Deck 2: Characteristics of Microorganisms

Question 1

Bacilli are shaped like:

A)spheres.
B)cylinders or rods.
C)curved or spiral forms.
D)flat disks.

Answer 1

cylinders or rods.

Question 2

Regular bacteria, excluding Rickettsia and Chlamydia, multiply:

A)in the absence of nutrients.
B)only when they are inside of living cells.
C)when they are outside of living cells.
D)only when the temperature is below 7°

Answer 2

when they are outside of living cells.

Question 3

Those bacteria that die in the presence of oxygen are called:

A)aerobes.
B)mesophiles.
C)acidogens.
D)anaerobes.

Answer 3

anaerobes.

Question 4

Which of the following bacterial structures controls the flow of nutrients and waste into and out of the cell?

A)Cell wall
B)Flagellum
C)Cytoplasmic membrane
D)Capsule

Question 5

Cocci are shaped like:

A)spheres.
B)cylinders or rods.
C)curved or spiral forms.
D)flat disks.

Question 6

Which of the following microbes is a yeast?

A)Streptococcus mutans
B)Trichomonas vaginalis
C)Candida albicans
D)Staphylococcus aureus

Question 7

Which of the following bacterial structures interferes with phagocytosis?

A)Cell wall
B)Flagellum
C)Cytoplasmic membrane
D)Capsule

Question 8

Viruses multiply:

A)in the absence of nutrients.
B)only when they are inside of living cells.
C)when they are outside of living cells.
D)only when the temperature is below 7°

Question 9

Probably the surest way to kill bacteria (or any other type of microorganisms) in the shortest amount of time is to expose them to _____ temperatures.

A)sterilizing
B)freezing
C)fluctuating
D)refrigerator

Question 10

Obligate anaerobes grow best in the _____ of oxygen.

A)presence of large amounts
B)presence of medium amounts
C)presence of small amounts
D)absence

Question 11

A yeast is what type of microorganism?

A)Bacterium
B)Fungus
C)Virus
D)Protozoan

Question 12

The main function of bacterial fimbriae is to:

A)control the exit of wastes from the cell.
B)protect against crushing.
C)allow the cell to attach to surfaces.
D)protect against drying.

Question 13

Which of the following bacterial structures helps the cell to attach to surfaces?

A)Cell wall
B)Capsule
C)Cytoplasmic membrane
D)Fimbriae

Question 14

Which of the following groups of bacteria grow best inside your refrigerator?

A)Psychrophiles
B)Thermophiles
C)Mesophiles
D)Acidophils

Question 15

Thrush is caused by:

A)Candida albicans.
B)Streptococcus mutans.
C)Staphylococcus aureus.
D)human herpesvirus 1.

Question 16

Psychrophilic bacteria grow best under which of the following conditions?

A)In the human body
B)In hot water heaters
C)Anywhere the temperature is 37° C
D)In the refrigerator

Question 17

Acidogenic bacteria are noted for producing large amounts of:

A)acids.
B)vitamins.
C)proteins.
D)carbohydrates.

Question 18

Anaerobes are bacteria that:

A)require oxygen for growth.
B)grow only in the absence of oxygen.
C)can multiply in the presence or absence of oxygen.
D)are killed in the presence or absence of oxygen.

Question 19

Which of the following microbes is a type of fungus?

A)Influenzae
B)Candida albicans
C)Trichomonas vaginalis
D)Streptococcus mutans

Question 20

The main function of the bacterial cell wall is to:

A)protect against drying.
B)protect against crushing.
C)to control the exit of wastes from the cell.
D)provide the cell with locomotion.

Question 21

_____ acid is the final product from the bacterial fermentation of sugar (e.g., glucose).

A)Nucleic
B)Lactic
C)Hydrochloric
D)Pyruvic acid

Question 22

Viruses cause diseases in humans because they:

A)produce exotoxins.
B)produce endotoxins.
C)invade and kill or damage cells in our body.
D)"swim" away from phagocytes using their flagella.

Question 23

What is the result of a virus invading a host cell?

A)There is no effect on the cell.
B)The virus always dies.
C)The host cell always dies.
D)The host cell may die or be damaged.

Question 24

Which of the following are special cells that form during adverse conditions and are highly resistant to killing by heat and chemicals?

A)Aerobes
B)Endospores
C)Viruses
D)Psychrophiles

Question 25

Which of the following bacteria can change into special forms that are dormant and are highly resistant to heat, chemicals, and drying?

A)Rickettsia
B)Endospores
C)Mold
D)Vegetative cells

Question 26

How are bacterial spores important in dental infection control?

A)They cause periodontal disease.
B)They are used to monitor surface disinfection.
C)They are used to test the functioning and use of sterilizers.
D)They cause thrush.

Question 27

Agents that prevent bacterial growth without killing them are referred to as _____ agents.

A)bacteriostatic
B)sterilant
C)disinfectant
D)nucleic acid

Question 28

Which of the following represents the pH values of acid?

A)0 to 7
B)7 to 14
C)8 to 10
D)10 to 12

Question 29

Which of the following diseases is a bacterial disease?

A)Influenza
B)Hepatitis B
C)Mumps
D)Dental caries

Question 30

A bacterium that survives at low pH is called:

A)acidic.
B)anaerobic.
C)aciduric.
D)acidogenic.

Question 31

The genes of a virus are in the:

A)capsid.
B)nucleic acid core.
C)envelope.
D)capsid and envelope.

Question 32

Before a virus multiplies inside of our body cells, what must it do?

A)Uncoat (shed its capsid).
B)Assemble the capsid and nucleic acid to make a whole virus.
C)Adsorb (attach) to the host cell.
D)Kill the host cell.

Question 33

During the life cycle of a virus, what is the next step after the virus attaches to the host cell?

A)Uncoating
B)Release
C)Replication
D)Enters the cell

Question 34

Which of the following bacteria are important in metabolizing sugar to acids that cause dental caries?

A)Geobacillus stearothermophilus
B)Bacillus atrophaeus
C)Clostridium sporogenes
D)Streptococcus mutans

Question 35

Which type of microbe is the most difficult to kill?

A)Endospores
B)Vegetative bacteria
C)Viruses
D)Chlamydiae

Question 36

Which of the following microbes cannot be killed with antibiotics?

A)Streptococcus mutans
B)Staphylococcus aureus
C)Human herpes virus type 1
D)Mycobacterium tuberculosis

Question 37

Agar is a polysaccharide from seaweed that is used to:

A)kill bacteria.
B)grow viruses.
C)kill viruses.
D)culture bacteria.

Question 38

Chlamydia and Rickettsia are examples of:

A)viruses.
B)fungi.
C)bacteria.
D)protozoa.

Question 39

Colony-forming units (CFUs) are defined as:

A)measurements of the diameter of colonies that develop on an agar medium.
B)individual bacterial cells or a small group of cells, each of which can form a colony on agar media.
C)units used to estimate the distance a bacterial cell can move away from its colony on agar media.
D)highly resistant forms of certain bacteria.

Question 40

Which of the following substances is a component of some bacterial outer membranes and, when released in the human body, contributes to the causes of periodontal disease?

A)Lysozyme
B)Mesosome
C)Capsid
D)Endotoxin

Question 41

Bacterial growth is defined as an increase in cell numbers.

Question 42

For growth, all bacteria need the proper nutrients, temperature, pH, atmosphere, and _________.

Question 43

Unlike bacterial diseases, most viral diseases cannot be successfully treated.

Question 44

Bacteria are larger than viruses.

Question 45

If bacteria grow in a broth culture, the broth remains clear.

Question 46

Human viruses are smaller than bacteria.