Deck 4: Bacteria and Archaea

Question 1

Researchers studying the rigidity and fexibility of the cell envelope used chemotaxis to measure the ability of microbes to squeeze through tight spaces. E. coli, a gram-negative bacterium, was able to traverse narrower channels than B. subtilis, a gram-positive microbe, even though both cells are the same size when grown without restriction. E. coli has the more fexible cell envelope because _______.

A) it has fewer flagella
B) there are fewer protein receptors
C) it has only a single membrane
D) lipopolysaccharide has no charge
E) there is less structural carbohydrate

Answer 1

there is less structural carbohydrate

Question 2

A clinical laboratory that identi?es the bacterial agents that cause human disease would refer to Bergey's Manual of ______ Bacteriology for guidance in identi?cation.

A) Evolutionary
B) Classical
C) Systematic
D) Determinative

Answer 2

Determinative

Question 3

Archaea have been found in many microenvironments in the human body. Which of the following microenvironments is most likely to ?t with the designation of Archaea as "extremophiles?"

A) The gingiva and the gut are anaerobic.
B) The inner ear can withstand increased pressure.
C) The temperature of the testes is less than 37°C.
D) The surface of the tongue has salt receptors.

Answer 3

The gingiva and the gut are anaerobic.

Question 4

In which situation would a bacterium most likely have cytoplasmic inclusions?

A) When the cell is synthesizing ?agella
B) In a habitat abundant in nutrients
C) When the cell is starved for nutrients
D) When producing an endospore

Question 5

E. coli has been isolated and cultured from three different individuals. Upon biochemical testing of these three cultures, you ?nd that there are differences in some reactions. What is the best explanation of these differences?

A) The other two cultures are not really E. coli.
B) Two of the cultures are mutants of the other.
C) Mistakes have been made in the test interpretation.
D) This is normal genetic variation seen among strains of E. coli.
E) These represent three different species of E. coli.

Question 6

Serological analysis for bacterial identi?cation typically involves using _______.

A) speci?c antibodies to the bacterial cell antigens
B) the determination of guanine + cytosine base concentrations
C) methods to identify cell enzymes
D) the analysis of the appearance of colonies
E) a microscope to determine cell morphology

Question 7

A research laboratory that identi?es the subspecies of bacterial isolates from a recent Salmonella epidemic would refer to Bergey's Manual of ______ Bacteriology for guidance in identi?cation.

A) Systematic
B) Determinative
C) Classical
D) Evolutionary

Question 8

Which of the following is mismatched?

A) Firmicutes - gram-positive cell walls
B) Tenericutes - waxy, acid-fast cell walls
C) Mendosicutes - archaea cell walls
D) Gracilicutes - gram-negative cell walls

Question 9

Which of the following bacteria is not closely related to the others?

A) Salmonella bongori
B) Salmonella enterica subsp. enterica
C) Salmonella enterica subsp. arizonae
D) Salmonella enterica subsp. indica

Question 10

You've just isolated a new bacterium in pure culture, and you culture it on a general purpose medium where its cells have a rod-shape (bacillus) morphology. In addition to culturing it on solid media, you inoculate a slide to grow it as a bio?lm. When you use confocal microscopy to image the bio?lm, you observe that there are several cellular morphologies, ranging from coccus to coccobacillus to long bacillus. The best explanation for this observation is that _______.

A) the bio?lm is no longer a pure culture of the microbe
B) the bio?lm culture was not incubated under the appropriate conditions
C) the microenvironments within a bio?lm promote structural variation
D) the confocal microscope is out of adjustment

Question 11

You've just isolated a new bacterium in pure culture, and you culture it on a general purpose medium where its cells have a coccobacillus morphology. When you examine the cells after culturing on a variety of differential media, you ?nd that in some cases, the cells appear a coccobacillus, but in others, they can be ?lamentous, cocci, or club-shaped. The best explanation for this observation is that _______.

A) the media were incubated at an incorrect temperature
B) the microscope is out of adjustment
C) the differential media are contaminated
D) the bacterium is pleomorphic
E) your culture has become contaminated

Question 12

You apply the acid-fast stain method to a patient's specimen, an aspirate from the lungs. Microscopic examination reveals a large number of bright pink-red bacillus-shaped bacteria in the Smear. Which statement is true?

A) This is the expected outcome for normal sputum.
B) The patient has pneumonia.
C) The patient has tuberculosis.
D) The patient has an HIV infection.

Question 13

You need to determine if a pure culture of bacteria is gram-positive or gram-negative, but you've just spilled your only solution of crystal violet so you can't do a Gram stain. You decide to try a lysozyme treatment on a sample of each culture and then examine the samples under the microscope. The expected result is _______.

