Microscopy

Question 1

What is a millimeter?

Answer 1

1 thousandth of a meter (1m / 1,000)
10-3meter
denoted by mm

Question 2

What is a micrometer?

Answer 2

1 millionth of a meter (1m / 1,000,000)
10-6meter
denoted by µm

Question 3

What is a nanometer?

Answer 3

1 billionth of a meter (1m / 1,000,000,000)
10-9meter
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 size are Bacteria?

Answer 9

Bacteria are about 1µm or smaller
1 millionth of a meter
10-6meter

Question 10

What size are viruses?

Answer 10

Viruses are about 1nm
1 billionth of a meter
10-9meter

Question 11

How many Viruses could fit into one Bacterium?

Answer 11

1,000 Viruses could fit into 1 Bacterium

Question 12

What are the two commonly used types of microscopes?

Answer 12

Simple and Compound

Question 13

How many lenses does each microscope have?

Answer 13

Simple has one (ocular)

Compound has one or more (ocular plus objective)

Question 14

Give an example of a compound microscope.

Answer 14

Brightfield

Question 15

What are the different types of compound microscopes?

Answer 15

Light microscope and Electron microscope

Question 16

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

Answer 16

Dissecting microscope

Question 17

When is a brightfield microscope used? x2

Answer 17

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

b. It can also be used for stained tissues.

Question 18

When is darkfield illumination needed?

Answer 18

a. It is used for live organisms with no stain.

b. It is also used to look at fluorescent organisms.

Question 19

What is the difference between brightfield and darkfield illumination?

Answer 19

Brightfield Illumination:

Darkfield Illumination:

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

19. 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? Are cells stained? How does the object and background appear?

Answer 27

Brightfield- Cells are either live and unstained or dead and stained. Dark objects are visible against a bright background.

Question 28

``` Phase-Contrast Are cells live or dead? Are cells stained? Are images three dimensional? What cell structures can be seen? ```

Answer 28

Cells are live No stain is used Not three-dimensional Can see cilia and flagella (signs of motility) more clearly than darkfield

Question 29

``` DIFFERENTIAL INTERFERENCE CONTRAST Are cells live or dead? Are cells stained? Are images three dimensional? What cell structures can be seen? How is resolution? ```

Answer 29

``` Cells are live No stain is used Shows three dimensions Can see cilia and flagella (signs of motility) more clearly than darkfield or phase contrast Best resolution for live cells ```

Question 30

FLUORESCENCE Are cells live or dead? Are cells stained? When is this used?

Answer 30

Cells are dead Stain is fluorescent dye- creates visible light Quick dx of TB & Syphilis

Question 31

``` TRANSMISSION ELECTRON Are cells live or dead? Are cells stained? Are images three dimensional? What cell structures can be seen? How is resolution? ```

Answer 31

``` Cells are dead Stain with heavy metal salts is used Images are not 3D Can see organelles in cells Best resolution of all microscopes ```

Question 32

SCANNING ELECTRON Are cells live or dead? Are images three dimensional? What structures can be seen?

Answer 32

Cells are dead Images are 3D Surface view only

Question 33

SCANNING PROBE Describe how it works What are 2 drawbacks?

Answer 33

Specimen is scanned, image is sent to computer-Drawback: Slower in acquiring images Drawback: Max image size is smaller

Question 34

``` Darkfiled Microscopy are cells live or dead are cells stained how does the object and background appear what cell structure can be seen ```

Answer 34

cells are live no stain light objects are visible against dark background can see cilia and flagella (signs of motility)