Microbio Midterm Review

Iron-binding proteins are examples of virulence factors that permit ___________. nutrient acquisition invasion of host tissues immune system evasion adhesion to host tissues

nutrient acquisition

Organisms that have an absolute dependence on abundant oxygen for cellular processes are __________. obligate anaerobes obligate aerobes microaerophiles facultative anaerobes

obligate aerobes

Of the following, which would be considered a biochemical test? observing a change in pH after the breakdown of a substrate observing the colony formation on a plate observing the cell's shape and arrangement under a microscope observing its motility while growing in motility agar

observing a change in pH after the breakdown of a substrate

Early symptoms develop during the __________ of infectious disease. acute phase incubation period prodromal phase convalescent phase

prodromal phase

Listeria monocytogenes grows best at refrigerator temperatures and is therefore considered a _________. psychrotroph mesophile psychrophile thermophile

psychrotroph

In an evolutionary sense, a "successful" pathogen is one that: is minimally symptomatic. rapidly debilitates a host. is highly toxic. rapidly kills a host.

rapidly kills a host

Tuberculosis is an example of a(n) __________ disease. emerging endemic sporadic reemerging

reemerging

The animate or inanimate habitat where an infectious agent is usually found is the _________. vector source reservoir host

reservoir

RNA nucleotides are made of a sugar, a phosphate, and a nitrogen base. Which sugar is unique to RNA nucleotides and NOT found in DNA nucleotides? glucose ribose deoxyribose fructose

ribose

During the __________ phase of bacterial growth in a closed system, the number of cells dying equals the number of cells dividing. stationary log death lag

stationary phase

The term used by molecular biologists to describe the flow of genetic information from DNA, to RNA, to protein is __________. the central dogma of biology translation gene expression transcription

the central dogma of biology

Choose the true statement about Gram-negative versus Gram-positive cells Gram-negative cells are better able to survive in a dry environment than Gram-positive cells. Gram-negative cells have teichoic acids while Gram-positive cells do not. Gram-negative cells are more resistant to penicillin-based drugs than Gram-positive cells Gram-negative cells are more resistant to mechanical stress than Gram-positive cells

Gram-negative cells are more resistant to penicillin-based drugs than Gram-positive cells

What is the average net gain of ATP produced in fermentation? 4 to 5 ATP molecules 5 to 6 ATP molecules 1 to 2 ATP molecules 3 to 4 ATP molecules

1 to 2 ATP molecules

The experiments that finally disproved spontaneous generation were performed by: Francesco Redi Antonie van Leeuwenhoek Louis Pasteur Robert Koch

Louis Pasteur

Which of the following is a description of a symbiotic relationship in which the symbiont is helpful to the host? Mutualism Commensalism Antagonism Parasitism

Mutualism

Choose the true statement about phototrophs. Phototrophs do not include autotrophs. They break down nutrients for energy. Phototrophs include human cells. Phototrophs use light for energy.

Phototrophs use light for energy.

Which of the following is not a characteristic of archaeal plasma membranes? They can form monolayer membranes They are made of linear fatty acids The fatty acids are joined to glycerol by an ether bond They are made of long-branched fatty acids

They can form monolayer membranes

Which of the following types of toxins damage cells by binding to host cell receptors? Endotoxins Type II exotoxins Type I exotoxins Type III exotoxin

Type 1 exotoxins

An essential amino acid is __________. an amino acid the cell must make, or it will die an amino acid it can make using a pathway an amino acid that has been deaminated an amino acid the cell cannot make and must obtain from the environment

an amino acid the cell cannot make and must obtain from the environment

Yearly vaccinations for influenza are necessary due to __________. antigenic drift viral attenuation antigenic shift mutations to reverse transcriptase

antigenic drift

Which of the following suggests mitochondria evolved from prokaryotic ancestors? 70S ribosomes Circular DNA Cristae Matrix

70S ribosomes

Which of the following is an example of catabolic and anabolic reactions working together? A cell transports a disaccharide across the plasma membrane against the concentration gradient. A cell breaks down glucose into two pyruvic acid molecules, which are then converted into acetyl-CoA and then broken down further in the Krebs cycle. A cell breaks down a polysaccharide to produce ATP, which is then used to build a polypeptide molecule. A cell uses an enzyme to speed up the reaction of adding phospholipids to the cellular plasma membrane.

A cell breaks down a polysaccharide to produce ATP, which is then used to build a polypeptide molecule.

Which of the following methods uses steam-heat and pressure to effectively sterilize microbiological media and equipment? Dry heating Autoclaving Boiling Pasteurization

Autoclaving

Which of the following best describes how bacterial growth in nature is different from growth in a laboratory setting? Bacteria tend to grow as single species in nature. Bacteria have nutrients in the lab setting, but not in nature. Most bacteria that grow in nature can also be readily grown in the lab. Bacteria tend to grow as a mixture of species in biofilms in nature

Bacteria tend to grow as a mixture of species in biofilms in nature.

Of the following, which does NOT occur in the Krebs cycle? CO2 molecules are removed through a process called decarboxylation. Carbon molecules are reduced and the electron carrier molecules are oxidized. Acetyl-CoA reacts with oxaloacetic acid to form citric acid. Electron carrier molecules, such as NAD+ and FAD+, are reduced.

