Microbiology Final

The term infection refers to

• contact with microorganisms.

• microorganisms colonizing the body.

• contact with pathogens.

• None of the choices are correct.

• pathogens penetrating host defenses

• pathogens penetrating host defenses

Which terminology is not used to describe members of the resident biota?

• Indigenous biota

• Pathogenic biota

• Commensals

• Normal microbiota

• Normal biota

• Pathogenic biota

Microorganisms can be identified from a patient sample using biochemical tests based on the premise that ________.

• organisms will not grow on certain media types and can be selected for on others

• bacteriophages infect certain bacterial cells and the specificity can be used to identify the organism

• organisms have a unique combination of metabolic enzymes that are displayed when color-changing dyes are utilized to demonstrate their physiological response to specific substrates

• organisms display specific antigens that can be bound by color-changing antibodies that allow the clinician to locate and identify the pathogen

• organisms have a unique combination of metabolic enzymes that are displayed when color-changing dyes are utilized to demonstrate their physiological response to specific substrates

Most fungi obtain nutrients from dead plants and animals. These fungi are called ________.

• saprophytes

• substrates

• parasites

• nonseptate

saprophytes

The type of microscope in which you would see brightly illuminated specimens against a black background is _____.

• dark field

• phase contrast

• fluorescence

• electron

• bright field

• dark field

The human microbiome is considered an important component of the first line of defense. Which statement adequately reflects its role as a defensive barrier?

• Cells in the human microbiome secrete cytokines that play a role in stimulating the immune response when a pathogen has entered the system.

• The human microbiome has evolved with the species so it is able to actively destroy pathogens by raising the body temperature when an infection by a pathogen occurs.

• The organisms that comprise the microbiota are able to phagocytose potential pathogens, thereby eliminating them from the human host.

• The human microbiota competes with pathogens for space and nutrients limiting their ability to cause infection, and trains the immune system to recognize antigens.

The human microbiota competes with pathogens for space and nutrients limiting their ability to cause infection, and trains the immune system to recognize antigens.

The cell's metabolic reactions involve the participation of ________ that lower the activation energy needed for the initiation of a reaction.

• vitamins

• coenzymes

• enzymes

• ATP

• cofactors

• enzymes

RNA molecules differ from DNA molecules because only RNA ________.

• has uracil

• does not have thymine

• has ribose

• is typically one strand of nucleotides

• All of the choices are correct.

• All of the choices are correct.

Opportunistic pathogens

• are always pathogens.

• have well-developed virulence factors.

• None of the choices is correct.

• cause disease in every individual.

• cause disease in compromised individuals.

• cause disease in compromised individuals.

Specimen collection ________.

• All of the choices are correct.

• must utilize aseptic techniques

• does not require special handling

• is always done by a medical professional

• must be done under sterile conditions

• must utilize aseptic techniques

Serological testing can be used to test each of the following except ________.

• cerebrospinal fluid

• blood serum

• saliva

• urine

• skin

• skin

Attime = 0, 200 ml of broth receives an initial inoculum of bacteria. 0.1 ml of the bacterial culture is taken from the culture at repeated intervals, diluted in liquid agar and spread on a plate containing solid media. After incubation, the plate from time = 420 min yields 62 colonies from the 0.1 ml sample. The total estimated number of cells in the flask at t = 420 min is _____.

• 62

• 12,400

• 26,040

• 124,000

• 124,000

The purpose of staining cells on a microscope slide is to ________.

• enlarge the cells

• secure them to the slide

• add contrast in order to see them better

• kill them

• see motility

• add contrast in order to see them better

The major histocompatibility complex is ________.

• located in the thymus gland

• All of the choices are correct.

• found on the third chromosome

• glycoproteins, called MHC antigens, found on all body cells

• a set of genes that code for MHC glycoproteins

• a set of genes that code for MHC glycoproteins

Which event is the process of releasing chemical mediators?

• Prostaglandins cause vasodilation and increased vascular permeability

• Degranulation

• Bonding of allergen to adjacent IgE binding sites on mast cells and basophils

• Binding of IgE by the Fc region to mast cells and basophils

• Histamine acts on smooth muscle

• Degranulation

An organism that uses CO2 for its carbon needs would be called a(n) ________.

• heterotroph

• autotroph

• chemoheterotroph

• saprobe

• autotroph

Leukocytes that are derived from monocytes and have long, thin processes to trap pathogens are ________.

