Robert Koch identified the cause of

Select one:

a. tuberculosis

.b. AIDS.

c. anthrax.

d. diphtheria.

e. smallpox.

c

The microbial process of converting sugars to alcohol is known as

Select one:

a. tyndallization

.b. fermentation.

c. lyophilization.

d. alcoholism.

e. pasteurization.

b

Biogenesis refers to the

Select one:

a. germ theory of disease.

b. spontaneous generation of organisms from nonliving matter.

c. development of life forms from preexisting life forms.

d. development of aseptic technique.

c

Microbes are associated with life-sustaining benefits as well as life-threatening diseases.

Select one:

True

False

T

The use of phenol (carbolic acid) as a wound disinfectant was first practiced by

Select one:

a. Semmelweis.

b. Lister.

c. Pasteur.

d. Holmes.

e. Koch.

B

The major food producers for other living organisms is/are

Select one:

a. higher plants.

b. cyanobacteria.

c. algae.

d. higher plants and algae.

e. higher plants, cyanobacteria, and algae

E

The first step for directly linking a microbe to a specific disease according to Koch's postulates is to

Select one:

a. compare the blood of a sick animal to blood obtained from a healthy animal.

b. inject a sample of blood or other body fluid from a diseased animal into a healthy animal.

c. isolate microbes from the blood of healthy animals.

d. obtain a sample of blood or other body fluid from a diseased animal.

e. culture the blood or other body fluid from a diseased animal using nutrient medium.

d

Commercial utilization of microbial products has become increasingly popular due to their environmentally friendly nature. Removal of these products from the environment typically utilizes

Select one:

a. organic acids

.b. enzymes.

c. organic solvents.

d. alcohol.

e. soap

b

A prokaryotic cell may possess each of the following cellular components EXCEPT

Select one

a. a cell wall.

b. flagella.

c. ribosomes.

d. a cell membrane.

e. a nucleus.

e

If you were setting up an experiment to disprove spontaneous generation in a liquid medium, which of the following would be essential to the experiment?

Select one:

a. adding antibiotics to the liquid

b. starting with a liquid that contains microorganisms

c. using a sterile liquid and eliminating exposure to microorganisms

d. supplying the liquid with nutrients

e. adding carbon dioxide to the liquid

c

Microorganisms are essential to our life. Each of the following is an example of a beneficial function of microorganisms EXCEPT

Select one:

a. agriculture.

b. gene therapy.

c. bioremediation.

d. alternative fuel production.

e. increased morbidity.

e

Archaea differ from bacteria in that archaea

Select one

:a. have diverse cell wall compositions.

b. are prokaryotic.

c. use organic compounds for food.

d. reproduce by binary fission.

e. lack nuclei.

a

Anton van Leeuwenhoek was the first microbiologist to use a microscope to examine environmental samples for the presence of microorganisms.

Select one:

True

False

t

The process of pasteurization to reduce food spoilage utilizes high heat to kill all bacteria present.

Select one:

True

False

f

All pathogens known to infect humans have been identified at this point in time.

Select one:

True

False

f

A student has obtained a sample of pond water for study. Using the high-power lens, he observes several cells with nuclei. He can conclude that the cells are NOT bacteria.

Select one:

True

False

t

Which of the following is NOT true regarding the acid-fast stain?

Select one:

a. It is used to identify members of the genus Mycobacterium.

b. Acid-fast cells appear red in a completed acid-fast stain.

c. If cells are acid-fast, they are gram-negative.

d. Acid-fast cells retain the primary dye after treatment with acid-alcohol.

e. Non-acid-fast microbes appear blue in a completed acid-fast stain.

c

A student is looking at a bacterial specimen using the oil immersion lens, but has forgotten to put immersion oil on the slide. The specimen will appear

Select one:

a. to have no color

.b. smaller than it would if immersion oil was used.

c. somewhat fuzzy and have poor resolution.

d. the same as it would if the immersion oil was used.

e. larger than it would if immersion oil was used.

c

Which of the following places the steps in the correct sequence?
1-Staining
2-Making a smear
3-Fixing

Select one:

a. 3-2-1

b. 2-3-1

c. 1-2-3

d. 1-3-2

e. The order is unimportant.

b

In a completed Gram stain, gram-positive bacteria are purple.

