Microbiology Lecture - Test 1 (Ch. 1,3,4)

Lipid ___ is a part of the Gram-negative cell wall that can produce fever, inflammation, and shock when it is released into the bloodstream. A D K O

A

Viruses are unlike other infection agents studied by microbiologists in that they are ______. Obligate intracellular pathogens Acellular Extremely deadly All of the above

Acellular

What would you expect to see if you forgot to perform step 2 of the Gram stain procedure? Hint: Function of mordants. Gram-positive cells would appear purple and Gram-negative cells would appear pink. Gram-positive cells would appear pink and Gram-negative cells would appear purple. All bacteria would appear pink . All bacteria would appear purple.

All bacteria would appear pink.

What would you anticipate seeing if you accidentally switched crystal violet and safranin while performing a Gram stain? Hint: Safranin is relatively unaffected by mordants. Gram-positive bacteria would appear pink and Gram-negative bacteria would appear purple. All bacteria would appear purple. Gram-positive bacteria would appear purple and Gram-negative bacteria would appear pink. All bacteria would appear pink.

All bacteria would appear purple.

If a microbiologist omitted the decolorizer from a Gram stained smear, which of the following would happen? Hint: The decolorizing step is what allows the Gram stain to distinguish Gram-positive cellsfrom Gram-negative cells. All cells in the smear would be purple. All cells in the smear would be colorless. All cells in the smear would be pink. Gram-positive cells would be pink and Gram-negative cells would be purple.

All cells in the smear would be purple

What characteristic is shared by both molds and parasitic worms? Hint: Molds are multicellular eukaryotes that can be infectious They are eukaryotic They are studied by microbiologists They are multicellular All of the above are true

All of the above are true

Why is a specimen smaller than 200 nm not visible with a light microscope? The lenses only go to 100 X magnification power. It is too easy to lose on the stage. Anything smaller than 200 nm cannot interact with visible light. Visible light is only good at wavelengths below 390 nm.

Anything smaller than 200 nm cannot interact with visible light

Martin is a nurse who contracted a disease while acting as a volunteer nurse in Zambia. The organisms infecting Martin are unicellular and do not have a nucleus. They are extremely small but can be seen with a light microscope when stained. Which of the following categories of microorganisms would they be classified in? Protozoa Fungi Bacteria Algae

Bacteria

Althouqh Gram staining is helpful in narrowing down the general type of bacteria causing the infection, it does not provide specific classification and identification of the bacteria. Why? Because Gram stains are simple stains providing no bacterial identification information. Because the Gram stain does not indicate the special staining structures that do provide definitive identification such as flagella stains or capsule stains. Because Gram staining does not differentiate or provide any useful information to identify bacteria. Because the Gram stain differentiates between Gram-negative and Gram-positive cell walls but not the genus and species of the bacteria.

Because the Gram stain differentiates between Gram-negative and Gram-positive cell walls but not the genus and species of the bacteria.

The cell walls of ___ contain tetrapeptides. Gram-negative bacteria Archaea Gram-positive bacteria Both Gram-positive and Gram-negative bacteria All prokaryotes

Both Gram-positive and Gram-negative bacteria

Which of the following scientists showed that fermentation does not require living cells? Koch Gram Pasteur Buchner

Buchner

In a compound microscope, the lens that directs light through the specimen is the ___ lens. Ocular Objective Condenser

Condenser

Which of the following statements concerning osmosis is FALSE? Osmosis stops when the system reaches equilibrium. During osmosis, water crosses to the side of the membrane with a lower solute concentration. * Osmosis requires a selectively permeable membrane. Crenation results when cells are placed in a hypertonic solution. Cells placed in hypotonic solutions will gain water.

During osmosis, water crosses to the side of the membrane with a lower solute concentration.

