Final Exam!

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Which stain (from a list) would be helpful in determining the size and shape of a colorless bacterium WITHOUT fixing.

India ink stain or Nigrosin stain (correct)

Methylene blue

Crystal violet

Acidic Stain

In a Gram stain, a step could be ommitted and still alllow differentiation between Gram positive and Gram negative cells. Which step?

Application of the primary stain (crystal violet)

Addition of the mordant (iodine)

Decolorization with alcohol or acetone

Counterstaining with safranin or basic fuchsin (correct)

Which is NOT a type of inclusion (from a list)?

Glycogen granules

Lipid droplets

Ribosomes (correct)

Polyphosphate granules

How can genomes from microbes that cannot be grown in the lab still be studied?

Metagenomics Signup and view all the answers

Six Staphylococcus aureus cells were accidently inoculated into an uncooked pie. How many cells would be in the pie after 3 hours. Assume generation time of 60 minutes.

48 cells Signup and view all the answers

If an F+, Cys+ cell recombines with an F-, Cys- cell, what might happen to the F-,Cys- cell?

The recipient cell becomes F+ and Cys+ Signup and view all the answers

During PCR, instead of using DNA polymerase from Thermus aquaticus, human DNA polymerase is used. Starting with 1 molecule of DNA, after 3 full cycles are completed (assuming all other conditions remain the same), how many DNA molecules do you expect to see?

8 molecules Signup and view all the answers

How did the idea of spontaneous generation come about?

The belief that living organisms emerge from nonliving matter arose from observations such as flies emerging from manure, maggots from dead animals, and microorganisms appearing in liquids after a short period. Signup and view all the answers

What role do microorganisms play in the biological control of pests?

Certain microorganisms cause diseases in insects. Microorganisms that kill insects can be effective biological control agents because they are specific for the pest and do not persist in the environment. Signup and view all the answers

What is the role do microorganisms play in recycling elements?

All of the above. Signup and view all the answers

What role do microorganisms play in normal microbiota?

Normal microbiota are microorganisms that are found in and on the human body. They do not usually cause disease and can be beneficial. Signup and view all the answers

What role do microorganisms play in sewage treatment?

Organic matter in sewage is decomposed by bacteria into carbon dioxide, nitrates, phosphates, sulfate, and other inorganic compounds in a wastewater treatment plant. Signup and view all the answers

What role do microorganisms play in human insulin production?

Recombinant DNA techniques have resulted in insertion of the gene for insulin production into bacteria. These bacteria can produce human insulin inexpensively. Signup and view all the answers

What role does microorganisms play in vaccine production?

Microorganisms can be used as vaccines. Some microbes can be genetically modified to produce components of vaccines. Signup and view all the answers

What role do microorganisms play in biofilms?

Biofilms are aggregated bacteria adhering to each other and to a solid surface. Signup and view all the answers

Match the microorganisms in column A to their descriptions in column B.

Archaea = Prokaryote without peptidoglycan cell wall Algae = Cell wall made of cellulose; photosynthetic Bacteria = Cell wall made of peptidoglycan Fungi = Cell wall made of chitin Signup and view all the answers

Match the microorganisms in column A to their descriptions in column B.

<h1>Helminths = Multicellular animals Protozoa = Unicellular, complex cell structure lacking a cell wall Viruses = Not composed of cells</h1> Signup and view all the answers

What type of microorganism has a peptidoglycan cell wall, has DNA that is not contained in a nucleus, and has flagella?

Bacterium Signup and view all the answers

Where airborne microbes ended up in Pasteur’s experiment?

A Signup and view all the answers

Which of the following is a scientific name?

Mycobacterium tuberculosis Signup and view all the answers

Which of the following is not a characteristic of bacteria?

have the same shape Signup and view all the answers

Which of the following is the most important element of Koch’s germ theory of disease? The animal shows disease symptoms when

a microorganism is inoculated into the animal. Signup and view all the answers

Recombinant DNA is

the DNA resulting when genes of two different organisms are mixed. Signup and view all the answers

Which of the following statements is the best definition of biogenesis?

