Exam 1 - Ch.4 - Microscopy, Staining, and Classification

Question 1

The shortest distance between two points on a specimen that can still be distinguished by the observer as separate entities.

Answer 1

Resolution

Question 2

Differences in intensity between two objects, or between an object and background.

Answer 2

Contrast

Question 3

What increases contrast?

Answer 3

staining

Question 4

What is important in determining resolution?

Answer 4

contrast

Question 5

What is staining?

Answer 5

Increasing contrast and resolution by coloring specimens with stains/dyes.

Question 6

What must happen to a smear of microorganisms (thin film) prior to staining?

Answer 6

Must be fixed with heat!

Question 7

What two types of stains are used for Gram staining?

Answer 7

Crystal violet and safranin

Question 8

What color does safranin stain?

Answer 8

Magenta/red

Question 9

What two stains are used for an acid-fast stain?

Answer 9

Carbon fuchsin and methylene blue

Question 10

Carbon fuchsin stains what color?

Answer 10

Bright fire-engine red

Question 11

What stains are used for an endospore stain?

Answer 11

Malachite green and safranin

Question 12

What are the three steps in Gram staining?

Answer 12

1) crystal violet stain
2) decolorize with alcohol
3) counterstain with safranin

Question 13

What happens during the decolorization step in Gram staining?

Answer 13

Purple is washed from the Gram (-) cells.

Question 14

Why does the alcohol was the color from the Gram (-) cells?

Answer 14

Because the walls are thinner.

Question 15

The safranin colors which cells in Gram staining?

Answer 15

Gram (-)

Question 16

The purple colors which cells in Gram staining?

Answer 16

Gram (+)

Question 17

What are mycobacteria?

Answer 17

A group of bacteria that do not have the typical peptidoglycan cell walls.

Question 18

Mycobacteria cell walls have high what?

Answer 18

Waxy mycolic acid content

Question 19

What makes Mycobacteria resistant to decolorization by acids during staining procedures?

Answer 19

They high waxy mycolic acid content.

Question 20

Mycobacteria of referred to as what?

Answer 20

Acid-fast bacteria

Question 21

What are the 3 steps in acid-fast staining?

Answer 21

1) carbon fuchsin primary stain
2) decolorixze (alcohol)
3) counterstain with methylene blue

Question 22

What happens when you decolorize during step two of acid fast staining?

Answer 22

Acid-fast cells retain their red color because the acid cannot penetrate the waxy wall.

Question 23

Mycobacteria stain what color?

Answer 23

Bright red

Question 24

Red are what types of cells

Answer 24

Acid-fast cells/mycobacteria

Question 25

What stains blue?

Answer 25

Non-acid fast cells like human cells and tissue. (any cell NOT Mycobacteria).

Question 26

What are the three steps in endospore staining?

Answer 26

1) malachite green primary stain 2) decolorize with water 3) counterstain with safranin

Question 27

What is important in the first step of endospore staining with malachite green?

Answer 27

Use heat to drive into endospore.

Question 28

What color do the endospores color?

Answer 28

Green

Question 29

What color do non-endospores color?

Answer 29

Magenta/red vegetative cells (non-endospore)

Question 30

Gram (+) bacteria genus names usually end in what?

Answer 30

-um and -us

Question 31

What are the exceptions to Gram (+) genus names (ending in -um and -us)?

Answer 31

Listeria Nocardia Actinomyces Steptomyces

Question 32

Listeria bacteria causes what?

Answer 32

Food poisoning

Question 33

Nocardia causes what?

Answer 33

lung abscesses

Question 34

Actinomyces causes what?

Answer 34

Oral abscesses

Question 35

Streptomyces is important in what?

Answer 35

Important source of antibiotics

Question 36

Gram (-) bacteria genus names usually end in what?

Answer 36

-a and -er

Question 37

What are the exception to a Gram (-) ending in -a or -er?

Answer 37

Pseudomonas Proteus vibrio haemophilus

Question 38

What does the bacteria pseudomonas cause?

Answer 38

Pneumonia, burn infections

Question 39

What does Proteus cause?

Answer 39

UTIs

Question 40

What does vibrio cause?

Answer 40

cholera

Question 41

What does haemophilus cause?

Answer 41

Meningitis in children

Question 42

What are some types of Mycobacteria?

Answer 42

Tuberculosis Leprosy buruli ulcer

Question 43

What is an acid-fast bacteria?

Answer 43

mycobacteria

Question 44

What will a bacteria with no cell wall stain in Gram staining?

Answer 44

It will stain red in Gram-stain

Question 45

When a bacteria with no cell wall is grown on media what does it look like?

Answer 45

Forms distinctive "fried egg" appearance

Question 46

Bacteria with no cell wall must colonize in what types of habitats?

Answer 46

In osmotically protected habitats such as animal or human bodies.

Question 47

Give an example of a bacteria with no cell wall?

Answer 47

mycoplasma

Question 48

What does mycoplasma cause?

Answer 48

pneumonia

Question 49

What is the classification and identification of microorganisms called?

Answer 49

taxonomy

Question 50

What is Linnaeus?

Answer 50

System classifying organisms based on characteristics in common.

Question 51

What type of nomenclature is used?

Answer 51

Binomial nomenclature

Question 52

What does binomial nomenclature look like?

Answer 52

Genus species (in italics, first part capitalized)

Question 53

Who compared nucleotide sequences of rRNA subunits in classifying bacteria?

Answer 53

Carl Woese

Question 54

What 3 domains did Carl Wiese propose as determined by rRNA sequences?

Answer 54

eukarya Bacteria archaea

Question 55

Bacteria and archaea are what types of cells?

Answer 55

prokaryote

Question 56

What are the five types of eukarya?

Answer 56

``` Animals Plants Fungi Protozoan algae ```

Question 57

What is acellular?

Answer 57

Viruses

Question 58

What are helminths technically labeled?

Answer 58

Eukaryotes - animal | helminths are worms

Question 59

What is a type of taxonomic key?

Answer 59

Dichotomous keys

Question 60

What are dichotomous keys?

Answer 60

A series of paired statements where only one of two "either/or" choices applies to any particular organism.

Question 61

How do the dichotomous keys work?

Answer 61

Key directs user to another pair of statements, or provides name of organism.

Question 62

What is the end point of a dichotomous key called?

Answer 62

Terminal key