Martin has cholera, a disease that played a key role in good public health hygiene standards. Snow's research into cholera outbreaks in London provided the foundation for what branches of Microbiology? Virology Immunology Chemotherapy Epidemiology

Epidemology

Which of the following is part of the endomembrane system? Hint: Function of the endomembrane system. mitochondria cytoskeleton flagellum ribosomes Golgi apparatus

Golgi apparatus

Which of the following prokaryotic cells contains an outer membrane? Gram-positive bacteria Gram-negative bacteria Both Gram-positive and Gram-negative bacteria Archaea All prokaryotes

Gram-negative bacteria

Porins are present in ___ bacteria because, in these organisms, molecules entering the cell must pass through an extra layer of ___. both Gram-negative and Gram-positive; membrane Gram-negative; peptidoglycan Gram-negative; membrane Gram-positive; membrane Gram-positive; peptidoglycan

Gram-negative; membrane

If a microbiology lab technician left the safranin out of the Gram stain procedure, what would be the result? Gram-positive cells would be purple, and Gram-negative cells would be colorless. All cells would be purple. Gram-positive cells would be colorless, and Gram-negative cells would be pink. Gram-positive cells would be pink, and Gram-negative cells would be purple. All cells would be pink.

Gram-positive cells would be purple, and Gram-negative cells would be colorless.

What was Leeuwenhoek's contribution to the science of microbiology? He did experiments supporting the idea of spontaneous generation He developed the first fairly high magnification microscope He discovered some of the ways in which microbes can be transmitted between individuals He developed the vaccine for smallpox

He developed the first fairly high magnification microscope

Modern biologists had to revise Linnaeus's system of taxonomy because ___. Hint: Linnaeus was a botanist who lived in the 18th century. He grouped all organisms into only two categories He did not know that some organisms reproduce asexually He only classified organisms found in Sweden He thought all organisms spontaneously generated

He grouped all organisms into only two catagories

A bacterial cell stains positive with the acid-fast stain. Which of the following is NOT true? Hint: The acid-fast stain is typically used to identify certain types of bacteria that have cell walls with unusual molecules. 1. It has a cell wall that contains endotoxin. 2. It will be difficult to stain this cell with the Gram stain. 3. It may be a member of the genus Mycobacterium. 4. It has a cell wall that contains waxy lipids.

It has a cell wall that contains endotoxin

Why does immersion oil improve resolution? It increases numerical aperture and maintains a uniform light speed. It decreases the working distance. It increases the angle of refraction of the light. It increases the numerical aperture. It allows light to travel at a uniform speed on its way to the lens.

It increases numerical aperture and maintains a uniform light speed.

How does the malachite green stain enter an endospore? It is dissolved in alcohol. It is mixed with the mordant tannic acid. It is mixed with hydrochloric acid. It is heated.

It is heated.

What is meant by light rays being divergent? It is heading upwards It is coming together to a focused beam It is spreading out

It is spreading out

A bacterial cell possesses a glycocalyx. Which of the following is NOT true? Hint: The glycocalyx is a gelatinous, sticky substance that surrounds many bacterial cells. It will be more pathogenic. It will be able to attach to surfaces. It will be less likely to dry out. It will be engulfed more quickly by defensive cells of the host.

It will be engulfed more quickly by defensive cells of the host

All of the following individuals showed that cleanliness played a role in human disease EXCEPT ___. Hint: One of these individuals was involved in the development of a vaccine against smallpox. Semmelweis Lister Nightingale Jenner

Jenner

Which of the following is an example of a dye used in a simple stain? Methylene blue Nigrosin Eosin

Methylene blue

A toxin made by certain strains of Vibrio cholera produces the serious gastrointestinal symptoms and water loss characterized by cholera. The study of that toxin, its biochemistry, and its effect on human cells would be called __________. Molecular biology Gene therapy Microbial genetics Recombinant DNA technology

Molecular biology

Which of the following molecules is shared by both Gram-positive and Gram-negative organisms? Hint: Cell wall structure. N-acetylmuramic acid lipopolysaccharide lipoteichoic acid lipid A

N-acetylmuramic acid

Nadia has a sore throat, fever, and a red rash on her face and neck. When a nurse practitioner looked into Nadia's throat, she saw white spots on the tonsils. A rapid streptococcal antigen test reveals that Nadia has strep throat. The white spots were white blood cells attempting to fight off the infection. Which of the following statements explains a key difference between Nadia's white blood cells and the Streptococcus pyogenes infecting her throat? The Streptococcus pyogenes have a cell membrane while Nadia's white blood cells do not. Nadia's white blood cells have a nucleus while the Streptococcus pyogenes do not. Nadia's white blood cells contain DNA while the Streptococcus pyogenes do not. The Streptococcus pyogenes do not contain ribosomes, while Nadia's white blood cells do contain ribosomes.