Living cells can only arise from preexisting cells. Signup and view all the answers

Which of the following is a beneficial activity of microorganisms?

all of the above all of the above Signup and view all the answers

It has been said that bacteria are essential for the existence of life on Earth. Which of the following is the essential function performed by bacteria?

decompose organic material and recycle elements Signup and view all the answers

Which of the following is an example of bioremediation?

application of oil-degrading bacteria to an oil spill Signup and view all the answers

Spallanzani’s conclusion about spontaneous generation was challenged because Antoine Lavoisier had just shown that oxygen was the vital component of air. Which of the following statements is true?

Some microbes do not require air. Signup and view all the answers

Which of the following statements about E. coli is false?

E. coli was the first disease-causing bacterium identified by Koch. Signup and view all the answers

How did the theory of biogenesis lead the way for the germ theory of disease?

By disproving spontaneous generation Signup and view all the answers

Even though the germ theory of disease was not demonstrated until 1876, why did Semmelweis (1840) and Lister (1867) argue for the use of aseptic techniques?

They both discovered that when they practiced the cleaning of these tools and hands, that less and less people started dying. Signup and view all the answers

Should antibacterial soaps and detergents be used in the home?

No, they contribute to antibiotic resistance and may harm the environment. Signup and view all the answers

Which is NOT an emerging pathogen as described in your text.

All of the Above Signup and view all the answers

Recombinant DNA technology has become an increasingly important part of our life. It is used for all of the following EXCEPT

synthesis of water. Signup and view all the answers

Development of emerging infectious disease can be a result of all of the following EXCEPT

use of genetically modified foods. Signup and view all the answers

Which of the following is the best definition of oxidative phosphorylation?

A proton gradient allows hydrogen ions to flow back into the cells through transmembrane protein channels, releasing energy that is used to generate ATP. Signup and view all the answers

In the figure, where is ATP produced?

E Signup and view all the answers

Which of the following statements is INCORRECT regarding prokaryotic cells?

They lack a plasma membrane. Signup and view all the answers

Which of the following statements regarding metabolism is FALSE?

Anabolic reactions are degradative. Signup and view all the answers

Which of the following pairs is mismatched?

safranin – acid dye Signup and view all the answers

All of the below are examples of a biofilm EXCEPT

archaea as part of the plankton community in the open ocean. Signup and view all the answers

In non-cyclic photophosphorylation, excited electrons ultimately

combine with hydrogens ions and NADP+ to produce NADPH Signup and view all the answers

Functions of the glycocalyx include all of the following EXCEPT

binary fission. Signup and view all the answers

A microorganism measures 5 μm in length. What is its length in mm, nm, and m?

0.005 mm (millimeters) 5000 nm (nanometers) 5×10^-6m (meters) Signup and view all the answers

Which type of microscope would be best to use to observe a stained bacterial smear

Compound light microscope Signup and view all the answers

Which type of microscope would be best to use to observe unstained bacterial cells: the cells are small, and no detail is needed

Darkfield microscope Signup and view all the answers

Which type of microscope would be best to use to observe unstained live tissue when it is desirable to see some intracellular detail?

Phase-contrast microscope Signup and view all the answers

Which type of microscope would be best to use to observe a sample that emits light when illuminated with ultraviolet light?

Fluorescence microscope Signup and view all the answers

Which type of microscope would be best to use to observe intracellular detail of a cell that is 1 μm long?

Electron microscope Signup and view all the answers

Which type of microscope would be best to use to observe unstained live cells in which intracellular structures are shown in color?

Differential interference contrast microscope Signup and view all the answers

Label the parts of the compound light microscope in the figure below, and then draw the path of light from the illuminator to your eye.

a = Ocular Lens b = Objective Lens c = Condenser Lens d = Diaphragm Signup and view all the answers

Calculate the total magnification of the nucleus of a cell being observed through a compound light microscope with a 10× ocular lens and an oil

1000X Signup and view all the answers

The maximum magnification of a compound microscope is

1500X Signup and view all the answers

The maximum magnification of an electron microscope

10,000,000X Signup and view all the answers

The maximum resolution of a compound microscope is

0.2 μm Signup and view all the answers

The maximum resolution of an electron microscope

10 pm Signup and view all the answers

One advantage of a scanning electron microscope over a transmission electron microscope is

Seeing three-dimensional detail. Signup and view all the answers

In a hypertonic solution, what is likely to happen to a protoplast?

Water will diffuse out of the protoplast. Signup and view all the answers

What is the fate of pyruvic acid in an organism that uses aerobic respiration?

