1. The first Electron Microscope was devised by:
- a) Max Knoll, Ernst Ruska and Zworykin
- b) Max Knoll, Ernst Ruska and Von Andrenne
- c) J. J. Thomson, Ernst Ruska and Zworykin
- d) J. J. Thomson, Ernst Ruska and Zworykin
2. What is the correct statement about wavelength of electron?
- a) It is 1,00,000 times longer than the visible light
- b) It is 1,00,000 times shorter than the visible light
- c) It is 1000 times longer than the visible light
- d) It is 1000 times shorter than the visible light
3. Through which source electron beam is generated in TEM?
- a) Heated iron filament
- b) Liquid nitrogen
- c) Heated tungsten filament
- d) All of the above
4. What is the shape and material of magnetic glass used in TEM?
- a) Circular disc shape electromagnets
- b) Square disc shape glass lens
- c) Doughnut shape electromagnets
- d) Doughnut shape glass lens
5. Sectioning of specimen can be prepared for TEM using:
- a) Glass knife
- b) Diamond knife
- c) Ultra microtone
- d) All of the above
6. The chemical fixatives used in TEM and SEM are:
- a) Glutaraldehyde
- b) Osmium tetroxide
- c) Both a and b
- d) None of the above
7. The technique which imparts a 3-D effect to the specimen in TEM is known as:
- a) Freeze etching technique
- b) Staining technique
- c) Shadow casting technique
- d) Fluorescent technique
8. Techniques of TEM include:
- a) Preparation of the specimen
- b) Development of contrast
- c) Shadow casting technique
- d) All of the above
9. The microscope used for micro surgery is:
- a) DIC microscope
- b) Scanning Tunneling Microscope
- c) Transmission Positron Microscope
- d) All of the above
10. Equipments of an Electron Microscope includes:
- a) Electron gun
- b) Vacuum device
- c) Magnetic lenses
- d) All of the above
11. Which electrons form image in TEM?
- a) Electron passing through the specimen
- b) Electron passing outside the periphery of specimen
- c) Electron scattered from the surface of specimen
- d) All of the above
12. Which of the following is an essential requirement of TEM?
- a) Instead of glass lens magnetic lenses are used
- b) Specimen must be viewed in vacuum
- c) Extremely thin slices of specimen are required.
- d) All of the above
13. A major break-through in the studies of cells came with the development of electron microscope as:
- a) Electron microscope is more powerful than the light microscope as it uses a beam of electrons having a much longer wavelength than that of photons
- b) The resolving power of an electron microscope is much higher compared to that of a light microscope
- c) Electron beam can pass through thick materials, whereas thin sections can only be studied by a light microscope
- d) Resolving power of electron microscope is 200 – 350 nm, and that of light microscope is 0.1 – 0.2 nm
14. Which of the following is not a characteristic of TEM?
- a) It produces image of the object, due to the electron beam that passes through the specimen
- b) The specimen must be ultrathin
- c) The resolvable distance is about 1 nm
- d) Detector is necessary because the secondary electrons form the image
15. TEM technique includes:
- a) Development of contrast
- b) Shadowing
- c) Freeze etching technique
- d) All of the above
16. The first TEM was designed by:
- a) Gerd Binneng
- b) Heinrich Rohrer
- c) Ernst Ruska
- d) Roger Moore
17. The dried samples of SEM are mounted and coated with:
- a) Thin layer of agarose to prevent building up of an electric charge on the surface, and to give a better image
- b) Thin layer of metal to prevent building up of an electric charge on the surface, and to give a better image
- c) Thin layer of negatively charged stain to prevent building up of an electric charge on the surface, and to give a better image
