Exam 1 Mehari exams compilation

Who was the nurse who realized soldiers were dying from malnutrition, poor sanitation and lack of activity and created polar area diagrams to use as evidence towards the necessity of better patient welfare in hospitals?

Florence Nightingale

The relationship between specific bacteria and specific diseases was first demonstrated by Pasteur.

false

The ribosomal RNA studies that led to the division of prokaryotic organisms into the Bacteria and the archaea were begun by

Carl Woese

A new microbe has been discovered in the rumen of sheep. Microscopy shows no evidence of a nuclear membrane and biochemical studies of the cell wall demonstrate the lack of peptidozlycan. Metabolic studies show that this microbe generates methane. This microbe would most likely be classified in

domain Archea

Which of the following individuals, was the first to observe and accurately describe single-celled microorganisms?

Van Leeuwenhoek

Louis Pasteur is a French microbiologist who is credited for his MANY contributions to the held of microbiology. Which of the following is NOT an accomplishment of Louis Pasteur?

he identified the cause of anthrax as a bacterium (That was Robert Koch

Although developed over 100 years ago. Koch's postulates continue to be used successfully in all known human infectious diseases.

false

What would the results of Pastel's swan-neck flask experiment looked like if it supported the theory of spontaneous generation?

Chemicals in the broth came together to form living organisms

What is the correct order of Koch's postulate?

C-A-D-B

Robert Koch is a German physician known for his contribution to medical microbiology. When he proposed his four postulates, Robert Koch considered which of the following factors?

infectious bacteria

All of the following are arguments that support the classification of archaea as a third domain of life apart from Bacteria, EXCEPT?

microscopic characteristics of archea are different from bacteria

Koch's postulates would work to identify the following organisms as a cause of disease EXCEPT?

Influenza Virus (His worked for bacteria)

Cells with a relatively simple cell morphology that do not have a true membrane-delimited nucleus are called

prokaryotes

The endosymblotiotic hypothesis is generally accepted as the origin of many eukaryotic organelles

True

antiseptic surgery was pioneered by?

Lister

Which of the following provides the best explanation for why viruses are not included in the three domain system?

Viruses are not cellular life form

You have isolated a bacterium that you believe to be the causative agent of a new disease in mice. How would you test the second Koch's postulates?

isolate the bacterium and grow a pure culture outside the mouse

For Pasteur's swan-necked flask experiment to work, all of the following are required EXCEPT?

chemicals in the broth muct be removed before they change into living organisms

A student is observing microorganisms in a sample of pond water. One organism of interest has an obvious nucleus, small oval structures containing a green pigment, and does not appear to be motile. in which of the following groups would this microbe most likely be classified?

Eukaryotes (Algae)

Who of the following developed a set of criteria that could be used to establish a causative link between a particular microorganism and a particular disease?

Koch

Resolution improves when the wavelength of the illuminating light decreases.

true

The instrument that produces a bright image of the specimen against a dark background is called a/an microscope.

dark field

the gram staining procedure is an example of

differential staining

A simple way to observe microbes is to place them in a drop of water on a slide with a coverslip. This technique is called____ preparation

wet mount

Which of these numeric aperture and wavelength combinations would give the best resolution?

Numeric aperture= 0.8 wavelength =400nm

Il the objective lenses of a microscope can be changed without losing focus on the specimen, they are said to be___

parfocal

A scanning microscope can resolve images as small as 10nm this is equivalent to

0.01 um

Your research group is performing research on aquatic microbial life in a local pond. Your assignment is to take images of live microorganisms showing their organelles. Which type of microscope would you use to achieve this?

Phase-contrast microscope

Light rays are refracted (bent) when they cross the interface between materials with different refractive indices

true

In the Gram-staining procedure the primary stain is

crystal violet

Prior to staining, smears of microorganisms are heat-fixed in order to

attach them firmly to the side

Mimivirus has a size of 390 rm in length, and 220 am in diameter. Can this virus be resolved with a compound light (bright field) microscope?