Carbon molecules are reduced and the electron carrier molecules are oxidized.

Choose the false statement about enzymes. Enzyme activity can be affected by temperature and pH changes Enzymes are proteins Enzymes are only needed in small quantities Enzymes are used up in a reaction

Enzymes are used up in a reaction

Each of the following describes eukaryotic cilia except: Found in both prokaryotes and eukaryotes. Surrounded by a membrane. Sweeping mucus in the upper airway. Produce a synchronized rowing motion.

Found in both prokaryotes and eukaryotes.

The core component of __________ cell walls is chitin. Plant Protista Prokaryotic Fungal

Fungal

Group B Streptococcus (GBS) is considered a commensal organism in women, yet babies are susceptible to infection with GBS. All of the following are reasons why this occurs except: babies do not have a fully established microbiota to compete with GBS and are more susceptible to infection. babies' immune systems are not fully developed and cannot overcome infection with GBS. GBS doesn't encounter the same host factors in the baby as it does in the mother. GBS doesn't produce the same virulence factors in the baby as it does in in the mother.

GBS doesn't produce the same virulence factors in the baby as it does in in the mother.

Which of the following is a carbohydrate substance that encourages bacterial adhesion to host tissues? Pili Flagella Fimbriae Glycocalyx

Glycocalyx

Choose the true statement about a bacterial colony? Colony isolation requires concentrating a specimen. A pure culture would generate colonies with diverse features. Colonies can be grown using broth media. In theory a colony derives from a single cell.

In theory a colony derives from a single cell.

Choose the false statement about binary fission. It is a form of asexual cell division. Chromosome replication occurs early in the process. It produces daughter cells that are genetically unique from one another. Prokaryotic cells perform it.

It produces daughter cells that are genetically unique from one another.

Choose the single true statement about equilibrium. The amount of product(s) and reactant(s) is equal. Products and reactants form at an equal rate. The reaction stops at equilibrium. The total amount of products and reactants is changing.

Products and reactants form at an equal rate

Which of the following molecules is a defining characteristic of a ribozyme? RNA cofactors DNA coenzymes

RNA

Why are biochemical tests referred to as "fingerprint methods of bacterial species"? They are used to determine its cell shape and cell wall type. They are used to identify bacterial species. They are used to determine the natural habitat of the organism. They are used to determine the bacterial species' sensitivity to antimicrobial agents.

They are used to identify bacterial species.

Which of the following is not a reason that acid-fast bacteria are clinically a challenge? They grow slowly These are all clinical concerns about acid-fast bacteria They have a waxy layer that limits drug entry They form endospores that resist heat and sanitizing practices

They form endospores that resist heat and sanitizing practices

__________ pathogens are always capable of causing disease in a host, regardless of their health status. True Bacterial Opportunistic Viral

True

__________ contain mainly water and other substances and are mainly found in plants, fungi, and certain prokaryotes and protists. Peroxisomes Lysosomes Vacuoles Secretory vesicles

Vacuoles

Tropism is best described as: a pathogen's preference for a specific host. a microbe that causes infection in a weakened host. disruption of normal microbiota. an interaction that benefits both host and microbe.

a pathogen's preference for a specific host.

If a patient is asymptomatic for long periods of time but has symptoms reemerge, they are in a __________ state. convalescent chronic carrier prodromal asymptomatic carrier

chronic carrier

The common cold is a good example of a __________ disease. non-communicable communicable sporadic epidemic

communicable

Enzyme specificity allows for __________. randomized cellular processes unregulated cellular processes undefined cellular processes controlled cellular processes

controlled cellular processes

Respiratory pathogens cause symptoms of _________ that make it more likely that it will be transmitted to other hosts. copious diarrhea pus or drainage coughing and sneezing itchy, watery eyes

coughing and sneezing

Viral genetic reassortment is most likely to occur when __________. random mutations occur RNA viruses fail to proofread during RNA replication an attenuated strain emerges different viral strains infect the same cell

different viral strains infect the same cell

Researchers attempting to determine the effect of a treatment for disease are engaged in _________ studies cross-sectional observational experimental correlation

experimental

Septic shock is characterized by: contractile paralysis. explosive, watery diarrhea. gas gangrene. hypotension, tachycardia, and organ failure.

hypotension, tachycardia, and organ failure.

In eukaryotic mRNA, there are sequences of mRNA that do NOT encode for specific amino acids and do NOT contribute to the protein. These sequences are called __________. Okazaki fragments introns exons promoters

introns

A __________ is a single particle made up of genetic material encased in a protein shell. capsomere virion spike capsid

virion

Proteins provide cells with the necessary equipment to perform normal cellular activity. Without gene expression the cell __________. could function with minimal capabilities would die would still be able to metabolize substrates would still be able to reproduce

would die

Retroviruses produce mRNA by: DNA (dsDNA) and then using the dsDNA for transcription. translating the viral RNA genome as mRNA. unwinding double-stranded RNA (dsRNA) and then transcribing it into an mRNA format. using reverse transcriptase to convert single- stranded RNA (ssRNA) to double-stranded using virally encoded RNA-dependent RNA polymerases to build a new RNA from an existing RNA template.

x