Nadia's white blood cells have a nucleus while the Streptococcus pyogenes do not

One of the ways smooth endoplasmic reticulum (ER) differs from rough endoplasmic reticulum is that rough ER is covered by ___. Hint: Function of rough ER. the extracellular matrix. the Golgi apparatus. mitochondria. the cytoskeleton. Ribosomes.

Ribosomes.

How is simple diffusion different from other types of passive transport? Simple diffusion requires ATP. Simple diffusion is only the diffusion of water. Simple diffusion only brings material into the cell, not out of it. Simple diffusion does not require a permease.

Simple diffusion does not require a permease

Which of the following statements about the endoplasmic reticulum (ER) is CORRECT? The rough ER is the site of lipid synthesis. The smooth ER is a site of ATP synthesis. The ER is a lipid storage organelle. The ER is a transport system within the cytoplasm. The smooth ER has ribosomes associated with it.

The ER is a transport system within the cytoplasm.

What will happen to a cell that is placed in a solution containing a high concentration of sugar, a molecule that cannot pass across the cell membrane? The cell will pump the salt in the cytoplasm out of the cell via simple diffusion. The cell will swell up with water and burst. The cell will lose its interior water, causing it to shrivel up and possibly die.

The cell will lose its interior water, causing it to shrivel up and possibly die.

Which of the following units of measure accurately compares epithelial cell size to bacterial size? The epithellal s,ells would look twice as large as the bacteria. The epithelial cells would look approximately the same size as the bacteria. The epithelial cells would look approximately 25-50 times larger than the bacteria. The epithelial cells would look about 10 times larger than the bacteria.

The epithelial cells would look approximately 25-50 times larger than the bacteria.

In a typical brightfield microscope, at which point does magnification begin? The condenser lens The ocular lens The objective lens The stage The lamp

The ocular lens

What happens to the light rays when they hit the specimen? They are reflected, refracted, or absorbed by the specimen. They are diverted to the ocular lens. They are absorbed by the stage. They are focused into a small area towards the objective lens.

They are reflected, refracted, or absorbed by the specimen.

Which of the following is a trait shared by both archaea and protozoa? They are prokaryotic They are animal-like They are unicellular They are obligate intracellular parasites

They are unicellular

The large cells in this micrograph are classified as eukaryotic cells because ________. They do not have a cell wall They are stained a particular color They are much larger than the other cells They have a nucleus

They have a nucleus

How are the bacteria and the archaea different from all the other cellular microbes? They reproduce asexually They have cell walls They have no nucleus They can move

They have no nucleus

How are negative stains different from other types of stains? They stain the background, leaving the cells colorless. They stain the desired structure or specimen black. They stain more than one type of specimen.

They stain the background, leaving the cells colorless.

What is the fundamental purpose of staining in light microscopy? To increase the contrast and visibility of the specimen To kill the specimen To make the specimen appear larger in the microscope To see the specimen without the aid of a microscope

To increase the contrast and visibility of the specimen

What is the role of the ocular lens? To recreate the image in the viewer's eye To adjust the wavelength of light To do the bulk of the magnification To focus the light to a high intensity in a small area

To recreate the image in the viewer's eye

The Gram stain can be used to distinguish bacteria based on the structure of their cell walls. True False

True

Following an endospore stain, how does one distinguish endospores from vegetative cells? Vegetative cells are pink, endospores are green. Vegetative cells are green, endospores are pink. Vegetative cells are purple, endospores are pink. Vegetative cells are pink, endospores are purple.

Vegetative cells are pink, endospores are green.

