Deck 1: Bacterial Cell Structure, physiology, Metabolism, and Genetics

Question 1

Name the numerous short projections that extend from the cell surface and are used for locomotion.

A) Flagella
B) Mitochondria
C) Cilia
D) Phospholipid

Answer 1

C
By definition,cilia are short projections extending from the cell surface and are used for locomotion,whereas flagella are longer projections used for locomotion.Mitochondria are cellular organelles responsible for electron transport and oxidative phosphorylation.Phospholipids are polar molecules that form the plasma membrane.

Question 2

The function of a cell wall is to:

A) Regulate the transport of macromolecules in and out of the cell.
B) Provide rigidity and strength to the exterior of the cell.
C) Provide reserve energy to the eukaryotic cell.
D) Protect the eukaryote from predators.

Answer 2

B
The plasma membrane regulates the transport of macromolecules in and out of the cell,not the cell wall.The mitochondria provide energy to the eukaryotic cell.Cell walls are not able to protect a eukaryotic cell from predators.

Question 3

Prokaryotic cells have which the following structures in their cytoplasm?

A) Golgi apparatus
B) Ribosome
C) Mitochondria
D) Endoplasmic reticulum

Answer 3

B
All the structures listed are found in eukaryotic cells,but the one that only applies to prokaryotic cells is the ribosome.

Question 4

To survive,microbial inhabitants have learned to adapt by varying all of the following EXCEPT:

A) Growth rate
B) Growth in all atmospheric conditions
C) Growth at particular temperatures
D) Bacterial shape

Question 5

A microbiology technologist performs a traditional bacterial stain on a colony from a wound culture that is suspected to contain bacteria from the genus Clostridium.The unstained areas in the bacterial cell observed by the technologist are called:

A) Cilia
B) Ribosomes
C) Spores
D) Mitochondria

Question 6

All of the following statements are true about viruses EXCEPT:

A) Viruses consist of DNA or RNA but not both.
B) Viruses are acellular but are surrounded by a protein coat.
C) Viruses can infect bacteria, plants, and animals.
D) Viruses do not need host cells to survive.

Question 7

In the laboratory,the clinical microbiologist is responsible for all the following EXCEPT:

A) Isolating microorganisms
B) Selecting treatment for patients
C) Identifying microorganisms
D) Analyzing bacteria that cause disease

Question 8

What structure is a phospholipid bilayer embedded with proteins and cholesterol that regulates the amount of chemicals that pass in and out of a cell?

A) Cell wall
B) Mitochondria
C) Endoplasmic reticulum
D) Plasma membrane

Question 9

Who was considered the father of protozoology and bacteriology?

A) Anton van Leeuwenhoek
B) Louis Pasteur
C) Carl Landsteiner
D) Michael Douglas

Question 10

A clinical laboratory scientist is working on the bench,reading plates,and notices that a culture has both a unicellular form and a filamentous form.What type of organism exhibits these forms?

A) Virus
B) Fungi
C) Bacteria
D) Parasite

Question 11

Why is the interior of the plasma membrane potentially impermeable to water-soluble molecules?

A) The hydrophobic tails of the phospholipid molecules are found there.
B) The hydrophilic tails of the phospholipid molecules are found there.
C) The ion channels are found there.
D) The cholesterol molecules in the plasma membrane are found solely in the interior of the membrane.

Question 12

This constituent of a gram-positive cell wall absorbs crystal violet but is not dissolved by alcohol,thus giving the gram-positive cell its characteristic purple color.

A) Mycolic acid
B) Cholesterol
C) Carbolfuchsin
D) Peptidoglycan

Question 13

Bacterial species that exhibit phenotypic differences are considered:

A) Biovarieties
B) Serovarieties
C) Phagevarieties
D) Subspecies

Question 14

A microorganism that is a unicellular organism and lacks a nuclear membrane and true nucleus is classified as:

A) Fungi
B) Virus
C) Algae
D) Parasite

Question 15

A clinical laboratory scientist is working in a microbiology laboratory where she receives a viral culture.Should she make a smear so that she can look at the virus under the light microscope?

