Cumilative microbiology 1

The best definition of endosymbiosis is ______.

A DNA virus, a bacteria and a photosynthetic prokaryote fused to form a nucleus, a chloroplast and a mitochondria

Spirochetes are able to move due to ________.

A periplasmic flagellum

Rubella is ________.

All of the choices are correct.

Fifth disease ________.

All of the choices are correct. has a maculopapular rash that lasts for days to weeks cannot be prevented at this time with vaccination is caused by Parvovirus B19 is a childhood febrile disease with a bright red rash on the cheeks

Chickenpox ________.

All of the choices are correct. lesion distribution is centripetal has an incubation of 10 to 20 days is transmitted by droplet contact has a fever and vesicular rash that occurs in successive crops

Microbial resistance resulting from mutation occurs because ________.

All of the choices are correct: mutations are passed between organisms bacterial genomes undergo mutation rapidly short generation times accumulate mutations in populations bacterial genomes undergo mutation often

Reverse transcriptase synthesizes ________.

DNA from RNA

An ideal antiviral drug would be one that killed the host cell, effectively preventing the virus from replicating.

False

The acceptance or rejection of a hypothesis is based on a series of educated guesses and opinions. Once the opinion is widely accepted it becomes a theory.

False

Which statement below supports the argument that gram-negative cells are structurally diiferent than gram-positive cells?

Gram-negative cells have a thinner layer of peptidoglycan in their cell wall compared to gram-positive cells.

Which of the following does not pertain to endotoxin?

It is found in acid-fast bacterial cell walls

The surgeon who advocated using disinfectants on hands and in the air prior to surgery was ________.

Joseph Lister

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

Mycobacterium

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

Nucleus Cytoplasmic membrane DNA Ribosomes

Which of the following is not true regarding the structure and function of viral spikes?

They are coded for by the host genome

Viruses are simple, noncellular, and lack ribosomes.

True

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

A superinfection results from ________.

a decrease in most normal biota resulting in the overgrowth of an unaffected species.

If an infectious disease emerged that was highly contagious and virulent, resulting in certain death with no known cure, epidemiological data would show

a low incidence and high prevalence.

HEPA filters are used to remove microbes from ________.

air

The term that refers to flagella at both poles is ________.

amphitrichous

The antifungal drug that can be injected to treat serious systemic fungal infections, like histoplasmosis, is ________.

amphotericin B

The betadine swab before blood donation is an example of ________.

antisepsis

Protozoan cysts ________.

are helpful in surviving unfavorable conditions.

All microorganisms are best defined as organisms that ________.

are too small to be seen with the unaided eye

A(n) ________ is the protein shell around the nucleic acid core of a virus.

capsid

Staphylococcus can be differentiated from Streptococcus by the ________.

catalase test

Creutzfeldt-Jakob disease is ________.

caused by a latent disease

During unfavorable growth conditions, many protozoa can convert to a resistant, dormant stage called a(n) ________.

cyst

Selective toxicity refers to ________.

damage to the target organisms but not host cells

Removal of moisture by dehydration is called ________.

desiccation

In humans, helminths generally infect the ________.

digestive tract

Fungi that grow as yeast at one temperature but will grow as mold at another temperature are called ________.

dimorphic

Surfactants work by ________.

disrupting membrane integrity

All of the following pertain to measles (rubeola) except ________.

dry cough, sore throat, fever, and conjunctivitis are symptoms it is transmitted by direct contact with the rash humans are the only reservoir for the pathogen it involves a fatal complication called subacute sclerosing panencephalitis (SSPE) secondary bacterial otitis media and sinusitis can occur

The study of the frequency and distribution of a disease in a defined population is ________.

epidemiology

Each of the following affect cell walls except ________.

erythromocin

The toxin of Staphylococcus aureus strains that causes blisters and desquamation of skin in scalded skin syndrome is ________.

exfoliative toxin

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

false

Cellular organisms without a true nucleus include bacteria and viruses.

false

Each bacterial species represents a distinct organism that can produce viable offspring when mating with other bacteria of its kind.

false

Gram-negative bacteria do not have peptidoglycan in their cell walls.

false

Iodine is the decolorizer in the Gram stain.

false

The gram-positive cell wall is considered stronger than that of gram-negative cells since its hydrophobic outer membrane contains an endotoxin.

false

The greatest hurdle to overcome when treating biofilm infections is finding a drug that can penetrate the extracellular material.

false

Amoebiasis (amoebic dysentery) is most commonly contracted through the ________.