How is osmosis different from simple diffusion? Water requires a special permease. Water movement is driven by the concentration of solutes rather than its own concentration. Water requires energy to move across a cytoplasmic membrane. Water cannot pass freely across the membrane.

Water movement is driven by the concentration of solutes rather than its own concentration.

Koch's work involving anthrax was significant because it was the first time ___. anthrax had been discovered in humans a bacterium had been proven to cause a disease bacteria had been grown in a laboratory bacteria had been seen in a microscope

a bacterium had been proven to cause a disease

Which structural feature of Gram-positive bacteria enhances their ability to retain the crystal violet dye? an outer membrane a thin peptidoglycan layer a thick peptidoglycan layer All of the above contribute to a Gram-positive cell's ability to retain crystal violet.

a thick peptidoglycan layer

Put the following taxonomic groups in order, from broadest group to most specific group: a. phylum b. genus c. family d. order b,c,d,a c, b,d,a a,c,d, b a,d,c, b

a. phylum d. order c. family b. genus

A patient suffering from tuberculosis could be diagnosed by use of the ___ stain. acid-fast endospore Gram flagellar capsule

acid-fast

While staining a mixed culture of Gram-positive and Gram-negative bacteria, switching the order of steps 2 and 3 would result in ___. Hint: Mordants. a change in the Gram reaction; Gram-negative cells would appear purple while Gram-positive cells would appear pink. all bacteria appearing clear all bacteria appearing purple all bacteria appearing pink

all bacteria appearing pink

Nonspecific permeases ___. allow only water to cross the cytoplasmic membrane. are not used for passive transport. allow a variety of molecules to cross the cytoplasmic membrane. allow only one type of solute to pass through the membrane.

allow a variety of molecules to cross the cytoplasmic membrane.

Which of the following types of microscopes reveals the surface features of extremely small objects? Hint: This type of microscope uses a pointed probe that scans the surface of a specimen. an atomic force microscope a transmission electron microscope a fluorescent microscope a confocal microscope

an atomic force microscope

Amoxicillin is an antibiotic that inhibits the formation of peptide cross-links. Amoxicillin, therefore, would most likely inhibit the growth of ___. Hint: Cell wall structure. only Gram-negative organisms neither Gram-positive nor Gram-negative organisms both Gram-positive and Gram-negative organisms only Gram positive organisms

both Gram-positive and Gram-negative organisms

This micrograph came from the most common type of microscope, which is the ___. Hint: Notice that the background of this specimen is illuminated. dark-field microscope bright-field microscope phase-contrast microscope Nomarski microscope

bright-field microscope

The presence of a(n) ___ enables bacterial and plant cells to resist the effects of hypotonic solutions. cell membrane cell wall glycocalyx capsule

cell wall

Lung infections in cystic fibrosis patients are very critical. Diagnosis and treatment are initially based upon an immediate (STAT) sputum Gram stain. What type of microscope is typically used to examine Gram stains? compound light microscope electron microscopes (SEM orTEM) scanning tunneling microscopes (STM) phase microscopes

compound light microscope

The structural framework in a cell is the ___. Hint: Cell structure. endoplasmic reticulum (ER). extracellular matrix. plasma membrane. cytoskeleton. endomembrane system.

cytoskeleton.

Which of the following is NOT a function of the Streptococcus pyogenes cytoplasmic membrane? active transport diffusion endocytosis selective permeability

endocytosis

A resolution of 1 um would be better than a resolution of 0.5 um. True False

false

Gram staining of bacteria provides all the physical characterization necessary to identify bacterial species. True False

false

Peroxisomes contain enzymes used to digest nutrients that have been brought into the cell through phagocytosis. True False

false

The three domains proposed by Carl Woese are the Archaea, the Eukarya, and the Protista. True False

false

A microorganism has the following characteristics: eukaryotic, multicellular, has cell walls, and grows in long filaments. What is its general classification? Hint: Penicillium chrysogenum is an example of this kind of microorganism. bacterium protozoan parasitic worm fungus

