Microbiology Chp. 4 And Lab Exam 1, Exercises 1-7

Front 1

____________ refers to the passage of light or electrons of various ___________ through lesnses to magnify objects and provide resolution and contranst so that those objects can be viewed and studied.

Back 1

Microscopy

wavelengths

Front 2

_________ ___ is used in light microscopy to fill the space between the specimen and a lens to reduce light refraction and thurs increase the ____________ _________ and resolution.

Back 2

Immersion oil

numerical aperature

Front 3

Staining techniques and polarized light may be used to enhance __________ between an object and its background.

Back 3

contrast

Front 4

_______ ________ contain a single magnifying lens, whereas ________ _______ use a series of lenses for magnification.

Back 4

simple microscopes

compound microscopes

Front 5

The lens closes to the object being magnified is the _______ ______, several of which are mounted on a ________ __________. the lenses colsest to the eyes are ________ _______. ________ _______ lie beneath the stage and direct light throught the slide.

Back 5

objective lens

revolving nosepiece

ocular lenses

condenser lenses

Front 6

The magnification of the objective lens and the ocular lens are multiplied together to give _________ _________.

Back 6

total magnification

Front 7

a photograph of a microscopic image is a _____________.

Back 7

Micropgraph

Front 8

____________ ____________ provide a dark background for small or colorless specimens.

Back 8

dark-field microscopes

Front 9

_______ ____________, such as _______ ____________ and differential interference contrast (Nomarsk) microscopes, cause light rays that pass through a specimen to be out of phase with light rays that pass through the field, producing __________.

Back 9

phase microscopes

phase contrast

contrast

Front 10

___________ ____________ use ultraviolet light and fluorescent dyes to fluoresce specimens and enhance __________.

Back 10

Fluorescence microscopes

contrast

Front 11

A ____________ ____________ uses fluorescent dyes in conjunction with computers to provide three dimensional images of a specimen.

Back 11

confocal microscope

Front 12

A _______________ ____________ ______________ provides an image produced by the transmission of electrouns through a thinly sliced dehydrated specimen.

Back 12

transmission electron microscope

Front 13

A ______________ ____________ ___________ provides a three dimensional image by scattering electrouns from the metal coated surface of a specimen.

Back 13

scanning electron microscope

Front 14

Minuscule electrounic probes are used in ____________ _____________ _____________ and in ________ _______ _____________ to reveal details at the atomic level.

Back 14

scanning tunneling microscopes

atomic force microscopes

Front 15

Preparing to ________ organisms with dyes for light microscopy involves making a _______, or thin film, of the specimens on a slide and then either passing the slide through a flame (_____ _________) or applying a (__________ __________) to attach the specimens to the slide. ______ dyes or _______ dyes are used to stain different portions of an organism to aid viewing and identification.

Back 15

stain

smear

heat fixation

chemical fixation

acidic

basic

Front 16

__________ ________ involve the simple process of soaking the smear with one dye and then rinsing with water. ___________ ________ such as the _________ ________, ___________ _______, endospore stain, Gomori methenamin silver (GMS) stain, and the homtoxylin and eosin (HE) stain use more than one dye to differentiate different cells, chemicals, or structures.

Back 16

Simple stains

Differential stains

gram stain

acidfast stain

Front 17

Gram-positive= Pink or Purple

Back 17

purple

Front 18

Gram-negative= Pink or Purple

Back 18

pink

Front 19

The Gram stain procedure includes use of a ________ _______, a __________, a ______________ _______, and a _______________ which results in either a pink or purple depending on there cell walls.

Back 19

primary stain

mordant

decolorizing

counterstain

Front 20

The ______________ stain is used to differentiate cells with waxy cell walls. ____________ are stained by the Schaeffer-Fulton __________ stain procedure.

Back 20

acid-fast

endospores

endospore

Front 21

Dyes that stain the background and leave the cell colorless are called _________ (or ________ ________)

Back 21

negative

capsule stains

Front 22

______ are nonoverlapping groups of organisms that are studied and named in ____________. Carolus Linnaeus invented a system of ___________.

Back 22

Taxa

taxonomy

taxonomy

Front 23

order of taxonomy......

Back 23

kingdom

phylum

class

order

family

genus

species

Front 24

Linnaeus gave each species a descriptive name consisting of a _________ name and _________ _________. This practice of naming organisms with two names is call ___________ ______________.

Back 24

genus
specific epithet

binomial nomenclature

Front 25

Carl Woese proposed the existence of three taxonomic _________ based on three cell types recealed by rRNA sequencing: _________, _________, and __________.

Back 25

domains

Eukarya

Bacteria

Archaea

Front 26

Taxonomists rely primarily on genetic differences revealed by morphological and metabolic dissimilarities to classify organisms. Species or strains withing species may be distinguished by using ________; ___________ test; nucleic acid analysis, particularly G+C content; or ______ ________ with bacteriophages, in wich unknown bacteria are identified by observing ________ (regions of a bacterial lawn where the phage has killed bacterial cells).

