Deck 3: The Bacterial Cell

Question 1

Which of the following microscopes operates based on the absorption of light at one wavelength and its emission at a longer wavelength?

A) Atomic force
B) Phase contrast
C) Darkfield
D) Fluorescent

Answer 1

Fluorescent

Question 2

Heterotrophic organisms derive their energy from oxidation of

A) inorganic molecules.
B) organic molecules.
C) carbon dioxide.
D) light.

Answer 2

organic molecules.

Question 3

The flagellar arrangement of Vibrio cholerae, as seen in the image provided, can be described as
Source: CDC and Dr. William A. Clark

A) monotrichous.
B) amphitrichous.
C) lophotrichous.
D) peritrichous.

Answer 3

monotrichous.

Question 4

When creating a bacterial growth curve, what data is necessary?

A) Number of living organisms and number of generations
B) Number of dead organisms and doubling time
C) Number of living cells and doubling time
D) Number of dead cells and generation time

Question 5

Organisms with fimbriae can be more pathogenic because it allows them to

A) move to nutrients and optimal concentrations of oxygen.
B) resist phagocytosis.
C) survive attack by the human immune system.
D) adhere to body tissues.

Question 6

Which of the following cell wall components is shared by both gram-positive and gram-negative organisms?

A) Lipopolysaccharide
B) Peptidoglycan
C) Periplasmic space
D) Porins

Question 7

A microbiology student has walking pneumonia due to Mycoplasma pneumoniae. He decides to self-medicate with the leftover penicillin tablets he had from his last case of Streptococcus pyogenes. What is the fault in his thought process?

A) Penicillin is not routinely used to treat group A Streptococcus pharyngitis.
B) Mycoplasma pneumoniae does not possess porins to take in the antibiotic.
C) M. pneumoniae does not possess a cell wall.
D) Penicillin is destroyed due to beta-lactamase production by M. pneumoniae.

Question 8

A technologist inoculates a chocolate agar with a stock culture of Neisseria gonorrhoeae. She forgets to subculture the organism at 48 hours. At 72 hours, she realizes her mistake and subcultures the organism to a new chocolate agar. At 24 hours, the subculture is not growing. On a growth curve, the organism is displaying the

A) lag phase.
B) stationary phase.
C) exponential phase.
D) death phase

Question 9

Bacteria use metabolic pathways to create ATP for power much like gasoline. Which of the following pathways does not directly generate ATP as a by-product?

A) Pentose-phosphate cycle
B) Embden-Meyerhof pathway
C) Entner-Duodoroff pathway
D) Kreb's cycle

Question 10

E. coli is capable of using both respiration and fermentation. To produce the maximum amount of ATP, it should use

A) fermentation of glucose.
B) catabolism of glucose via the Entner-Duodoroff pathway.
C) oxidation of glucose.
D) anaerobic metabolism of glucose.

Question 11

The vanA gene causes vancomycin resistance in Enterococcus species. This gene can be passed to other organisms, such as methicillin-resistant Staphylococcus aureus, by all of the following means except

A) transformation.
B) transporons.
C) conjugation.
D) transduction.

Question 12

An organism that can grow in an environment with an alkaline pH, high salt concentration, and at a temperature of 0°C is described as

A) acidophilic, alkaliphilic, and thermophilic.
B) alkaliphilic, halophilic, and mesophlic.
C) acidophilic, mesophlic, and thermophilic.
D) alkaliphilic, halophilic, and psychrophilic.

Question 13

Saline, rather than fresh water, is used to prepare smears of bacteria for Gram stain because

A) saline has a lower osmotic pressure than the organism and the organism cell swells.
B) saline has a high solute concentration causing water to flow out of the cell and it shrinks.
C) fresh water rushes into the cell due to its low solute concentration and the cell swells.
D) fresh water affects the Gram stain reaction and causes inaccurate results.

Question 14

Lipid A is located

A) in the outer membrane of gram-negative organisms.
B) on the teichoic acid of gram-positive organisms.
C) on the porin proteins of both gram-positive and gram-negative organisms.
D) in the cytoplasmic membrane of gram-negative organisms.

Question 15

Binary fission determines an organism's

A) generation or doubling time.
B) length of lag time.
C) ability to conjugate.
D) cellular arrangement.

Question 16

In times of plenty, bacteria are able to store various substances within the cell (carbohydrate, ATP, or lipid reserves) by means of

A) endospores.
B) capsules.
C) bacteriophages.
D) inclusion bodies.

Question 17

Which metabolic pathway is the primary means of glucose metabolism by E. coli?

A) Embden-Meyerhof-Parnas pathway
B) Entner-Doudoroff pathway
C) Tricarboxylic acid (TCA) cycle
D) Pentose phosphate cycle

Question 18

Mutants that cannot grow on defined minimal medium without some nutritional additive are known as

A) selectable mutants.
B) nonselectable mutants.
C) prototrophs.
D) auxotrophs.

Question 19

DNA sequences within a single cell that are able to jump to different locations within a chromosome are called

A) plasmids.
B) bacteriophages.
C) transposons.
D) transconjugants.

Question 20

What is the toxic portion of the lipopolysaccharide component of gram-negative cell walls?

A) Lipid A
B) "O" antigen
C) Porins
D) Phospholipids