Chapter 3 Flashcards Preview

GSU Microbiology > Chapter 3 > Flashcards

Flashcards in Chapter 3 Deck (28):
1

Microorganisms are measured in micrometers (μm) and .....

nanometers (nm)

2

A simple microscope has how many lenses?

One

3

What is a light microscope?

Any kind of microscope that uses visible light to observe specimens

4

The ability of microscope lenses to distinguish two points is known as...

Resolution

5

Which light wavelength provides greater resolution, long or short?

Short

6

The measure of the
light-bending ability of a medium is known as....

The Refractive Index

7

What type of microscopy
1) Allows examination of living organisms and internal cell structures
AND
2)Brings together two sets of light rays, direct rays, and diffracted rays to form an image?

Phase-Contrast microscopes

8

What type of microscopy uses UV (short wavelength) light?

Fluorescence Microscopy

9

In which type of microscopy are cells stained with fluorochrome dyes?

Confocal Microscopy

10

In which type of microscopy are two photons of long-wavelength (red) light used to excite the dyes?

Two-Photon Microscopy

11

Which type of microscopy measures sound waves that are reflected back from a specimen?

Scanning Acoustic Microscopy

12

Which type of microscopy
1)Uses electrons instead of light
AND
2)Is used for images too small to be seen with light microscopes, such as viruses?

Electron Microscopy

13

In which type of microscopy
1)Is a beam of electrons passed through ultra-thin sections of a specimen, then through an electromagnetic lens, then focused on a projector lens
AND
2)Are specimens sometimes stained with heavy-metal salts for contrast?

Transmission Electron Microscopy

14

Which type of microscopy
1)Uses a tungsten probe to scan a specimen and reveal details of its surface
AND
2)Has a resolution of 1/100 of an atom?

Scanning Tunneling Microscopy

15

Which type of microscopy
1)Uses a metal-and-diamond probe placed onto a specimen
AND
2)Produces three-dimensional images?

Atomic Force Microscopy

16

Staining the background instead of the cell is called?

Negative staining

17

What is a mordant's function in staining?

It holds the stain or coats the specimen to enlarge it

18

Differential Stains are used to distinguish between Gram and ______ Stain

Acid-Fast

19

Gram-positive bacteria have _____ peptidoglycan cell walls

Thick

20

Gram-negative bacteria have _____ peptidoglycan cell walls AND a layer of lipopolysaccharides

Thin

21

Acid-Fast staining only works on bacteria ___________

Not decolorized by acid-alcohol

22

What is the function of iodine in the staining process?

Mordant

23

What is the function of safranin in the staining process?

Counter-Stain

24

If the cells retain the Crystal violet dye after the alcohol wash (decolorization) they are....

Gram-Positive

25

Capsules are a gelatinous covering that ____ accept most dyes

Don't

26

Endospores are resistant, dormant structures inside some cells that _____ be stained by ordinary methods

Cannot

27

What primary stain dye works on endospores?

Malachite green
(Usually with heat)

28

True or False?
Water can decolorize endospiric cells

True