A) gram-negatives will lyse and appears as debris; gram-positives will be unaffected
B) gram-positives will lyse and appears as debris; gram-negatives will lose cellular morphology and appear as cocci
C) gram-positives will lyse and appears as debris; gram-negatives will lyse but more slowly
D) gram-positives will lyse and appears as debris; gram-negatives will be unaffected
E) gram-negatives will lyse and appears as debris; gram-positives will lose cellular morphology and appear as cocci

Question 14

If you observe rod-shaped, pink cells on a slide that had just been Gram stained, you can assume that their cell envelope contains endotoxin.

Question 15

A new drug is found to act by blocking the incorporation of subunits into sterol molecules for the cell membrane. Which statement is true?

A) This kind of drug would destroy viruses only.
B) Only bio?lms would be affected by this drug.
C) A drug with this mechanism would be an excellent antibiotic.
D) Only archaeal cells would be affected by this drug.
E) Most bacteria would be unaffected by this drug.

Question 16

The process of sporangium formation and endospore maturation requires 6-8 hours. What is most likely to result if the temperature of the environment was raised to 100°C about 2 hours after the process started?

A) The endospore would form properly but would be unable to germinate.
B) The endospore would not form properly because it is not yet heat resistant.
C) The endospore would form more slowly and be heat resistant.
D) The chromosome in the endospore would likely carry mutations.
E) The organism would be termed a hyperthermophile.

Question 17

You have made a smear of a bacterial culture and have performed the Gram stain on it. Looking at the organism under the microscope, you notice that the cells do not seem to be the dark blue- Purple of a gram-positive reaction, but instead are light purple. Your staining procedure was Performed correctly. What is your best explanation as to why the bacteria have stained this way?

A) The specimen did not undergo heat ?xation before staining; therefore, the primary dye does not stick properly to the wall.
B) These are mutant bacteria which cannot be stained like other bacteria.
C) There is something in the wall of the bacteria that has affected the uptake of the crystal violet into the cell wall, thereby staining it improperly.
D) The bacteria were taken from an inappropriate medium, and a chemical is interfering with proper staining of the cells.

Question 18

At present, the most accurate indicator of evolutionary relatedness among organisms is the _______.

A) similarities of cell membrane proteins
B) size of the ribosomes
C) size of the periplasmic space
D) size of the bacterial chromosome
E) sequence of the ribosomal small subunit RNA

Question 19

A patient has a serious respiratory infection. A sputum sample yielded a bacterium that did not have any peptidoglycan. You hypothesize that the identity of this microbe could possibly be ______.

A) Mycobacterium tuberculosis
B) Streptococcus pneumoniae
C) Mycoplasma pneumoniae
D) Borrelia burgdorferi
E) Staphylococcus aureus

Question 20

You have found a mutant of Streptococcus pneumoniae that has lost the ability to produce a capsule. If you inject this strain into a population of healthy mice, what prediction can you make About the consequences?

A) The mice will die of pneumonia.
B) The mice will remain healthy.
C) The infection will respond to antiviral medication.
D) The mice will get a severe case of pneumonia and recover.

Question 21

Which of the following bacterial structures is incorrectly matched with a function?

A) Ribosomes - protein synthesis
B) Cytoplasm - dense, gelatinous solution
C) Nucleoid - hereditary material
D) Plasmids - contain genes essential for growth and metabolism
E) Inclusions - excess cell nutrients and materials

Question 22

Plasmids _______.

A) are located in microcompartments
B) are essential for survival
C) often carry genes controlling pathogenicity
D) cannot be passed between organisms
E) are found in all bacteria

Question 23

Bacterial endospores are produced by ______.

A) Mycoplasma
B) Entamoeba
C) Bacillus
D) Staphylococcus

Question 24

Magnetosomes are _______.

A) composed of magnetic iron oxide particles
B) infoldings of the cell membrane
C) found in all bacteria and some archaea
D) responsible for the heat resistance of endospores
E) also termed metachromatic granules

Question 25

All of the following structures contribute to the ability of pathogenic bacteria to cause disease except ______.

A) gram-negative outer membrane
B) ?mbriae
C) inclusions
D) capsule
E) slime layer

Question 26

The chromosome in bacteria and archaea _______.

A) contains all the cell's plasmids
B) is located in the cell membrane
C) is part of the nucleoid
D) forms a single linear strand of DNA

Question 27

Which of the following is mismatched?

A) Hyperthermophiles - adapted to high temperatures
B) Extreme halophiles - adapted to salty habitats
C) Psychrophiles - adapted to very low temperatures
D) Thermoplasmas - adapted to warm-blooded animal environments
E) Methanogens - convert CO? and H2 into methane

Question 28

Endospores of certain bacterial species can enter tissues in the human body, germinate, and cause an infectious disease.

Question 29

All of the following occur during endospore germination except _______.