True

After the decolorizer has been added, Gram-positive organisms are stained_____ and Gram-negative organisms are stained_____

purple, colorless

small internal cell structures that are measured in nanometers are best visualized using a

Transmission electron microscope (TEM)

which of these series arranges microbes from smallest to largest?

ebola virus -> E coli-> Red blood cell ->Thiomargarita namibiensis

If you wish to use an immunofluorescence stain to differentiate between E. coli and Staphylococcus aureus, which of the following components of the fluorescent microscopy technique would be DIFFERENT between the two sample preparations so that you will be able to differentiate one organism from the other?

antibodies

What is the index of refraction for a vacuum?

1

What is the index of refraction for air?

1.000277

What is the index of refraction for water?

1.333333

What is the index of refraction for ice?

1.31

What is the index of refraction for glass/oil?

about 1.5

What is the index of refraction for a diamond?

2.417

Numerical aperture is 15 degrees and the medium is air

0.26

Numerical aperture is 20 degrees and the medium is air

0.34

Numerical aperture is 30 degrees and the medium is air

0.5

Numerical aperture is 60 degrees and the medium is air

0.87

Which arrangement is commonly seen in the genus Staphylococcus?

Clusters

You study a bacterium that grows in very low aqueous environments. Which type of transport mechanism is required to deliver nutrients from these environments where they are at a lower concentration than inside the cell?

active transport (Low to high)

all of the following are reasons we perform gram staining except

to determine tuberculosis infection

3 multiple choice options

which of the following is FALSE about the bacterial outer membrane

it is composed of a phospholipid bilayer

3 multiple choice options

what is one difference between acid fast and gram stain?

acid fast is used to stain mycobacterium species

3 multiple choice options

The lipid membrane of archea posses what type of bond linking them

ether

which of the following is a unique of an archael cell membrane living in a hot spring?

Ether linked fatty acids

T/F- Some bacteria have multiple flagella randomly distributed around their surface

true

coupling of transcription and translation is possible in which of the following domain/s?

Archaea and bacteria

Invisible living creatures were thought to exist and cause disease long before they were ever observed

True

Which of the following individuals is credited for definitively disproving the theory of spontaneous generation using broth in swan-neck flask?

Louis Pasteur

in the gram staining procedure he decolorizer is

ethanol or acetone

if you forgot to apply the sanfranin stain while performing a gram stain what outcome would you expect

Gram-negative bacteria would be colorless

in the Gram staining procedure the counter stain is...

sanfranin

Immersion oil can be used to increase the resolution achieved with some microscope lenses because it increases the_______between the specimen and the objective lens.

refractive index

in the gram staining procedure the mordant is

Iodine

If the decolorizer is NOT left on the specimen long enough in the Gram-staining procedure, Gram-positive organisms will be stained ........ and Gram-negative organisms will be stained.....

purple and purple

what are the two commonalities between gram negative and gram positive cell envelopes?

peptidoglycan and cell membrane

which of the following antibiotics target the peptidoglycan cell wall of bacteria

Both Penicillin and Vancomycin

2 multiple choice options

T/F all bacteria have at least one flagellum

false

Who is credited with developing and documenting the first vaccination against smallpox?

jenner

Louis Pasteur is a French microbiologist who is credited for his

MANY contributions to the field of microbiology. Which of the following is NOT an accomplishment of Louis Pasteur?

he identified the cause of anthrax as a bacterium

2 multiple choice options

Gram staining is a technique used to divide bacterial species into two groups based on differences in their DNA composition

false

A microscope that exposes specimens to ultraviolet, violet, or blue light and forms an image with the light emitted at a different wavelength is called a_____

microscope.

florescence microscope

after the decolorizer has been added, gram positive organisms are stained___ and gram negative organisms are stained

purple and colorless

which of these numeric aperture and wave length combinations would give the best resolution

NA= 0.8, wavelength = 400 nm

3 multiple choice options

Immersion oil can be used to increase the resolution achieved with same microscope lenses because it increases the between the specimen and the objective lens.

refractive index

what is TRUE regarding proteins that are embedded within the cell membrane

they act as transporter proteins

2 multiple choice options

A student in the lab performs a Gram stain on Staphylococcus aureus, a Gram positive cocci. The student skips the decolorizing step. When the student obserjes the slide under 100x magnification what does he or she see?

gram positive cocci

2 multiple choice options