Microbiology Dynamic Study Module and End of Chapter Questions -Chapter 1

How is an opportunistic pathogen different from a pathogen?

Opportunistic pathogens require reduced resistance of the host, such as a compromised immune system, in order to establish an infection and cause disease. True pathogens can cause disease in a patient with a healthy immune system. Opportunistic pathogens like the yeast Candida albicans may also cause disease if there is a shift in normal microbiota that allows the less abundant opportunist to thrive in light of limited competition;

We explore questions about the origins of disease and treatments through the scientific method. Which of the following would be the most likely order to apply the scientific method? State question - Formulate Hypothesis - Design Experiment - Collect Data - Draw Conclusions Design Experiment - Formulate Hypothesis - State Question - Collect Data - Draw Conclusions Formulate Hypothesis - State Question - Design Experiment - Collect Data - Draw Conclusions Design Experiment - Collect Data - Formulate Hypothesis - State Question - Draw Conclusions

State question - Formulate Hypothesis - Design Experiment - Collect Data - Draw Conclusions

Which of the following types of microscopy would be best to study how a novel virus interacts with its host cell? Transmission electron microscopy Fluorescent microscopy Darkfield microscopy Brightfield microscopy

TEM Transmission electron microscopy

Assume you are asked to view and draw all samples at a final magnification of 1000×. If the ocular lens is 10×, what objective lens should be in place as you draft your drawings?

The 100× oil objective would be in place;

Which of the following is not one of the four postulates of disease developed by Koch? The same organism must be present in every case of the disease. The organism must be re-isolated from the inoculated, diseased animal. The organism should be present in mixed culture. The isolated organism should cause the disease in question when it is introduced into a susceptible host.

The organism should be present in mixed culture.

Which of the following microscopy terms is correctly matched with its definition? Total magnification - the magnification resulting from multiplying the magnification of the ocular and objective lenses Oil immersion - oil used at 100x total magnification to prevent light from scattering Resolution - degree to which a substance bends light Refractive index -ability to distinguish two distinct points as separate points

Total magnification - the magnification resulting from multiplying the magnification of the ocular and objective lenses

__________ are just temporary passengers that do not persist as stable residents of our bodies. Resident microbiota Normal microbiota Transient microbiota Bioremediation

Transient Microbiota

Label and describe the function of each indicated part of the compound light microscope.

a. objective lens is closest to specimen, b. condenser sharpens the light into a precise cone, c. lamp provides a light source, d. fine focus knob allows for precision focusing;

Immersion oil improves resolution by: a. limiting light refraction. b. magnifying the specimen. c. improving specimen contrast. d. making light waves shorter. e. making light waves faster.

a; limiting light refraction.

Assume that you isolated a unicellular, non-nucleated cell from a deep-sea vent. Select the statement that is least likely regarding the cell you found. a. The cell is a prokaryote. b. The cell is a fungus or yeast. c. The cell is an archaea. d. The cell is not a pathogen. e. The cell is in Domain Archaea.

b; The cell is a fungus or yeast

Which of the following regions in the human body supports the greatest variety of microbial species? Urogenital tract Skin Gut Mouth, pharynx, upper respiratory system

gut

Acid-fast bacteria contain __________ in their cell wall.

mycolic acid;

A symbiotic relationship exists between two or more closely connected organisms. The relationship between one organism invading another and causing harm to that organism would be considered _______. commensalism planktonic parasitism mutualism

parasitism

Fill in the blanks: Bacteria are ______ cells in the domain . In contrast, the domain ________ includes unicellular and multicellular organisms that are made of __________ cells, or cells that have a nucleus and membrane-bound organelles.

prokaryotic Bacteria. Eukarya eukaryotic;

Escherichia coli O157:H7 may cause servere illness. "O157:H7" is the _______ designation of the organism. species genus strain domain

strain

A _______________is a genetic variant of the same species.

strain;

You suspect that your patient is suffering from tuberculosis and obtain a sputum sample. Which of the following staining procedures would be the most appropriate to diagnose your patient? Flagellar stain Gram stain Acid-fast stain Capsule stain

Acid-fast stain

_________ was the first scientist to observe bacteria under the microscope. Robert Hooke Joseph Lister Robert Koch Antonie van Leeuwenhoek

Antonie van Leewenhoeck

Fill in the blanks: ____________ are dormant structures that certain bacteria can make. These structures can be seen using the structural stain called the ______________ .