• mast cells

• dendritic cells

• macrophages

• eosinophils

• platelets

• dendritic cells

The building blocks of an enzyme are ________.

• phosphate, glycerol, and fatty acids

• glycerol and fatty acids

• amino acids

• monosaccharides

• amino acids

Each nucleotide is composed of ________.

• two phosphates, one nitrogenous base, and two sugars

• two phosphates, one nitrogenous base, and one sugar

• one phosphate, one nitrogenous base, and two sugars

• one phosphate, one nitrogenous base, and one sugar

• one phosphate, two nitrogenous bases, and one sugar

• two phosphates, one nitrogenous base, and two sugars

  
  

The movement of molecules from an area of high concentration to an area of lower concentration is called ________.

Group of answer choices

active transport

facilitated diffusion

diffusion

osmosis

diffusion

Scrubbing or immersing the skin in chemicals to reduce the numbers of microbes on the skin is _____.

• disinfection

• antisepsis

• sterilization

• sanitization

• ionization

• antisepsis

The most efficient sterilizing conditions in a steam autoclave are ________.

• 71.6°C for 15 seconds

• 121°C at 15 psi for 15 minutes

• 100°C for 30 minutes

• 63°C for 30 minutes

• 160°C for 2 hours

• 121°C at 15 psi for 15 minutes

Bacteria living in a freshwater stream that are moved to salty seawater would ________.

• be in a hypotonic solution

• be in an isotonic solution

• shrivel

• None of the choices are correct.

• gain water

• shrivel

The benefit of specific immunity is the production of _______ that provide long-lasting protection.

• plasma cells

• memory cells

• antibodies

• phagocytotic cells

• T helper cells

• memory cells

Which of the following is not a major element of a microbial cell?

• Carbon

• Copper

• Nitrogen

• Hydrogen

• Oxygen

• Copper

Which method often results in colonies developing down throughout the agar along with some colonies on the surface?

• All of the choices are correct.

• Streak plate

• None of the choices are correct.

• Pour plate

• Spread plate

• Pour plate

The term that refers to the purposeful addition of microorganisms into a laboratory nutrient medium is _____.

• immunization

• contamination

• infection

• inoculation

• isolation

• inoculation

An organism with a temperature growth range of 45°C to 60°C would be called a(n) ________.

• thermophile

• extremophile

• psychrophile

• psychrotroph

• thermophile

The immunoglobulin class that is the only one capable of crossing the placenta is ________.

• IgG

• IgD

• IgA

• IgM

• IgE

• IgG

One nucleotide contains ________.

• All of the choices are correct

• one nitrogen base

• one phosphate

• None of the choices are correct.

• one pentose sugar

• All of the choices are correct

Which of the following is not a type of phagocyte?

• Monocyte

• Kupffer cell

• Neutrophil

• Macrophage

• Lymphocyte

• Lymphocyte

The eukaryote cell membrane is composed of _____.

• phospholipids

• proteins

• sterols

• cholesterol

• All of the choices are correct.

• All of the choices are correct.

The phase of the bacterial growth curve in which newly inoculated cells are adjusting to their new environment, metabolizing but not growing, is the _____.

• death phase

• lag phase

• stationary phase

• log phase

• prophase

• lag phase

Large quantities of antibodies that react to the second entry of antigen and lead to formation of antigen-antibody complexes occurs in ________.

• delayed hypersensitivity

• All of the choices are correct.

• anaphylaxis

• serum sickness

• hemolytic disease of the newborn

• serum sickness

The phase of the bacterial growth curve in which the rate of cell division equals the rate of cell death is the _____.

• death phase

• lag phase

• telophase

• log phase

• stationary phase

• stationary phase

Helicase ________.

• winds RNA

• unwinds RNA

• supercoils DNA

• unzips DNA

• None of the choices are correct.

• unzips DNA

Substances that are naturally produced by certain microorganisms that can inhibit or destroy other microorganisms are called ________.

• narrow-spectrum drugs

• antibiotics

• synthetic drugs

• semisynthetic drugs

• antibiotics

Agar is an important component of media because ________.

• agar inhibits mold growth

• bacteria require agar to grow

• All of the choices are correct.

• agar provides a solid surface for bacterial growth

• agar prevents contamination

• agar provides a solid surface for bacterial growth

All of the following are characteristics of IgM except ________.

• is a dimer

• is the first class synthesized by a plasma cell

• can serve as a B-cell receptor

• contains a central J chain

• has 10 antigen binding sites

• is a dimer

Drug susceptibility testing determines _______.