A) No, viruses cannot be seen under an ordinary light microscope.
B) Yes, viruses can be seen under an ordinary light microscope.
C) Yes, viruses can be seen under a phase-contrast microscope.
D) No, viruses cannot be seen under a phase-contrast microscope.

Question 16

What enables the microbiologist to select the correct media for primary culture and optimize the chance of isolating a pathogenic organism?

A) Determining staining characteristics
B) Understanding the cell structure and biochemical pathways of an organism
C) Understanding the growth requirements of a particular bacterium
D) Knowing the differences in cell walls of particular bacteria.

Question 17

Mycobacteria have a gram-positive cell wall structure with a waxy layer containing these two compounds.

A) Glycolipids and mycolic acid
B) Glycolipids and phospholipids
C) Mycolic acid and lipopolysaccharides
D) Lipopolysaccharides and phospholipids

Question 18

This type of chromosomal DNA is found in eukaryotic cells.

A) Linear
B) Circular
C) Plasmid
D) Colloid

Question 19

The nuclear membrane in prokaryotes is:

A) Missing
B) Impenetrable
C) A classic membrane
D) A lipid bilayer membrane

Question 20

Diagnostic microbiologists emphasize placement and naming of bacterial species into all the following categories EXCEPT:

A) Order
B) Family
C) Genus
D) Species

Question 21

When performing a Gram stain on a gram-negative organism,the crystal violet is absorbed into this outer cell wall layer then washed away with the acid alcohol.What is the main component of the outer layer of the cell wall?

A) Peptidoglycan
B) Mycolic acid
C) N-acetyl-d-muramic acid
D) Lipopolysaccharide

Question 22

What stain is used to stain medically important fungi?

A) Methylene blue
B) Acridine orange
C) Acid-fast
D) Lactophenol cotton blue

Question 23

Mycoplasma and Ureaplasma spp.must have media supplemented with serum or sugar as nutrients and because:

A) Their cell walls contain only peptidoglycan.
B) They lack cell walls.
C) The sterols in their cell walls are soluble in normal bacterial media.
D) Their cell walls contain detoxifying enzymes.

Question 24

All the following environmental factors influence the growth of bacteria EXCEPT:

A) Moisture
B) pH
C) Temperature
D) Gaseous composition of the atmosphere
E) All of the above environmental factors influence the growth of bacteria

Question 25

What type of fermentation produces lactic,acetic,succinic,and formic acids as the end products?

A) Butanediol
B) Propionic
C) Mixed acid
D) Homolactic

Question 26

When bacteria are growing,they go through a log phase when:

A) They are preparing to divide.
B) Nutrients are becoming limited and the numbers of bacteria remain constant.
C) The number of nonviable bacterial cells exceeds the number of viable cells.
D) The bacteria numbers usually double with each generation time

Question 27

The three basic shapes of bacteria include all the following EXCEPT:

A) Spirochetes
B) Cell-wall deficient
C) Cocci
D) Bacilli

Question 28

Some Clostridium sp.are examples of this class of organism because they can live in the presence of oxygen but do not use oxygen in its metabolic processes.

A) Microaerophilic
B) Aerotolerant anaerobe
C) Obligate anaerobe
D) Facultative anaerobe

Question 29

What is the purpose of a capsule?

A) Prevent osmotic rupture of the cell membrane
B) Make up the periplasmic space
C) Act as a virulence factor in helping the pathogen evade phagocytosis
D) Provide an attachment site for somatic antigens.

Question 30

If bacteria utilize various carbohydrates for growth,it is usually detected by:

A) Alkaline production and change of color from the pH indicator
B) Production of carbon dioxide
C) Production of keto acids
D) Acid production and change of color from the pH indicator

Question 31

These bacteria cannot grow in the presence of oxygen.

A) Obligate aerobes
B) Capnophilic organisms
C) Facultative anaerobes
D) Obligate anaerobe

Question 32

The outer cell wall of the gram-negative bacteria serves three important functions,which includes all the following EXCEPT:

A) It provides an attachment site for the flagella, which will act in locomotion.
B) It acts as a barrier to hydrophobic compounds and harmful substances.
C) It acts as a sieve.
D) It provides attachment sites that enhance adhesion to host cells.