Bacterial endospores, endospore stain;

Which of the following is an incorrect statement about biofilms? An estimated 60 to 80% of infectious diseases in humans are due to biofilm-creating microbes. Biofilms can develop on nearly any surface. Biofilms are composed of planktonic bacteria. Biofilms are sticky communities made up of single or diverse species.

Biofilms are composed of planktonic bacteria.

Which of the following is not an accomplishment that is attributed to Louis Pasteur? Disproving spontaneous generation Developing the postulates of disease Demonstrating that yeast performed fermentation Developing the first vaccine to protect against anthrax

Developing the postulates of disease

Which of the following is the most general classification of an organism? Strain Species Genus Domain

Domain

List the following taxonomic groupings in order from general to specific. Phylum, Kingdom, Genus, Family, Class, Domain, Species, Order

Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species;

While many areas on and in the human body contain a variety of microbes, there are "microbe-free zones." Which of the following would not typically be a microbe-free zone? Uterus Human gut Blood Brain

Human gut

Which of the following statements about electron microscopy is false? It requires lengthy and complex sample preparation. It only produces black and white images. It has a maximum magnification of 1000x. All observed specimen are dead.

It has a maximum magnification of 1000x

Which of the following is an incorrect statement about aseptic technique? Aseptic processes are central to health care. It is a sterile technique. It was first developed by Ignaz Semmelweis. It is used to prevent contamination.

It is a sterile technique

Which of the following scientists investigated processes for aseptic surgery? Alexander Fleming Edward Jenner Robert Koch Joseph Lister

Joseph Lister

Why is it clinically helpful to know the Gram property of an organism?

Knowing Gram property is important because certain drugs are more effective against Gram-positive versus Gram-negative bacteria and vice versa.

Which of the following microbes is considered "nonliving?" Bacteria Archaea Viruses Fungi

Viruses

If you left out the safranin from your Gram staining procedure and observed your mixed culture after the application of alcohol-acetone, what would be the appearance of your Gram-positive and Gram-negative organisms, given you followed all steps in order and applied all other reagents correctly? Your Gram-positives would appear purple, and your Gram-negatives would be pink. Your Gram-positives would appear purple, and your Gram-negatives would be colorless. Your Gram-positives would appear pink, Gram-negatives would be colorless. Your Gram-positives would appear pink, Gram-negatives would be purple.

Your Gram-positives would appear purple, and your Gram-negatives would be colorless.

Classify the following as bright field, dark field, phase contrast, or differential interference contrast (DIC). a. Sample must be stained or have its own coloration to be seen: b. Specimen is illuminated with polarized light: c. Generates a falsely three-dimensional image: d. The simplest and most common form of light microscopy: e. Generates a negative image using a hollow cone of light: f. Generates a negative image in which light shifts are converted into visible changes in brightness and contrast:

a. Bright field, b. Differential interference contrast, c. Differential interference contrast, d. Bright field, e. Dark field, f. Phase contrast;

Indicate the true statements and then correct the false statements so that they are true. a. The Gram stain is a simple stain. b. Simple stains reveal information about size, shape, and arrangement. c. Bright field microscopy requires a stained sample. d. Dark field microscopy requires a stained sample. e. The acid-fast stain detects peptidoglycan in the cell walls of certain bacteria. f. Gram-positive bacteria have a thin peptidoglycan layer in the cell wall.