Select one:True False

t

Assume you stain Bacillus by applying malachite green with heat and then counterstaining with safranin. Through the microscope, the green structures are

Select one:

a. endospores.

b. cell walls

.c. flagella.

d. capsules

.e. The answer cannot be determined.

a

If acid-fast bacteria are stained with the Gram stain, they will stain gram-negative.

Select one:True False

F

Scanned probe microscopy is used to examine fine detail of molecular complexes, such as blood clots, or molecules, such as DNA.

Select one:True False

T

Which microscope takes advantage of differences in the refractive indexes of cell structures?

Select one:

a. electron microscope

b. phase-contrast microscope

c. compound light microscope

d. darkfield microscope

e. fluorescence microscope

B

Which microscope is best used for observing the surfaces of intact cells and viruses?

Select one:

a. brightfield microscope

b. scanning electron microscope

c. darkfield microscope

d. fluorescence microscope

e. phase-contrast microscope

B

You are performing a Gram stain on gram-negative bacteria and you stop after the decolorizer step. What is the appearance of the bacteria at this point?

Select one:

a. colorless

b. brown

c. purple

d. red

A

Both phase-contrast microscopy and differential interference contrast microscopy are used to
view the internal structures of cells without staining.

Select one:True False

T

The purpose of the ocular lens is to

Select one:

a. decrease the refractive index.

b. magnify the image from the objective lens.

c. decrease the light.

d. increase the light.

e. improve resolution.

B

Which microscope achieves the highest magnification and greatest resolution?

Select one:a. compound light microscope

b. darkfield microscope

c. fluorescence microscope

d. phase-contrast microscope

e. electron microscope

E

Simple staining is often necessary to improve contrast in which microscope?

Select one:

a. compound light microscope

b. darkfield microscope

c. fluorescence microscope

d. phase-contrast microscope Incorrect

e. electron microscope

A

You are performing a Gram stain on gram-negative bacteria and you stop after the addition of the mordant. What is the appearance of the bacteria at this point?

Select one

:a. purple

b. brown

c. colorless

d. red

A

Which microscope is used to see intracellular detail in a living cell?

Select one:

a. two-photon microscope

b. transmission electron microscope

c. brightfield microscope

d. atomic force microscope

e. fluorescence microscope

A

Cells viewed in darkfield microscopy appear similar to those stained with the negative stain.

Select one:True False

T

In using this microscope, the observer does NOT look directly at an image through a lens.

Select one:

a. fluorescence microscope

b. electron microscope

c. compound light microscope

d. phase-contrast microscope

e. darkfield microscope

B

You find colorless areas in cells in a gram-stained smear. What should you apply next?

Select one:

a. a flagella stain

b. a simple stain

c. an acid-fast stain

d. an endospore stain

e. a capsule stain

D

Which microscope is most useful for visualizing a biofilm?

Select one:

a. transmission electron microscope

b. phase-contrast microscope

c. scanning acoustic microscope

d. fluorescence microscope

e. compound light microscope

C

A gram-positive bacteria suddenly acquires resistance to the antibiotic methicillin. This trait most likely occurred due to

Select one:

a. meisosis

.b. transduction.

c. transformation.

d. binary fission.

e. conjugation

E

Which of the following structures is NOT found in some prokaryotic cells?
Select one:
a. cilium
b. flagellum
c. peritrichous flagella
d. pilus
e. axial filament

A

Which of the following are NOT energy reserves?
Select one:
a. sulfur granules
b. polysaccharide granules
c. carboxysomes
d. lipid inclusions
e. metachromatic granules

C

Which of the following statements is INCORRECT regarding prokaryotic cells?
Select one:
a. They typically have a circular chromosome.
b. Their DNA is not enclosed within a membrane.
c. They reproduce by binary fission.
d. They lack a plasma membrane.
e. They lack membrane-enclosed organelles.

