Microscopy

Question 1

What is a millimeter?

Answer 1

1 thousandth of a meter (1m / 1,000)
10 to the 3rd power meter
denoted by mm

Question 2

What is a micrometer?

Answer 2

1 millionth of a meter (1m / 1,000,000)
10 to the 6th power meter
denoted by µm

Question 3

What is a nanometer?

Answer 3

1 billionth of a meter (1m / 1,000,000,000)
10 to the 9th power meter
denoted by nm

Question 4

What is 1 meter equivalent to in millimeters?

Answer 4

1m = 1,000mm

Question 5

What is 1 meter equivalent to in micrometers?

Answer 5

1m = 1,000,000µm

Question 6

What is 1 meter equivalent to in nanometers?

Answer 6

1m = 1,000,000,000nm

Question 7

What is 1mm equivalent to in µm?

Answer 7

1mm = 1,000µm

Question 8

What is 1mm equivalent to in nm?

Answer 8

1mm = 1,000,000nm

Question 9

What is 1µm equivalent to in nm?

Answer 9

1µm = 1,000nm

Question 10

What size are Bacteria?

Answer 10

Bacteria are about 1µm or smaller
1 millionth of a meter
10 to the 6th power meter

Question 11

What size are viruses?

Answer 11

Viruses are about 1nm
1 billionth of a meter
10 to the 9th power meter

Question 12

How many Viruses could fit into one Bacterium?

Answer 12

1,000 Viruses could fit into 1 Bacterium

Question 13

What are the two commonly used types of microscopes?

Answer 13

Simple and Compound

Question 14

How many lenses does each microscope have?

Answer 14

Simple has one (ocular).

Compound has one or more (ocular plus objective).

Question 15

Give an example of a compound microscope.

Answer 15

Brightfield

Question 16

What are the different types of compound microscopes?

Answer 16

Light microscope and Electron microscope

Question 17

What type of microscope is used to look at large objects?

Answer 17

Dissecting microscope

Question 18

When is a brightfield microscope used?

Answer 18

• It is used for looking at live organisms with no stain.

- It can also be used for stained tissues.

Question 19

When is darkfield illumination needed?

Answer 19

• It is used for live organisms with no stain.

- It is also used to look at fluorescent organisms.

Question 20

What is Phase Contrast Microscopy used for?

Answer 20

Used for seeing organelles in live organisms, 2D.

Question 21

What is Differential Interference Contrast used for?

Answer 21

Used for seeing organelles in live organisms in three dimensions.

Question 22

Describe Fluorescence Microscopy.

Answer 22

Cells are stained with fluorescent dyes (called fluorochromes). UV Light is shined on the specimen. Fluorescent substances absorb UV light and emit visible light.

Question 23

What is difference between regular microscopes and Transmission Electron Microscopes?

Answer 23

Transmission Electron Microscopes have a much higher resolution than regular microscopes.

Question 24

Are cells live or dead with a Transmission Electron Microscope?

Answer 24

You can only view dead cells under the transmission electron microscope.

Question 25

What is the difference between a Scanning Electron Microscope and a transmission electron microscope?

Answer 25

Scanning Electron Microscope has a very high resolution like a transmission electron microscope except it makes images in three dimensions.

Question 26

What happens in a Scanning Probe Microscope and how does it affect the color?

Answer 26

Scanning Probe Microscope passes a scan over the specimen, line by line. The surface dimensions are recorded and sent to a computer, which shows the image in false color.

Question 27

Brightfield microscopy: Are cells live or dead?

Answer 27

Cells are either live and unstained or dead and stained.

Question 28

Brightfield microscopy: Are cells stained?

Answer 28

Stain is used.

Question 29

Brightfield microscopy: How does the object and background appear?

Answer 29

Dark objects are visible against a bright background.

Question 30

Darkfield microscopy: Are cells live or dead?

Answer 30

Live

Question 31

Darkfield microscopy: Are cells stained?

Answer 31

No stain is used.

Question 32

Darkfield microscopy: How does the object and background appear?

Answer 32

Light objects are visible against dark background.

Question 33

Darkfield microscopy: What cell structure can be seen?

Answer 33

Can see cilia and flagella (signs of motility).

Question 34

Phase-Contrast: Are cells live or dead?

Answer 34

Live

Question 35

Phase-Contrast: Are cells stained?

Answer 35

No stain is used.

Question 36

Phase-Contrast: Are images three-dimensional?

Answer 36

Not three-dimensional.

Question 37

Phase-Contrast: What cell structures can be seen?

Answer 37

Can see cilia and flagella (signs of motility) more clearly than darkfield.

Question 38

DIFFERENTIAL INTERFERENCE CONTRAST: Are cells live or dead?

Answer 38

Live

Question 39

DIFFERENTIAL INTERFERENCE CONTRAST: Are cells stained?

Answer 39

No stain is used.

Question 40

DIFFERENTIAL INTERFERENCE CONTRAST: Are images three-dimensional?

Answer 40

Shows three-dimensions.

Question 41

DIFFERENTIAL INTERFERENCE CONTRAST: What cell structures can be seen?

Answer 41

Can see cilia and flagella (signs of motility) more clearly than darkfield or phase contrast.

Question 42

DIFFERENTIAL INTERFERENCE CONTRAST: How is resolution?

Answer 42

Best resolution for live cells.

Question 43

FLUORESCENCE: Are cells live or dead?

Answer 43

Dead

Question 44

FLUORESCENCE: Are cells stained?

Answer 44

Stain is fluorescent dye- creates visible light

Question 45

FLUORESCENCE: When is this used?

Answer 45

Quick dx of TB & Syphilis

Question 46

TRANSMISSION ELECTRON: Are cells live or dead?

Answer 46

Dead

Question 47

TRANSMISSION ELECTRON: Are cells stained?

Answer 47

Stain with heavy metal salts is used.

Question 48

TRANSMISSION ELECTRON: Are images three-dimensional?

Answer 48

Images are not three-dimensional.

Question 49

TRANSMISSION ELECTRON: What cell structures can be seen?

Answer 49

Can see organelles in cells.

Question 50

TRANSMISSION ELECTRON: How is resolution?

Answer 50

Best resolution of all microscopes.

Question 51

SCANNING ELECTRON: Are cells live or dead?

Answer 51

Dead

Question 52

SCANNING ELECTRON: Are images three-dimensional?

Answer 52

Images are three-dimensional.

Question 53

SCANNING ELECTRON: What structures can be seen?

Answer 53

Surface view only.

Question 54

SCANNING PROBE: Describe how it works.

Answer 54

Specimen is scanned, image is sent to computer.

Question 55

SCANNING PROBE: What are 2 drawbacks?

Answer 55

Slower in acquiring images. | Max image size is smaller.