• if the drug is increasing to toxic levels in a patient

• the pathogen's response to various antimicrobials

• the patient's response to various antimicrobials

• if normal flora will be affected by antimicrobials

• None of the choices are correct.

• the pathogen's response to various antimicrobials

Antimicrobial agents can target the cell wall by ________.

• digesting it

• inhibiting peptidoglycan synthesis

• All of the choices are correct

• blocking its synthesis

• All of the choices are correct

Which enzyme is responsible for unzipping of the DNA double strand?

Transaminase

DNA Polymerase

Helicase

Ligase

Helicase

Which of the following is not true regarding glycolysis?

• It occurs without oxygen

• It involves the reduction of NAD ⁺

• It degrades glucose to CO ₂ and H ₂O

• It ends with the formation of pyruvic acid

• It occurs during fermentation

• t degrades glucose to CO ₂ and H ₂O

An organelle that is a stack of flattened, membranous sacs and functions to receive, modify, and package proteins for cell secretion is the ________.

• endoplasmic reticulum

• Golgi apparatus

• lysosome

• mitochondria

• chloroplast

• Golgi apparatus

A holoenzyme is a combination of a protein and one or more substances called _____.

• reactants

• substrates

• catalysts

• cofactors

• apoenzymes

• cofactors

Which type of microscope bombards a whole, metal-coated specimen with electrons moving back and forth over it?

• Scanning electron

• Transmission electron

• Phase contrast

• Fluorescence

• Differential interference contrast

• Scanning electron

Each ________ is a specific segment of the DNA with the code for production of one functional product.

• intron

• gene

• operator

• exon

•  triplet

• gene

A three base sequence on mRNA is called a(n) ________.

• anticodon

• intron

• exon.

• codon

• codon

Disease-causing microorganisms are called _____.

• fermenters

• prokaryotes

• pathogens

• decomposers

• eukaryotes

• pathogens

All bacterial cells have ________.

• capsules

• one or more fimbriae

• the ability to produce endospores

• flagella

• one or more chromosomes

• one or more chromosomes

In eukaryotic cells, ribosomes have two locations: scattered in the ________ and on the surface of the _________.

• cytoplasm; endoplasmic reticulum

• cytoplasm; Golgi apparatus

• nucleus; endoplasmic reticulum

• nucleus; Golgi apparatus

cytoplasm; endoplasmic reticulum

Plasma cells ________.

• suppress immune reactions

• secrete antibodies

• directly destroy target cells

• activate B cells and other T cells

• function in allergic reactions

• secrete antibodies

Immunologic methods of identifying microorganisms in a patient sample are characterized as those that ________.

• rely on the specificity of antibodies to target a single antigen

• amplifies the microbial DNA in the patient's sample and during the process, identifies the organism through the use of known primers

• analyze the genetic makeup of the microorganism, which conclusively diagnoses the infection

• directly examine the organism's appearance or behavior,which includes its metabolic abilities, environmental preferences and drug susceptibilities

• rely on the specificity of antibodies to target a single antigen

All of the following pertain to transcription except ________.

• requires a template DNA strand

• requires RNA polymerase

• occurs before translation

• occurs on a ribosome in the cytoplasm

• proceeds in the 5' to 3' direction of the growing mRNA molecule

• occurs on a ribosome in the cytoplasm

________ carriers are shedding and transmitting pathogens a long time after they have recovered from an infectious disease.

• Passive

• Incubation

• Chronic

• Convalescent

• Asymptomatic

• Chronic

The term autotroph refers to an organism that ________.

• uses CO ₂ for its carbon source

• gets energy by oxidizing chemical compounds

• does not need a carbon source

• must obtain organic compounds for its carbon needs

• gets energy from sunlight

• uses CO ₂ for its carbon source

All of the following pertain to nitrogenous bases except________.

• guanine pairs with uracil

• adenine pairs with thymine

• cytosine and thymine are pyrimidines

• form pairs by hydrogen bonding

• they are only present in the form of purines

• guanine pairs with uracil

Lymphocytes ________.

• have membrane receptors that recognize foreign antigens

• All of the choices are correct.

• develop into clones of B and T cells with extreme variations of specificity

• gain tolerance to self by destruction of lymphocytes that could react against self

• possess MHC antigens for recognizing self

• All of the choices are correct.

Organisms were classified into kingdoms as they were defined. Which list reflects the order of discovery of the kingdoms as we know them today?