- d) Thin layer of mordant to prevent building up of an electric charge on the surface, and to give a better image
18. In Electron microscope, the specimen is mounted on:
- a) Glass slide
- b) Polyacrylamide gel
- c) Metal grid
- d) Cellulose filter pad
19. The wavelength of electron microscope is around:
- a) 0.005 nm
- b) 0.05 nm
- c) 0.5 nm
- d) 5000 nm
20. In TEM, the specimen samples are fixed by:
- a) Titanium
- b) Ethanol
- c) Water
- d) Glutaraldehyde
21. The ions that bind to cell surface, rendering the cell more electron opaque are:
- a) Lead
- b) Sodium
- c) Silver
- d) Uranyl acetate
22. In freeze etching technique, cells are frozen in:
a) Liquid Nitrogen
b) Ice
c) Liquid C
d) Liquid Argon
23. The magnification power of a TEM is __ times higher than a Light Microscope:
a) 10
b) 100
c) 1000
d) 100000
24. The danger of artifacts is minimized by:
- a) Shadow casting
- b) Chemical fixation
- c) Freeze etching
- d) Negative staining
25. The best resolution obtained by an Electron microscope is:
- a) 0.2 µm
- b) 0.5 µm
- c) 0.2 nm
- d) 0.5 nm
26. Resolution power of an SEM is:
- a) More than 10 nm
- b) Less than 10 A°
- c) Less than 7 A°
- d) Less than 7 nm
27. The wavelength of e-beam is:
- a) 0.05 nm
- b) 0.005 nm
- c) 0.07 nm
- d) 0.05 mm
28. An Electron Gun is used to form the image of the specimen in:
- a) SEM
- b) TEM
- c) CSLM
- d) DIC
29. As electrons are unable to pass through a glass lens in electron microscope, the lens used to focus the beam is:
- a) Objective lens
- b) Magnetic lens
- c) Condenser lens
- d) None of the above
30. Which of the following is not a magnetic lens?
- a) Projector lens magnet
- b) Condenser lens magnet
- c) Objective lens magnet
- d) Tungsten lens magnet
31. In TEM, acetone and ethanol are used for dehydration in a process called:
- a) Embedding
- b) Dehydration
- c) Staining
- d) Shadowing
32. In shadowing, microorganisms are coated with a thin film of a heavy metal like platinum by the following process:
- a) Evaporation
- b) Absorption
- c) Osmosis
- d) Adsorption
33. __ metal is used to coat specimen in shadowing:
- a) Platinum
- b) Sodium
- c) Potassium
- d) All of the above
34. The probability of electron scattering in TEM is determined by __ of the specimen:
- a) Density
- b) Viscosity
- c) Clarity
- d) Hardness
35. Which of the following is the specimen preparation method for TEM?
- a) Embedding
- b) Freeze etching
- c) Shadowing
- d) All of the above
36. In TEM, to form a hard block containing specimen_________ material is used:
- a) Osmium tetroxide
- b) Epoxy plastic
- c) Acetone
- d) Glutaraldehyde
37. Which of the following structure can be particularly studied using shadowing?
- a) Virus particle morphology
- b) Bacterial flagella
- c) DNA
- d) All of the above
38. The full form of TEM is:
- a) Transmission Electron Microscope
- b) Transfer Electron Microscope
- c) Tunneling Electron Microscope
- d) Tungsten Electron Microscope
39. In Transmission Electron Microscope:
- a) Electromagnets function as lenses, and the whole system operates in a vacuum
- b) Electromagnets function as lenses, and the whole system operates in air medium
- c) Electromagnets function as prisms, and the whole system operates in a vacuum
- d) Electromagnets function as prisms, and the whole system operates in air medium
40. Electron Microscope enables us to view structures at molecular level because:
- a) The wavelength of electrons is much longer than the wavelength of visible light affecting resolution
- b) The wavelength of electrons is much shorter than the wavelength of visible light affecting resolution
- c) The wavelength of visible light is much longer than the wavelength of electrons affecting resolution
- d) The wavelength of visible light is much shorter than the wavelength of electrons affecting resolution