fecal-oral route from contaminated food or water

Fungal spores differ from bacterial endospores in that ________.

fungal spores are reproductive, whereas bacterial endospores are for survival

Lipopolysaccharide is an important cell wall component of ________.

gram-negative bacteria

Mebendazole is a drug used to treat ________ infections.

helminthic

Penicillinases are enzymes produced by bacterial cells, usually after acquiring a new gene, that ________.

hydrolyze the β-lactam ring of penicillins and cephalosporins, rendering them ineffective

The advantage of using ethylene oxide as a sterilant over moist heat sterilization in an autoclave is that ________.

it can be used to sterilize plastics that would melt in an autoclave

Which of the following is a unique characteristic of viruses that distinguishes them from the other major groups of microorganisms?

lacks cell structure

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

lophotrichous

The group of protozoa that have flagella are the ________.

mastigophora

The drug used for several protozoan infections is ________.

metronidazole

The effect of "good" microbes against invading microbes is called ________.

microbial antagonism

Which of the following is not considered a microorganism?

mosquito

A naked virus has only a(n) ________.

nucleocapsid

In general, most DNA viruses multiply in the host cell's ________, while most RNA viruses multiply in the host cell's ________.

nucleus; cytoplasm

Transmission of tineas includes ________.

oil to human fomites to human animal to human human to human

Mammalian viruses capable of starting tumors are ________.

oncoviruses

Biofilm infections are harder to treat than the same free-living organisms because ________.

organisms in a biofilm develop antibiotic resistance more rapidly than free-living cells

Helminths are ________.

parasitic worms

Microbial death occurs when there is ________.

permanent loss of reproduction

The lipid group that is the major component of cell membranes is the ________.

phospholipids

Which is not a characteristic of fungi?

photosynthetic

Nutrients that encourage the growth of beneficial microbes in the intestines are known as ________.

prebiotics

Two noncellular agents, smaller than viruses, are the infectious proteins called ________ and the infectious RNA strands called ________.

prions; viroids

Exotoxins are ________.

proteins

Histones are ________.

proteins associated with DNA in the nucleus

Cell walls are not usually found in ________.

protozoa

Viruses acquire envelopes around their nucleocapsids during ________.

release

The most prevalent worldwide infectious diseases are ________.

respiratory disease

Blisters ________.

result from a separation of epidermis from dermis.

Measles is also known as ________.

rubeola

Streptococcus pyogenes causes all of the following except ________.

scalded skin syndrome

The method of removing vegetative microbial life forms from inanimate objects is termed ________.

sepsis

Sterilization is achieved by

steam autoclave

A chain of rod-shaped cells would be called a(an) ________.

streptobacillus

Broad-spectrum drugs that disrupt the body's microbiota often cause ________.

superinfections

An example of an antibacterial drug with high selective toxicity would be one that ________.

targets the synthesis of the bacterial cell wall

A ratio of the dose of a drug that is toxic to humans versus the minimum effective dose for that pathogen is assessed to predict the potential for toxic drug reactions. This is called the ________.

therapeutic index (TI)

Semisynthetic penicillins have an advantage over their naturally occurring counterparts in that ________.

they have a broader target range and are less susceptible to penicillinases

Enterotoxins are

toxins that target the intestines

The motile, feeding stage of protozoa is called the ________.

trophozoite

A fully formed virus that can cause an infection in a host cell is called a virion.

true

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

true

Despite the lack of a membrane-bound nucleus, bacteria and archaea are cells with a complex organizational structure.

true

Fungi can reproduce both sexually and asexually.

true

Infections caused by fungi are called mycoses.

true

Latency is a dormant state of an infectious agent.

true

One distinguishing characteristic of the archaebacteria is that they live in extreme environments.

true

Phenols are useful antimicrobial compounds in that they are effective against bacteria fungi and viruses, disrupting several cellular targets, however, they have been removed from many consumer products because of their high toxicity and propensity to select for resistant strains of microorganisms.

true

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

true

Virulence differs from pathogenicity in that pathogenicity describes the ability of an organism to cause disease, whereas virulence describes the degree of pathogenicity as the disease develops.

true

Viruses are unable to multiply outside of a host cell.

true

Pathogenic microbes that cause disease in healthy people are called ________.

true pathogens

A method for sterilizing milk, called ________ treatment, uses 134°C for 1 to 2 seconds.

ultra high temperature

The easiest microbial forms to kill or inhibit are ________.

vegetative bacteria and fungi

Which group of microorganisms is composed only of hereditary material wrapped in a protein covering?

viruses