• Plants and animals, protista, monera, fungi

• Monera, plants and animals, protista, fungi

• Protista, fungi, monera, plants and animals,

• Fungi, monera, plants and animals, protista

• Monera, protista, fungi, plants and animals

• Plants and animals, protista, monera, fungi

he cell's metabolic reactions involve the participation of ________ that lower the activation energy needed for the initiation of a reaction.

• cofactors

• enzymes

• ATP

• vitamins

• enzymes

Physical agents for controlling microbial growth include all the following except _____.

• hydrogen peroxide

• boiling water

• ultraviolet radiation

• HEPA filters

• pasteurization

• hydrogen peroxide

Which is not true about enzymes?

• They are found in all cells.

• They have high-energy bonds between phosphates.

• They can be denaturated by heat and other agents.

• Their shape determines their function.

• They are catalysts.

• They have high-energy bonds between phosphates.

The phase of the bacterial growth curve that shows the maximum rate of cell division is the _____.

• stationary phase

• exponential (log) phase

• death phase

• lag phase

• prophase

• exponential (log) phase

The circulating substances that affect the hypothalamus and initiate fever are ________.

• pyrogens

• lysozymes

• interferons

• complement

• leukotrines

• pyrogens

Which order below reflects the correct procedure for Gram staining?

• Crystal violet–alcohol/acetone–iodine–safranin

• Crystal violet–iodine–alcohol/acetone–safranin

• Iodine–safranin–crystal violet–alcohol/acetone

• Alcohol/acetone–safranin–crystal violet–iodine

• Alcohol/acetone–crystal violet–safranin–iodine

• Crystal violet–iodine–alcohol/acetone–safranin

Which white blood cells comprise 20% to 30% of the circulating WBCs and are the cells that function in the body's third line of defense?

• Basophils

• Monocytes

• Eosinophils

• Lymphocytes

• Neutrophils

• Lymphocytes

An apoenzyme is ________.

• also called a coenzyme

• an RNA molecule

• the protein part of a holoenzyme

• often an inorganic metal ion

• part of a simple enzyme

• the protein part of a holoenzyme

Lysozyme is found in ________.

• sweat from sweat glands

• mucous membranes of the gastrointestinal tract

• salivary secretions

• All of the choices are correct.

• mucous membranes of the respiratory tract

• salivary secretions

All infectious diseases ________.

involve viruses as the pathogen

occur only in humans

are caused by vectors

are caused by microorganisms or their products

are contagious

are caused by microorganisms or their products

Ketoconazole, fluconazole, clotrimazole, miconazole are broad-spectrum azoles used to treat ________ infections.

• protozoan

• helminthic

• bacterial

• fungal

• fungal

Neutrophils, eosinophils, and basophils are called _______ because they have prominent cytoplasmic inclusions that, in a stained blood smear, appear with identifying, characteristic colors.

• agranulocytes

• leukocytes

• granulocytes

• monocytes

• None of the choices are correct.

• granulocytes

Carl Woese and George Fox developed the three-domain system of taxonomy based on what molecular discovery?

• Variations in the ribonucleic acid of the small ribosomal subunit of organisms

• Molecular analysis of genes showing that eukaryotes evolved from bacteria, and bacteria evolved from archaea

• Genetic analysis showing that bacteria and archaea are identical

• Mutations in enzyme proteins

• Variations in the ribonucleic acid of the small ribosomal subunit of organisms

What type of isolation technique is most effective for the majority of applications?

• Pour plate

• Culture plate

• Streak plate

• Spread plate

• Loop dilution

Streak plate

The granules of basophils contain ________.

• antigens

• histamine

• antibodies

• digestive enzymes

• lysozyme

• histamine

A pure culture contains ________.

• None of the choices are correct.

• only one species of microorganism

• only bacteria

• a variety of species from the same genus

• a variety of microbes from one source

• only one species of microorganism

The duplication of a cell's DNA is called ________.

• transcription

• mitosis

• mutation

• translation

• replication

• replication

The Gram staining procedure is best described as a(n) _______ staining technique.

• acid-fast or Ziehl-Neelson

• simple

• flagellar

• differential

• capsule

• differential

Which of the features listed below is not found in all cells?

• Ribosomes

• DNA

• Nucleus

• Cytoplasmic membrane

• Nucleus

Autoimmunity is typically due to ________.

• graft rejection

• a transfusion reaction

• IgE and mast cells

• autoantibodies and T cells

• a deficiency in T-cell development

• autoantibodies and T cells

Base pairs in DNA are held together by _____ bonds.

