Types Of Microscopy (L1)

Question 1

Microscope use/What are microscopes used for?

Answer 1

To render visible objects as details that are too small to be seen by the unaided eye.

Question 2

Resolving power (r.p.)?

Answer 2

= smallest separation at which we can see that 2 objects are present rather than one.

Question 3

Magnifying power?

Answer 3

= how many times the apparent size of the object has been increased.

Question 4

r.p. of the Human eye?

Answer 4

r.p. of 1/10mm (100μm).

Question 5

r.p. of Light microscope?

Answer 5

0.2μm (200nm).

Question 6

r.p. of Electron microscope?

Answer 6

0.2nm.

Question 7

Types of microscopes (in order of resolution & area size of specimen used)? (3)

Answer 7

• Light microscope (LM).
• Scanning electron microscope (SEM).
• Transmission electron microscope (TEM).

Question 8

Types of Light microscopes? (2)

Answer 8

• Stereobinocular microscope.
• Compound microscope.

Question 9

Stereobinocular microscope is AKA?

Answer 9

Dissecting microscope.

Question 10

Units used in Microscopy? (4)

Answer 10

• mm.
• μm.
• nm.
• pm.

Question 11

Stereobinocular microscope?

Answer 11

= microscope where light is reflected off the surface of specimen or transmitted through it.

Question 12

What is a Stereobinocular microscope used for?

Answer 12

Used for the dissection and/or the manipulation of objects.

Question 13

Stereobinocular microscope attributes? (5)

Answer 13

• Shows gross morphology of specimens.

• No treatment needed.

• Have a lower resolution/low magnification than that of a compound microscope.

• 2 light sources (above and below).

• See 3D images (whole specimen).

Question 14

Compound microscope?

Answer 14

= microscope where light is usually transmitted through the specimen.

Question 15

What is the Compound microscope used for?

Answer 15

Used to examine tissues and some cellular details.

Question 16

Compound microscope attributes? (4)

Answer 16

• 1 light source (below).

• See 2D images.

• Specimen is thinly sliced (treatment of specimen is often needed).

• When using it, never go to ×100 objective (only used for oil-immersed specimens).

Question 17

SEM?

Answer 17

= microscope where the electron beam scans the surface of the specimen.

Question 18

SEM attributes? (6)

Answer 18

• Allows for detailed examination of surface structures.

• Specimen must be treated.

• Produces SEM micrograph (greyscale).

• 3D images.

• Electron beam instead of light.

• Images are sometimes artificially coloured.

Question 19

TEM?

Answer 19

= microscope where electron beams are transmitted through the specimen.

Question 20

TEM attributes? (5)

Answer 20

• Examination of very small structures (eg, viruses, bacteria, internal cell structures, macromolecules).

• Very thinly sliced.

• TEM image: greyscale, ultrastructure of the cell.

• 2D images.

• Focuses on ultra structures.

Question 21

Egs of small structures that are examined under a TEM? (4)

Answer 21

• Viruses.
• Bacteria.
• Internal cell structures.
• Macromolecules.

Question 22

Units of measure used in Microscopy? (4)

Answer 22

• mm (millimetre).
• μm (micrometre).
• nm (nanometre).
• pm (picometre).

Question 23

mm =…?

Answer 23

1×10^(-3) m

Question 24

μm = …?

Answer 24

1×10^(-6) m

Question 25

nm = …?

Answer 25

1×10^(-9) m

Question 26

pm = …?

Answer 26

1×10^(-12) m

Question 27

Calculation of scale and size attributes? (5)

Answer 27

• Determine the actual size of the structures shown.

• Scale bar/magnification should be given with micrographs.

• Descriptive heading below micrograph.

• Describe micrograph/drawing properly.

• Add scale bar & magnification.

Question 28

Scale bar/magnification attributes? (3)

Answer 28

• Estimated, if only approximated size is required.
• Exact calculation can be acquired.
• Automatically done by camera/software.

Question 29

Micrograph heading pointers? (4)

Answer 29

• Type of section.
• Specimen/structure.
• What was it stained with.
• Under which magnification.