Transmission Electron microscope Objective Question

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

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