• peptide

• polar covalent

• hydrogen

• sulfhydryl

• nonpolar covalent

• hydrogen

Diffusion of water through a semipermeable membrane is called _____.

• facilitated diffusion

• diffusion

• endocytosis

• active transport

• osmosis

• osmosis

Which of the following does not reflect anabolism?

• Fatty acid assimilation to form lipids.

• DNA replication from nucleotides.

• Beta oxidation of fatty acids to acetyl CoA.

• Enzyme production from amino acids.

• Beta oxidation of fatty acids to acetyl CoA.

Which of the following statements best describes the initiation of translation?

• The mRNA containing the start codon, AUG, sits at the P site and forms a complex with the corresponding tRNA, and the large and small ribosomal subunits.

• The mRNA attaches to the large ribosomal subunit and once the start codon reaches the A site, the tRNA binds and the small subunit completes the complex.

• A tRNA with the anticodon, AUG, enters the ribosomal complex and binds to the mRNA at the A site.

• The large and small ribosomal subunits scan the mRNA in the 3'–5' direction until the promoter is reached.

• The mRNA containing the start codon, AUG, sits at the P site and forms a complex with the corresponding tRNA, and the large and small ribosomal subunits.

A permanent, inheritable change in the genetic information is called ________.

• regeneration

•  alteration

• translation

• mutation

•  transcription

• mutation

Peptidoglycan is a unique macromolecule found in bacterial _____.

• slime layers

• cell walls

• cell membranes

• inclusions

• capsules

• cell walls

Which term is not used to describe bacterial cell shapes?

• Tetrad

• Rod

• Spirochete

• Vibrio

• Coccus

• Tetrad

The size of a eukaryotic cell ribosome is ________.

• 70S

• 50S

• 30S

• 80S

• 80S

Plasmids ________.

• are essential for growth and metabolism

• cannot be passed between organisms

• are found in all bacteria

• cannot be passed on to progeny

• are often the site of pathogenic genes

• are often the site of pathogenic genes

A properly functioning immune system is responsible for ________.

• Only recognition of foreign materialand destruction of foreign materialare correct.

• All of the choices are correct.

• recognition of foreign material

• surveillance of the body

• destruction of foreign material

• All of the choices are correct.

During replication, each parent DNA strand serves as a _______ for synthesis of new DNA strands.

• copy point

• reservoir

• scaffold

• comparison molecule

• template

• template

Reactants are converted to products by ________.

• reactants releasing energy

• breaking and forming bonds

• enzymes releasing energy

• enzymes binding to reactants

• None of the choices are correct

• breaking and forming bonds

Histamine, serotonin, and bradykinin are all ________.

• mediators of T-cell activity

• vasoactive mediators

• fever inducers

• mediators that increase chemotaxis

• mediators of B-cell activity

• vasoactive mediators

An organelle that is a stack of flattened, membranous sacs and functions to receive, modify, and package proteins for cell secretion is the ________.

• mitochondria

• Golgi apparatus

• lysosome

• chloroplast

• Golgi apparatus

Which of the following is essential for development of discrete, isolated colonies?

• Assay medium

• Differential medium

• Broth medium

• Solid medium

• Selective medium

• Solid medium

Cells, like bacteria and archaea, that do not have a nucleus in their cells have traditionally been called ________.

• pathogens

• eukaryotes

• prokaryotes

• decomposers

• prokaryotes

Microorganisms require small quantities of _____ for enzyme function and maintenance of protein structure.

• trace elements

• water

• carbon

• growth factors

• macronutrients

• trace elements

Infections that go unnoticed because there are no symptoms are called ________.

• malaises

•  syndromes

• asymptomatic

• inflammation

• asymptomatic

Components of the first line of defense include all the following except ________.

• phagocytic white blood cells

• the tough cell sheet of the upper epidermis of the skin

• nasal hairs

• flushing action of tears and blinking

• flushing action of urine

• phagocytic white blood cells

Enzymes are ________.

• not needed for catabolic reactions

• proteins that function as catalysts

• All of the choices are correct

• used up in chemical reactions

• broken down in reactions that require energy input

• proteins that function as catalysts

Which of the following is incorrect about inflammation?

• Fever could be beneficial to inhibiting the pathogen.

• Basophils and mast cells release histamine.

• It can last hours to years.

• Serotonin causes smooth muscle contraction.

• Pyrogens cause vasodilation and increased capillary permeability.

• Pyrogens cause vasodilation and increased capillary permeability