D

Which of the following is NOT part of the passive transport process?
Select one:
a. concentration gradient
b. plasma membrane
c. ATP
d. aquaporins
e. transporter proteins

C

Endospores are a reproductive structure.
Select one:
True
False

F

How do spirochetes and spirilla differ?
Select one:
a. Spirilla have an external flagella but spirochetes have axial filaments.
b. Spirochetes have a rigid, corkscrew shape while spirilla are helical and more flexible.
c. Spirilla are found in chains of cells whereas spirochetes exist as individual cells.
d. Spirochetes and spirilla are basically the same organisms and the terms can be used interchangeably.
e. Spirochetes do not have a cell wall but spirilla do.

A

Which of the following statements about gram-negative cell walls is FALSE?
Select one:
a. They are toxic to humans.
b. They protect the cell in a hypotonic environment.
c. Their Gram reaction is due to the outer membrane.
d. They have an extra outer layer composed of lipoproteins, lipopolysaccharides, and phospholipids.
e. They are sensitive to penicillin.

E

Spheroplasts, protoplasts, and mycoplasms are bacterial cells without cell walls.
Select one:
True
False

T

Bacteria are a commonly used organism for studies of genetic material in the research laboratory. The nucleic acids must first be isolated from the cells for these studies. Which of the following would most likely be used to lyse the bacterial cells for nucleic acid isolation?
Select one:
a. polymixins
b. mycolic acid
c. water
d. lysozyme
e. alcohol

D

Where are phospholipids most likely found in a prokaryotic cell?
Select one:
a. flagella
b. around organelles
c. the plasma membrane
d. ribosomes
e. the plasma membrane and around organelles

C

In bacteria, photosynthetic pigments are found in
Select one:
a. chloroplasts.
b. ribosomes.
c. cytoplasm.
d. chromatophores.
e. mesosomes.

D

Antibiotics that target cell wall synthesis ultimately cause bacterial cell death as a result of
Select one:
a. cell shrinkage.
b. osmotic lysis.
c. decreased synthesis of peptidoglycan.
d. inhibition of molecular transport.
e. plasmolysis.

B

Which of the following is NOT found in mitochondria and prokaryotes?
Select one:
a. ATP-generating mechanism
b. 70S ribosomes
c. circular chromosome
d. binary fission
e. cell wall

E

Small, hydrophobic molecules pass through a cell membrane most easily by diffusion.

Select one:True False

T

Which of the following statements best describes what happens when a bacterial cell is placed in a solution containing 5 percent NaCl?
Select one:
a. The cell will undergo osmotic lysis.
b. Water will move out of the cell.
c. Sucrose will move into the cell from a higher to a lower concentration.
d. Water will move into the cell.
e. No change will result; the solution is isotonic.

B

Which of the following have a cell wall?
Select one:
a. fungi
b. animal cells
c. L forms
d. mycoplasmas
e. protoplasts

A

Which structure acts like an "invisibility cloak" and protects bacteria from being phagocytized?
Select one:
a. slime layer
b. cell membrane
c. fimbriae
d. capsule
e. cell wall

D

The cell walls of bacteria are responsible for the shape of the bacteria and the difference in the Gram stain reaction.

Select one:True False

T

Functions of the glycocalyx include all of the following EXCEPT
Select one:
a. binary fission.
b. biofilm formation.
c. increased virulence.
d. protection against dehydration.
e. source of nutrition.

A

Which of the following elements is NOT correctly matched with its cellular function?
Select one:
a. nitrogen - needed for amino acid synthesis
b. sulfur - used for synthesis of thiamin and biotin
c. phosphorus - incorporated into nucleic acids
d. magnesium and potassium - required as cofactors for enzymes
e. None of the answers is correct; all of the elements are correctly matched

E

Pathogenic bacteria isolated from the respiratory or intestinal tracts of humans are
Select one:
a. strict aerobes that grow best in reducing media.
b. facultative anaerobes that require reducing media for growth.
c. capnophiles that prefer highly oxygenated growth conditions.
d. capnophiles that grow best in carbon dioxide incubators.
e. strict aerobes that grow best in candle jars.

