Deck 4: Bacteria and Archaea

Question 1

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

Answer 1

B

Question 2

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

Answer 2

E

Question 3

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.

Answer 3

C

Question 4

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 biofilm.When you use confocal microscopy to image the biofilm,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 confocal microscope is out of adjustment.
B) the biofilm is no longer a pure culture of the microbe.
C) the biofilm culture was not incubated under the appropriate conditions.
D) the microenvironments within a biofilm promote structural variation.

Question 5

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

Question 6

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

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

Question 7

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

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

Question 8

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

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

Question 9

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 find that in some cases,the cells appear as coccobacillus,but in others,they can be filamentous,cocci,or club-shaped.The best explanation for this observation is that

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

Question 10

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

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

Question 11

Researchers studying the rigidity and flexibility 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 flexible cell envelope because

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

Question 12

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.
2-20-13

Question 13

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

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

Question 14

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

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

Question 15

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 bacteria were taken from an inappropriate medium, and a chemical is interfering with proper staining of the cells.
B) 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.
C) The specimen did not undergo heat fixation before staining; therefore, the primary dye does not stick properly to the wall.
D) These are mutant bacteria which cannot be stained like other bacteria.

Question 16

Serological analysis for bacterial identification typically involves using

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

Question 17

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

Question 18

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

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

Question 19

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

Question 20

Which of the following is mismatched?

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

Question 21

The function of bacterial endospores is

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

Question 22

Bacterial endospores are produced by ______.

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

Question 23

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

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

Question 24

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

Question 25

The reference for bacterial descriptions and classifications is _____ Manual of Systematic Bacteriology.

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

Question 26

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

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

Question 27

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

A) Nucleoid
B) Cell wall
C) Biofilm
D) Capsule
E) Endospore

Question 28

All of the following occur during endospore germination except

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

Question 29

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

Question 30

Plasmids

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

Question 31

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

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

Question 32

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

Question 33

Which of the following is mismatched?

A) Psychrophiles - adapted to very low temperatures
B) Extreme halophiles - adapted to salty habitats
C) Methanogens - convert CO₂ and H₂ into methane
D) Hyperthermophiles - adapted to high temperatures
E) Thermoplasmas - adapted to warm-blooded animal environments

Question 34

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

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

Question 35

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 36

All bacterial cells have ______.

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

Question 37

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

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

Question 38

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

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

Question 39

The chromosome in bacteria and archaea

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

Question 40

Magnetosomes are

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

Question 41

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 42

Lysozyme is most effective against ______.

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

Question 43

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

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

Question 44

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

Question 45

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

Question 46

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

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

Question 47

The chemical components of ribosomes are proteins and ______.

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

Question 48

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

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

Question 49

Peptidoglycan is a unique macromolecule found in bacterial ______.

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

Question 50

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

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

Question 51

Lipopolysaccharide is an important cell envelope component of ______.

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

Question 52

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

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

Question 53

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 54

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

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

Question 55

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

Question 56

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

A) cell membrane
B) flagella
C) cell wall
D) ribosomes

Question 57

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

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

Question 58

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

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

Question 59

Which of the following does not pertain to endotoxin?

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

Question 60

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

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

Question 61

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

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

Question 62

Which external structure protects bacteria from phagocytosis?

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

Question 63

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

A) hook, basal body, and filament
B) filament, hook, and basal body
C) filament, basal body, and hook
D) basal body, hook, and filament
E) basal body, filament, and hook

Question 64

Chemotaxis refers to the ability of a cell to

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

Question 65

Two functions of bacterial appendages are ______ and ______.

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

Question 66

Flagella move in a whip-like motion.

Question 67

A nutrient binds to receptors near the flagellar basal body.This will result in

A) inhibition of flagella rotation.
B) numerous tumbles.
C) clockwise rotation of flagella.
D) counterclockwise rotation of flagella.

Question 68

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

A) actin filaments; phospholipid membranes
B) lipopolysaccharide; techoic acid
C) endospores; metachromatic granules
D) fimbriae; capsules
E) pili; ribosomes

Question 69

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

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

Question 70

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

Question 71

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

Question 72

The basal body of a flagellum is anchored into the ______.

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

Question 73

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

A) periplasmic flagella (axial filaments)
B) flagella
C) fimbriae
D) cilia
E) pili

Question 74

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

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

Question 75

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

A) periplasmic flagella (axial filaments)
B) fimbriae
C) sex pili
D) cilia
E) flagella

Question 76

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

Question 77

Spirochetes are able to move due to ______.

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

Question 78

A bacterial cell exhibiting chemotaxis must have ______.

A) a capsule
B) flagella
C) thylakoids
D) metachromatic granules
E) fimbriae

Question 79

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

Question 80

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.