41. To examine a single bacterial cell by TEM, it is needed to cut a bacterial cell in:
- a) Very thin 20 to 100 nm slices
- b) Very thin 100 to 160 nm slices
- c) Very thin 160 to 180 nm slices
- d) Very thin 180 to 280 nm slices
42. Which of the following material is used to increase contrast of specimen in TEM?
- a) Uranyl acetate
- b) Lead citrate
- c) Osmium tetroxide
- d) All of the above
43. Permanganate, Uranium and Lanthanum salts are used to stain preparations in TEM because:
- a) These substances are composed of atoms of high atomic weight, they scatter electrons, and thus improve contrast
- b) These substances are composed of atoms of low atomic weight, they scatter electrons, and thus improve contrast
- c) These substances are composed of atoms of high atomic weight, they gather electrons, and thus improve contrast
- d) These substances are composed of atoms of low atomic weight, they scatter electrons, and thus improve contrast
44. Intact cells and cell components can be observed directly by TEM with a technique called:
- a) Micro-chemical staining
- b) Cytological staining
- c) Differential staining
- d) Negative staining
45. In SEM, the specimen is coated with a thin film of:
- a) Gold
- b) Silver
- c) Platinum
- d) All of the above
46. Electron micrographs taken by either TEM or SEM are:
- a) Black and white images
- b) Colored images
- c) Transparent images
- d) Opaque images
47. In TEM, the electrons directly produce the image, so:
- a) Detector is required
- b) Detector is not required
- c) Probe is required
- d) Probe is not required
48. In TEM, the resolvable distance is about:
- a) 1000 nm
- b) 100 nm
- c) 10 nm
- d) 1 nm
49. TEM is used to observe:
- a) External cell structure up to molecular level
- b) Internal cell structure up to molecular level
- c) Surface structures
- d) None of the above
50. In freeze-etching technique exposed surfaces are coated with:
- a) Platinum and carbon
- b) Carbon and chromium
- c) Chromium and platinum
- d) Tungsten
51. __ technique is particularly useful in observation of organelles within cells:
- a) Shadowing
- b) Negative staining
- c) Freeze etching
- d) All of the above
52. The freeze etching technique includes:
- a) Frozen eukaryotic cell being fractured with a cool knife
- b) Etching by sublimation of more ice
- c) Shadowing with a mixture of Platinum and Carbon to form a replica
- d) All of the above
53. The difference between TEM and Light Microscope is:
- a) TEM consists of a electron gun
- b) TEM consists of an objective and projector lens electromagnet
- c) TEM produces the final image on fluorescent screen or photographic plate
- d) All of the above
54. In electron microscope, the maximum magnification for sharpness of details is about:
- a) 150000 x
- b) 200000 x
- c) 250000 x
- d) 225000 x
55. Electron microscope can be used to obtain images of:
- a) Protein molecules
- b) Viruses
- c) Unstained flagella
- d) All of the above
56. The electron microscope uses a beam of high speed electrons having an equivalent wavelength of X-ray dimension which is about:
- a) 0.05 A° or one-fifth of a billionth of an inch
- b) 0.5 A° or one-fifth of a billionth of an inch
- c) 0.05 A° or two-fifth of a billionth of an inch
- d) 0.5 A° or two-fifth of a billionth of an inch
57. In Electron microscopy, electrons are focused by means of magnetic fields to form an enlarged image on:
- a) Fluorescent screen
- b) Photographic plate
- c) Both a and b
- d) None of the above
58. The magnetic coil could be used as lenses for Electron Microscope was suggested by:
- a) Von Borries and Ruska
- b) Von Borries and Gabor
- c) Ruska and Gabor
- d) Busch and Gabor
59. J. J. Thomson explained that the cathode is an electrode that emits a wave of:
- a) Negatively charged particles called electrons
- b) Positively charged particles called electrons
- c) Positively charged particles called positrons
- d) Negatively charged particles called neutrons
60. In an Electron Microscope, electron gun, electromagnets and fluorescent screen are arranged
in:
- a) Erect position
- b) Inverted position
- c) Slanting position
- d) Horizontal position
61. The electron gun in an Electron Microscope works at:
- a) 30 – 50 KV
- b) 3 – 5 KV
- c) 60 – 80 KV
- d) 6 – 8 KV
62. In shadow casting technique, the area coated with metal:
- a) Appears dark in photograph
- b) Appears light in photograph
- c) Appears colored in photograph
- d) Appears translucent in photograph