D

Assume you inoculated 100 cells into 100 ml of nutrient broth. You then inoculated 100 cells of the same species into 200 ml of nutrient broth. After incubation for 24 hours, you should have
Select one:
a. the same number of cells in both.
b. more cells in the 100 ml.
c. more cells in the 200 ml.
d. The answer cannot be determined based on the information provided.

A

A culture medium on which only gram-positive organisms grow and a yellow halo surrounds Staphylococcus aureus colonies is called aNo
Select one:
a. selective medium.
b. enrichment culture.
c. differential medium.
d. selective and differential medium.
e. differential and enrichment culture.

D

Thirty-six colonies grew in nutrient agar from 1.0 ml of undiluted sample in a standard plate count. How many cells were in the original sample?
Select one:
a. 4
b. 9
c. 18
d. 36
e. 72

D

Which organism is NOT correctly matched to its energy source?
Select one:
a. chemoautotroph - Fe2+
b. chemoautotroph-NH3
c. chemoheterotroph - glucose
d. photoautotroph - CO2
e. photoheterotroph - light

D

Which enzyme catalyzes the reaction: 2H2O2 → 2H2O + O2?
Select one:
a. oxidase
b. peroxidase
c. catalase
d. superoxide dismutase

C

Which group of microorganisms is most likely to spoil a freshwater trout preserved with salt?
Select one:
a. hyperthermophiles
b. psychrophiles
c. anaerobes
d. thermophiles
e. facultative halophiles

E

Most bacteria reproduce by
Select one:
a. binary fission.
b. budding.
c. aerial hyphae.
d. fragmentation.
e. mitosis.

A

During which growth phase will gram-positive bacteria be most susceptible to penicillin?
Select one:
a. log phase
b. death phase
c. lag phase
d. stationary phase
e. The culture is equally susceptible during all phases.

A

An isolated colony on a streak plate contains millions or billions of identical cells.
Select one:
True
False

T

Most fungi grow best at pH
Select one:
a. 1.
b. 5.
c. 7.
d. 9.
e. 14.

B

Which of the following uses glucose for carbon and energy?
Select one:
a. photoheterotroph
b. chemoheterotroph
c. chemoautotroph
d. photoautotroph

B

An experiment began with 4 cells and ended with 128 cells. How many generations did the
cells go through?
Select one:
a. 64
b. 32
c. 6
d. 5
e. 4

D

Which of the following has bacteriochlorophylls and uses alcohols for carbon?
Select one:
a. photoautotroph
b. chemoheterotroph
c. photoheterotroph
d. chemoautotroph

C

Which of the following pairs is mismatched?
Select one:
a. thermophile - growth at 37°C
b. psychrotroph - growth at 0°C
c. mesophile - growth at 25°C
d. hyperthermophiles - growth at 85°C
e. psychrophile - growth at 15°C

A

Cyanobacteria are a type of
Select one:
a. chemoautotroph.
b. photoheterotroph.
c. photoautotroph.
d. chemoheterotroph.

C

Which of the following uses CO2 for carbon and H2 for energy?
Select one:
a. chemoheterotroph
b. chemoautotroph
c. photoheterotroph
d. photoautotroph

B

Which of the following statements regarding metabolism is FALSE?
Select one:
a. Heat may be released in both anabolic and catabolic reactions.
b. ATP is formed in catabolic reactions.
c. Anabolic reactions are degradative.
d. ADP is formed in anabolic reactions.

C

Salts and sugars work to preserve foods by creating a
Select one:
a. hypotonic environment.
b. lower osmotic pressure.
c. depletion of nutrients.
d. hypertonic environment.
e. lower pH.

D