fungus

Spallanzani's experiments concerning spontaneous generation were not universally accepted because ___. he did not give proper credit to Needham for his experiments he eliminated air from entering his flasks by sealing them he did not know which bacteria were growing in his flasks he did not heat his infusion flasks long enough

he eliminated air from entering his flasks by sealing them

A higher concentration of solutes corresponds to a ___ (higher/lower) concentration of water in a given solution. lower higher

lower

Which of the following organelles breaks down worn-out organelles? rough endoplasmic reticulum (ER) Golgi apparatus smooth endoplasmic reticulum (ER) lysosomes mitochondria

lysosomes

What carries instructions for making proteins from the nucleus into the cytoplasm? Hint: Nuclear messages. DNA Rough ER ribosomes mRNA ATP

mRNA

The most appropriate unit of measurement for intact archaea is: meters (m). nanometers (nm). centimeters (cm). millimeters (mm). micrometers (um).

micrometers (um).

Where in a cell is ATP made? mitochondria lysosomes ribosomes chloroplasts nucleus

mitochondria

A(n) ___ is a substance that binds to a dye and makes it less soluble. primary stain mordant decolorizer counter stain

mordant

Which of the following chemical substances contributes to the unique characteristics of acid-fast bacteria? mycolic acid endotoxin N-acetylglucosamine peptidoglycan lipoteichoic acid

mycolic acid

Where is the genetic information of the eukaryotic cell stored? nucleus Golgi apparatus lysosomes smooth endoplasmic reticulum (ER) rough endoplasmic reticulum (ER)

nucleus

The ability of a lens to gather light is referred to as its ___. magnification. refraction. contrast. numerical aperture. resolution.

numerical aperture.

What structure acts as a selective barrier, regulating the traffic of materials into and out of the cell? Hint: Structure location. cytoskeleton endomembrane system plasma membrane nuclear envelope extracellular matrix

plasma membrane

Staining is an important way to improve which of the following aspects of microscopy? Hint: Staining involves the use of dyes to create a difference in intensity between an object and its background. resolution and contrast magnification and resolution numerical aperture and contrast contrast and magnification

resolution and contrast

A staining procedure that uses a single basic dye is called a(n) ___ stain. Differential negative simple compound

simple

Where are lipids made in the cell? smooth endoplasmic reticulum (ER) Golgi apparatus mitochondria rough endoplasmic reticulum (ER) ribosomes

smooth endoplasmic reticulum (ER)

Bacteria of the genus Mycoplasma are distinguished from other bacterial cells by ___. the presence of mycolic acid in their cell walls. cell walls composed solely of amino acids. the absence of a cytoplasmic membrane. the absence of a cell wall. unique ribosomes.

the absence of a cell wall.

Streptococcus pyogenes has a Gram-positive cell wall. What distinguishes Gram-positive bacterial cell walls from Gram-negative bacteria cell walls? the presence of phospholipids the presence of teichoic acid the presence of peptidoglycan the presence of a cytoplasmic membrane

the presence of teichoic acid Teichoic acid is unique to Gram-positive organisms and anchors the peptidoglycan layer to the cell membrane.

The traditional definition of a species does not work very well for bacteria because ___. Hint: The Linnaean definition of a species is "a group of organisms that interbreed toproduce viable offspring." they do not have genetic material they do not always produce viable offspring they mostly reproduce asexually they do not have definable reproductive cycles

they mostly reproduce asexually

Formation of a biofilm may contribute to bacteria's ability to cause disease. True False

true

Which of the following is NOT a component of bacterial cell walls? tubulin peptidoglycan lipoteichoic acids mycolic acid tetrapeptide

tubulin

Which of the following-groups of scientists did NOT contribute to research in microbial genetics? Hint: One of these choices is a group of scientists known for their research on the role of microbes in the environment. Beadle and Tatum Winogradsky and Beijerinck Avery, Macleod, and McCarty Woese and Pauling

winogradsky and beijerinck

Who proposed the idea that cells can be classified in one of three major groups? Hint: This scientist analyzed the nucleic acid sequences among organisms to demonstrate the existence of three major groups of cells Woese Kitasato Pauling Fleming.

woese