A) dehydration of the cell components
B) binding of a small organic molecule to initiate germination
C) the cell grows out of its protein coats
D) enzymes digest the endospore cortex

Question 30

The reference for bacterial descriptions and classi?cations is _____ Manual of Systematic Bacteriology.

A) Pasteur's
B) Koch's
C) Bergey's
D) Leeuwenhoek's
E) Lister's

Question 31

All bacterial cells have ______.

A) capsules
B)flagella
C) a chromosome
D) the ability to produce endospores
E) an S-layer

Question 32

The most immediate result of destruction of a cell's ribosomes would be that _______.

A) holes would appear in the capsule
B) the chromosome would unravel
C) protein synthesis would stop
D) material would not cross the cell membrane
E) glycogen inclusions would form

Question 33

Boiling water (100°C) can normally destroy endospores.

Question 34

Archaea do not have the typical peptidoglycan structure found in bacterial cell walls.

Question 35

The function of bacterial endospores is _______.

A) reproduction and growth
B) protection of genetic material during harsh conditions
C) to provide a protected site for photosynthesis
D) storage of excess cellular building blocks

Question 36

Endospores are _______.

A) metabolically inactive
B) resistant to heat and chemical treatments
C) resistant to destruction by radiation
D) living structures
E) All of the choices are correct.

Question 37

Halobacterium salinarum lives in and requires a high salt concentration. This is an example of an archaeon described as a ______.

A) barophile
B) psychrophile
C) halophile
D) thermophile

Question 38

Which of the following is not a phenotypic trait of bacteria?

A) rRNA sequence
B) Nutrient requirements
C) Biochemical reactions
D) Cell shape

Question 39

The site for ATP synthesis in bacterial cells is the ______.

A) cell membrane
B) ribosome
C) mitochondrion
D) cell wall
E) microcompartment

Question 40

Chemical analysis of a bacterial cell detects dipicolinic acid. What is the identity of this structure?

A) Endospore
B) Nucleoid
C) Bio?lm
D) Cell wall
E) Capsule

Question 41

The cell envelope or its parts can interact with human tissue and cause disease.

Question 42

The chemical components of ribosomes are proteins and ______.

A) mRNA
B) tRNA
C) rRNA
D) DNA

Question 43

Peptidoglycan is a unique macromolecule found in bacterial ______.

A) cell membranes
B) cell walls
C) capsules
D) slime layers
E) inclusions

Question 44

The outcome of the Gram stain is based on differences in the ______.

A) ribosomes
B) cell membrane
C) ?agella
D) cell wall

Question 45

Mycobacterium and Nocardia are different from most gram-positive bacteria in that their cell walls _______.

A) are easily decolorized during staining
B) contain unique, waxy lipids
C) contain a layer of lipopolysaccharide
D) contain more peptidoglycan

Question 46

A bacterial genus that has waxy mycolic acid in the cell walls is ______.

A) Bacillus
B) Corynebacterium.
C) Mycobacterium
D) Streptococcus
E) Mycoplasma

Question 47

A bacterial cell wall that has primarily peptidoglycan with small amounts of teichoic acid and lipoteichoic acid is ______.

A) gram-positive
B) a protoplast
C) a spheroplast
D) gram-negative
E) acid-fast

Question 48

Which of the following does not pertain to endotoxin?

A) Endotoxin can stimulate fever in the human body.
B) Endotoxin can cause septic shock in the human body.
C) Endotoxin is a bacterial cell wall lipid.
D) Endotoxin is found in acid-fast bacterial cell walls.

Question 49

Lipopolysaccharide is an important cell envelope component of ______.

A) mycoplasmas
B) gram-negative bacteria
C) acid-fast bacteria
D) gram-positive bacteria
E) protoplasts

Question 50

If bacteria living in salty seawater were displaced to a freshwater environment, the cell structure that would prevent the cells from rupturing is the ______.

A) capsule
B) cell membrane
C) cell wall
D) slime layer
E) endospore

Question 51

Mycobacterium and Nocardia are distinguished from other bacteria by the ______ stain.

A) Gram
B) basic
C) methylene blue
D) acid-fast
E) endospore

Question 52

The macromolecule containing alternating N-acetylglucosamine (NAG) and N-acetylmuramic acid (NAM) chains cross-linked by short peptide fragments is ______.

A) teichoic acid
B) peptidoglycan
C) lipopolysaccharide
D) mycolic acid
E) lysozyme

Question 53

Which of the following is not true of the outer membrane?

A) The innermost layer is a phospholipid bilayer.
B) Porins create channels through the outer membrane.
C) The uppermost layer is made of lipopolysaccharide.
D) The lipid portion of the lipopolysaccharide layer is termed endotoxin.
E) Gram-positive bacteria have an outer membrane.

Question 54

The cell membrane, the cell wall, and the outer membrane comprise the ______.

