a beam of electrons instead of a light source. This beam is generated by the formation of high voltage from a magnet that serves as the lens. There are various forms of electron microscopy that are different in several aspects and hence, their resolution powers and effective areas may also vary.
Electron microscopy utilizes an electron beam from an electron source that is projected onto the specimen to be studied. The electron source could be a tungsten filament and the flow of electrons is generated by a high flow of electrons due to the generation of a high voltage in the source. This is accomplished by a magnetic field. The creation of magnetic field focuses on the flow of electrons analogous to the light flowing from a source in a normal microscope.
The magnetic field is thus evident in aligning the electrons as a beam. The beam of electrons spirals as soon as it enters the field because of the influence of the magnetic field lines. This spiral motion of the beam increases or decreases with the magnetic field. The magnetic field fluctuates according to the magnification. Alteration in the spiral motion of the electron beam results in the rotation of the image.
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Chapter 2 Solutions
Microbiology: An Evolving Science (Fourth Edition)
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- The magnification possible with any type of microscope is an important property, but its resolution, the ability to distinguish between two very closely apposed objects, is even more critical. Describe why the resolving power of a microscope is more important for seeing finer details than its magnification.arrow_forwardHow many types of objective lenses a light microscope has?arrow_forwardUsing the microscope Answer the following questions as you work through this exercise: 1. How is the letter “e” on the slide oriented when you see it with the naked eye as you mount it on the stage (i.e., is it right side up or upside down)? 2. How is the letter “e” on the slide oriented when you see it under low or high power magnification? 3. What effect, if any, does the compound light microscope have on the orientation of the image?arrow_forward
- When focusing a light microscope, why is it best to adjust the focus using the coarse focusing knob before using the fine focusing knob?arrow_forwardAssume you are observing the diatom pictured in Figure 1 using the 10X lens in a compound light microscope. You move to the 40X lens and then again to the 100X lens by only rotating the turret (remember that the lenses are parfocal), without making any other adjustments to the microscope. At 100X you are unable to see the diatom. Explain why. Explain what correction (s) should be made to allow you to see the diatom using the 100X lens. After making your adjustments, you notice that the midline of the diatom is in focus while the remainder is blurry. Explain, based on microscopy principles, why this has occurred.arrow_forwardAssume you are observing the diatom pictured in Figure 1 using the 10X lens in a compound light microscope. You move to the 40X lens and then again to the 100X lens by only rotating the turret (remember that the lenses are parfocal), without making any other adjustments to the microscope. c) After making your adjustments, you notice that the midline of the diatom is in focus while the remainder is blurry. Explain, based on microscopy principles, why this has occurred Provide a description of the procedure to prepare an acidic stain of bacteria using Nigrosin as it would appear in the Methods section.arrow_forward
- Using a good compound light microscope with a resolving of 0.3 micro meter a 10x ocular lens ,and a 100 x oil immersion lens, would you be able to discern two objects separated by 0.4 micro meter?0.2 micro meter? 300 neno meter ? Explain your reasoning.arrow_forwardIn the virtual microscope lab, the simulation made you add something to the slide before you could move it to the highest power. What did you have to add?arrow_forwardWhy is the resolution so superior in the electron microscope?arrow_forward
Concepts of BiologyBiologyISBN:9781938168116Author:Samantha Fowler, Rebecca Roush, James WisePublisher:OpenStax College