Back 26

antisera; agglutination tests

phage typing

plaques

Front 27

microbiologist use _______________ ______, which involve stepwise choices between paired characteristics, to help them identify microbes.

Back 27

dichotomous keys

Front 28

A nanometer is ______________ than a micrometer.

a. 10 times larger

b. 10 times smaller

c. 1000 times larger

d. 1000 times smaller

Front 29

Resolution is best described as....

Front 30

Curved glass lenses ___________ light.

Front 31

What factors are important in making an image appear larger?

a. the thickness of the lens

b. the curvature of the lens

c. the speed of the light passing through the lens

d. all of the above.

Front 32

Which of the following is different between light microscopy and transmission electron microscopy?

a. magnification

b. resolution

c. wavelengths

d. all of the above

Front 33

Which of the following types of microscopes produces a three dimensional image with a shadowed appearance?

a. simple microscope

b. differential interference contrast microscope

c. fluorescent microscope

d. transmission electron microscope

Front 34

Which of the following microscopes combines the greatest magnification with the best resolution?

a. confocal microscope

b. phase contrast microscope

c. dark field microscope

d. bright field microscope

Front 35

negative stains such as eosin are also called__________ ________.

a. capsule stains

b. endospore stains

c. simple stains

d. acid fast stains

Back 35

capsule stains

Front 36

In the binomial system of nomenclature, which term is always written in lowercase letters.

a. kingdom

b. domain

c. genus

d. specific epithet

Front 37

If an objective magnifies 40X and each binocular lens magnifies 15X, the total magnification of the object being viewed is ____________.

Front 38

The type of fixation developed by Koch for bacteria is ____________.

Front 39

Immersion oil _________ (increases/decreases) the numerical aperture,

which __________ (increases/decreases) resolution because __________ (more/fewer) light rays are involved.

Front 40

______________ refers to differences in intensity between two objects.

Back 40

resolution

Front 41

Cationic chromophores such as methylene blue ionically bond to ____________ (positively/negatively) charged chemicals such as DNA and proteins.

Front 42

parts of the microscope

Front 43

Gram Stain differentiates bacteria into 2 groups.

Gram+

Gram+ will stain ___________

Gram+ cell wall has....

Gram-

Gram- will stain ____________

Gram- cell wall has......

Back 43

purple

thick peptidoglycan layer

pink

thin peptidoglycan & outer membrane

Front 44

Gram Stain includes 4 steps?

1.) crystal Violet- which is the -_____________

2.) ______________- which is the -Mordant

3.) ______________- which is the -_____________

4.) ______________- which is the -Counterstain

Back 44

1.) primary stain

2.) iodine

3.) ethanol or acetone =decolorizer

4.) safranin

Front 45

Gram- cells have thin cell walls which allows the __________ and __________ to be washed away with acetone or ethanol. Afterward these cells are __________.

Back 45

(primary stain - crystal violet)

&

(mordant - iodine)

clear

Front 46

explain how the principle "electrons travel as waves" applies to microscopy.

Front 47

critique the following definition of magnification given by a student on a microbiology test: "magnification makes things bigger."

Back 47

magnification is the apparent increase in size of an object.

Front 48

Why can electron microscopes magnify only dead organisms?

Front 49

put the following substances in the order they are used in a Gram stain: Counterstain, decolorizing agent, mordant, primary stain.

Front 50

why is latin used in taxanomic nomenclature?

Front 51

Give three characteristics of "specific epithet."

Front 52

how does the study of the nucleotide sequences of ribosomal RNA fit into a discussion of taxonomy?

Front 53

An atomic force microscope can magnify a living cell, whereas electron microscopes and scanning tunneling microscopes cannot. what requirement of electron and scanning tunneling microscopes preclude the imaging of living specimens?

Front 54

Why is the definition of species as "successfully interbreeding organisms" not satisfactory for most microorganisms?

Front 55

What is the function of immersion oil

Back 55

Immersion oil concentrates the light source through to the objective.

without immersion oil light is refracted as it moves from the cover glass into the air and misses the objective lense.

Front 56

identify the two primary metric units used to measure the diameters of microbes

Back 56

micrometer (um) = diameter of cell measurments

nanometer (nm) = used to measure organelles in microbes and viruses

Front 57

list the metric units of length in order, from meter to nanometer.

Back 57

meter

decimeter

centimeter

millimeter

micrometer

nanometer

Front 58

curved glass lenses refract _______, and magnetic fields refract ___________ beams.

Back 58

light

electron

Front 59

an image magnified millions of times using a combination of lenses but the image still appears faint and blurry

Back 59

empty magnification

Front 60

the clarity of an image is determined by the __________ & __________.

Back 60

resolution and contrast

Front 61

numerical aperature refers to....

Back 61

the ability of a lens to gather light.

i.e. when immersion oil is used the numerical aperature increases.

Front 62

resolution distance depends on what two things?

Back 62

Wavelength

and

Numerical aperature

Front 63

staining increases __________. Using light that is in phase increases __________.

Back 63

contrast

contrast

Front 64

four kinds of light microscopy and there uses:

bright field = bacteria and nucleus

dark field = endospores

normarski = life unstainable samples