A) S-layer
B) glycocalyx
C) slime layer
D) peptidoglycan
E) cell envelope

Question 55

Gram-negative bacteria _______.

A) have a more complex cell envelope with a greater variation in chemical composition
B) appear purple following the Gram stain
C) are generally more susceptible to antibiotics than gram-positive bacteria
D) include all pathogens

Question 56

Which is the correct order for the application of reagents in the Gram stain?

A) Safranin, crystal violet, alcohol/acetone, iodine
B) Crystal violet, safranin, iodine, alcohol/acetone
C) Crystal violet, alcohol/acetone, iodine, safranin
D) Crystal violet, iodine, alcohol/acetone, safranin
E) Iodine, safranin, crystal violet, alcohol/acetone

Question 57

The chemical bonds in peptidoglycan can be hydrolyed by the enzyme _____, found in tears and saliva.

A) kinase
B) peptidase
C) lysozyme
D) penicillinase

Question 58

During the Gram stain, the application of alcohol results in the decolorization of ______ cells.

A) gram-positive
B) gram-negative
C) all
D) pleomorphic

Question 59

Some bacteria have a cytoskeleton of sterols to help maintain their shape.

Question 60

Lysozyme is most effective against ______.

A) gram-positive organisms
B) mycoplasmas
C) gram-negative organisms
D) cyanobacteria
E) archaea

Question 61

The term that refers to the presence of ?agella all over the cell surface is ______.

A) atrichous
B) peritrichous
C) monotrichous
D) amphitrichous
E) lophotrichous

Question 62

A bacterial cell exhibiting chemotaxis must have ______.

A) ?mbriae
B) metachromatic granules
C) thylakoids
D) ?agella
E) a capsule

Question 63

The term that refers to ?agella at both poles of the cell is ______.

A) peritrichous
B) atrichous
C) amphitrichous
D) monotrichous
E) lophotrichous

Question 64

If the bacterial cells were viewed immediately after crystal violet was applied during the Gram stain procedure, gram-positive cells would be purple but gram-negative cells would be colorless.

Question 65

Which external structure protects bacteria from phagocytosis?

A) Slime layer
B) Cell membrane
C) Capsule
D) Fimbriae

Question 66

Both gram-positive and gram-negative cells have outer membranes.

Question 67

The basal body of a ?agellum is anchored into the ______.

A) cell wall
B) outer membrane
C) cell membrane
D) peptidoglycan layer
E) hook

Question 68

The term that refers to the presence of a tuft of ?agella emerging from a single site is ______.

A) atrichous
B) monotrichous
C) peritrichous
D) amphitrichous
E) lophotrichous

Question 69

Chemotaxis refers to the ability of a cell to _______.

A) move in response to a chemical
B) halt movement in response to a chemical
C) transport desired molecules into a cell
D) move in response to light

Question 70

Hot carbol fuchsin is the primary dye in the acid-fast stain.

Question 71

A nutrient binds to receptors near the ?agellar basal body. This will result in _______.

A) inhibition of ?agella rotation
B) clockwise rotation of ?agella
C) counterclockwise rotation of ?agella
D) numerous tumbles

Question 72

Spirochetes are able to move due to ______.

A) glycocalyx for gliding motility
B) a membrane-bound ?agellum
C) pseudopods
D) a periplasmic ?agellum
E) cilia serving as walking feet

Question 73

Two structures that allow bacteria to adhere to surfaces are ______ and ______.

A) actin ?laments; phospholipid membranes
B) pili; ribosomes
C) ?mbriae; capsules
D) endospores; metachromatic granules
E) lipopolysaccharide; techoic acid

Question 74

The bacterial ?agellum has three components. In order from the cytoplasm to the external environment, they are ______.

A) basal body, hook, and ?lament
B) ?lament, basal body, and hook
C) basal body, ?lament, and hook
D) hook, basal body, and ?lament
E) ?lament, hook, and basal body

Question 75

The short, numerous appendages used by some bacterial cells for adhering to surfaces are called ______.

A) cilia
B) ?agella
C) periplasmic ?agella (axial ?laments)
D) ?mbriae
E) pili

Question 76

The region between the bacterial cell membrane and the cell wall is called the outer membrane.

Question 77

Flagella move in a whip-like motion.

Question 78

Two functions of bacterial appendages are ______ and ______.

A) attachment; energy production
B) antibiotic resistance; motility
C) attachment; motility
D) motility; energy production

Question 79

The cell envelope of gram-positive bacteria has two layers: a thick cell wall and the cell membrane.

Question 80

The transfer of genes during bacterial conjugation involves rigid, tubular appendages called ______.

A) ?mbriae
B) cilia
C) ?agella
D) sex pili
E) periplasmic ?agella (axial ?laments)