Question 33

The Gram stain is a routine stain used in bacteriology to determine gram-positive and gram-negative bacteria based on the:

A) Phenotypic characteristics of the organism
B) Composition of the bacterial cell wall
C) Composition of the bacterial cell membrane
D) Composition of the bacterial pili

Question 34

All the following are types of media EXCEPT:

A) Selective
B) Differential
C) Fastidious
D) Transport

Question 35

The three regions of the lipopolysaccharide include all the following EXCEPT:

A) Antigenic O-specific polysaccharide
B) Mycolic acid
C) Core polysaccharide
D) Endotoxin (inner lipid A)

Question 36

The laboratory receives a specimen in which the doctor suspects that the infecting organism is Haemophilus influenzae.This organism grows best in an atmosphere that contains 5% to 10% carbon dioxide.It is classified as what type of bacteria?

A) Obligate aerobe
B) Capnophilic
C) Facultative anaerobe
D) Obligate anaerobe

Question 37

Some bacteria grow at 25° C or 42° C,but diagnostic laboratories routinely grow pathogenic bacteria at what temperature?

A) 30° C
B) 60° C
C) 35° C
D) 10° C

Question 38

In what staining procedure does carbolfuchsin penetrate the bacterial cell wall through heat or detergent treatment?

A) Gram stain
B) Acridine orange stain
C) Endospore stain
D) Acid-fast stain

Question 39

Which is a biochemical process carried out by both obligate and facultative anaerobes?

A) Fermentation
B) Respiration
C) Oxidation
D) Reduction

Question 40

Diagnostic schemes in the microbiology laboratory typically analyze each unknown bacterium's metabolic processes for all the following EXCEPT:

A) Utilization of a variety of substrates as carbon sources
B) Energy utilization for metabolic processes
C) Production of specific end products from specific substrates
D) Production of an acid or alkaline pH in the test medium

Question 41

These are enzymes that cut the bacterial DNA at specific locations.

A) Bacteriophage enzymes
B) Restriction enzymes
C) Temperate lysogeny enzymes
D) Conjugation enzymes

Question 42

Lysogeny occurs when:

A) Genes present in the IS element are expressed in the bacterial cell.
B) Genetic material is transferred from one bacterium to another through a sex pilus.
C) Competent bacteria cells take up naked DNA.
D) Genes present in the bacteriophage DNA are incorporated into the bacteria's genome.

Question 43

Genes that code for antibiotic resistance are often found on extracellular,small,circular pieces of DNA.These DNA pieces are called:

A) Plasmids
B) Phenotypes
C) Chromosomes
D) Genomes

Question 44

In the medical microbiology laboratory,a gram-negative bacterium's ability to ferment this sugar is the first step in its identification.

A) Sucrose
B) Mannitol
C) Trehalose
D) Lactose

Question 45

A _____ is a single,closed,circular piece of DNA that is supercoiled to fit inside the cell.

A) Phenotype
B) Chromosome
C) Frame-shift mutation
D) Transposon

Question 46

What process involves transferring or exchanging genes between similar regions on two separate DNA molecules?

A) IS element
B) Replication
C) Recombination
D) Transcription

Question 47

A microbiologist is working with two separate cultures of the same organism.The bacteria in one culture are resistant to penicillin,whereas the bacteria in the other culture are susceptible to penicillin.The bacteria from both cultures are mixed together,and all the resulting bacteria are resistant to penicillin.What caused this phenomenon?

A) The plasmid carrying the resistance gene was transferred to the susceptible population of bacteria.
B) The plasmid carrying the susceptibility gene was transferred to the resistant population of bacteria.
C) An IS element was inserted into the genome of the susceptible bacterial population.
D) A frame-shift mutation occurred that allowed the susceptible population of bacteria to develop resistance to penicillin.

Question 48

Diphtheria is a disease produced by Corynebacterium diphtheriae.However,not all C.diphtheriae bacteria produce the toxin that causes this disease.To produce the toxin,the bacteria must first become infected with a bacteriophage.The process by which bacterial genes are transferred to new bacteria by the bacteriophage is called:

A) Conjugation
B) Transduction
C) Replication
D) Transformation