a. False. The Gram stain is a differential stain, b. True, c. True, d. False. Dark field microscopy does not require a stained sample, e. False. The acid-fast stain detects mycolic acid in the cell walls of certain bacteria, f. False. Gram-positive bacteria have a thick peptidoglycan layer in their cell wall;

Identify the following statements as observations or conclusions. The solution turned red. The bacterium is a rod shape. The cell died due to lack of nutrients. The bacterium is E. coli. The cell is Gram-positive. The bacterium is a pathogen. There are small green structures present upon performing the endospore stain. The solution remained clear after 10 hours of incubation. Fermentation occurred. Life comes from life.

a. Observation, b. Observation, c. Conclusion, d. Conclusion, e. Conclusion, f. Conclusion, g. Observation, h. Observation, i. Conclusion, j. Conclusion,

Indicate which form of electron microscopy is being described: SEM, TEM, or both? a. Images the external surface of a specimen b. Sample must be thinly sliced prior to viewing c. Provides details about internal structures of the sample d. Can be used to image viruses e. Provides black-and-white images f. Specimen is dead

a. SEM, b. TEM, c. TEM, d. Both, e. Both, f. Both

Over time, Koch's disease postulates have been rephrased in a variety of ways, but they still reflect the same process outlined by Robert Koch. The following are reworded versions of Koch's postulates. Based on the original postulates, put the following items in the correct order. a. Use the purified agent to cause infection in a test animal. b. Isolate an infectious agent from a diseased animal. c. Grow the infectious agent as a pure culture in the lab. d. From the test animal, re-isolate the infectious agent that was originally grown in pure culture.

b, Isolate an infectious agent from a diseased animal. d, From the test animal, re-isolate the infectious agent that was originally grown in pure culture. a, Use the purified agent to cause infection in a test animal. c; Grow the infectious agent as a pure culture in the lab.

Which of the following is/are true regarding our normal microbiota? Select all that apply: a. Our normal microbiota is easily disrupted by hygiene practices like hand washing. b. Our normal microbiota can include pathogens. c. Normal microbiota compete with pathogens. d. Normal microbiota may colonize us before we are even born. e. Normal microbiota changes over time. f. The normal microbiota that we have as adults is the same as we had as children.

b. Our normal microbiota is easily disrupted by hygiene practices like hand washing c. Normal microbiota compete with pathogens. d. Normal microbiota may colonize us before we are even born.

What best describes the relationship between host and pathogen? a. Mutualism b. Parasitism c. Commensalism d. Endosymbiosis

b. Parasitism

The success of the Gram stain is based on the difference in the composition of the _______ of bacterial cells. lagella plasma membranes cell walls capsules

cell walls

Which of the following is true? a. SEM is higher resolution than TEM. b. Most viruses can be seen using a light microscope. c. Simple staining involves an acidic and a basic dye in combination. d. Samples can be stained or unstained for light microscopy. e. These are all false statements.

d; Samples can be stained or unstained for light microscopy.

Fill in the blanks: In taxonomy, the broadest groupings are called _________ , which are further subdivided into six different _________ . The most specific or narrowest grouping is ____________ , which is the _____________ name in the binomial nomenclature system.

domains, kingdoms. species, second;

Select the most accurate statement: a. The Gram stain is a simple stain. b. Bacterial endospores appear green from the acid-fast stain. c. The acid-fast stain is used to detect bacteria that have a capsule. d. Bacterial flagella can only be seen with electron microscopes. e. The mordant in the Gram stain is iodine.

e; the mordant in the gram stain is iodine

Which of the following is not a domain? Fungi Bacteria Archaea Eukarya

fungi

The organism Candida albicans is classified as a __________ and grouped within the domain _________. fungus; Eukarya bacterium, Bacteria bacterium; Monera fungus; Monera

fungus; Eukarya

A colony (is a) _________. grouping of cells that developed from a single parent cell helps isolate a specific species of microbe for study pure culture mixed culture

grouping of cells that developed from a single parent cell