It is converted into acetyl-CoA. Signup and view all the answers

An enzyme, citrate synthase, is inhibited by ATP. This is an example of:

Feedback Inhibition Signup and view all the answers

Given a "recipe" for a specific culture medium, identify a complex or defined medium.

Beef Nutrient Agar = Complex Medium Chicken Nutrient Agar = Complex Medium Glucose = Defined Medium K2HPO4 = Defined Medium Signup and view all the answers

Which of the following disinfectants from a given list acts by disrupting the plasma membrane?

bisphenols Signup and view all the answers

Which chemical method of microbial control damage DNA?

Aldehydes Signup and view all the answers

Repeating sequences of non-coding DNA that are used for forensic analysis is called

Short Tandem Repeats (STRs) Signup and view all the answers

If tryptophan is present, the repressible operon is:

Repressor becomes inactive Signup and view all the answers

What are key features of a restriction enzyme?

All of the above Signup and view all the answers

How is cDNA made?

made from mRNA by reverse transcription can be cloned in genomic libraries. Signup and view all the answers

Why is a mordant used in the Gram stain?

In a Gram stain, the mordant combines with the basic dye to form a complex that will not wash out of gram-positive cells. Signup and view all the answers

Why is a mordant used in the flagella stain?

In a flagella stain, the mordant accumulates on the flagella so that they can be seen with a light microscope. Signup and view all the answers

What is the purpose of a counterstain in the acid-fast stain?

A counterstain stains the colorless non–acid-fast cells so that they are easily seen through a microscope. Signup and view all the answers

What is the purpose of a decolorizer in the Gram stain?

In the Gram stain, the decolorizer removes the color from gram-negative cells. Signup and view all the answers

What is the purpose of a decolorizer in the acid-fast stain?

In the acid-fast stain, the decolorizer removes the color from non–acid-fast cells. Signup and view all the answers

Assume you stain Bacillus by applying malachite green with heat and then counterstain with safranin. Through the microscope, the green structures are

endospores. Signup and view all the answers

Three-dimensional images of live cells can be produced with

confocal microscopy. Signup and view all the answers

Carbolfuchsin can be used as a simple stain and a negative stain. As a simple stain, the pH is

higher than the negative stain. Signup and view all the answers

Looking at the cell of a photosynthetic microorganism, you observe the chloroplasts are green in brightfield microscopy and red in fluorescence microscopy. You conclude:

chlorophyll is fluorescent. Signup and view all the answers

Which of the following is not a functionally analogous pair of stains?

nigrosin and malachite green Signup and view all the answers

Which of the following pairs is mismatched?

none of the above Signup and view all the answers

Assume you stain Clostridium by applying a basic stain, carbolfuchsin, with heat, decolorizing with acid-alcohol, and counterstaining with an acidic stain, nigrosin. Through the microscope, the endospores are 1, and the cells are stained 2.

1—red; 2—colorless Signup and view all the answers

Assume that you are viewing a Gram-stained field of red cocci and blue rods through the microscope. You can safely conclude that you have

two different species. Signup and view all the answers

In 1996, scientists described a new tapeworm parasite that had killed at least one person. The initial examination of the patient’s abdominal mass was most likely made using

brightfield microscopy. Signup and view all the answers

Which of the following is not a modification of a compound light microscope?

electron microscopy Signup and view all the answers

In a Gram stain, a step could be omitted and still allow differentiation between gram-positive and gram-negative cells. What is it?

The counterstain (safranin) step Signup and view all the answers

Using a good compound light microscope with a resolving power of 0.3 μm, a 10× ocular lens, and a 100× oil immersion lens, would you be able to discern two objects separated by 3 μm? 0.3 μm? 300 nm?

All of the Above Signup and view all the answers

Endospores can be seen as refractile structures in unstained cells and as colorless areas in Gram-stained cells. Why is it necessary to do an endospore stain to verify the presence of endospores?

All of the above Signup and view all the answers

In 1882, German bacteriologist Paul Erhlich described a method for staining Mycobacterium and noted, “It may be that all disinfecting agents which are acidic will be without effect on this [tubercle] bacillus, and one will have to be limited to alkaline agents.” How did he reach this conclusion without testing disinfectants?

By observing the acid-fast staining properties of Mycobacterium Signup and view all the answers

Which of the graphs in the figure best illustrates the activity of an enzyme that is saturated with substrate?

c Signup and view all the answers

Cyanobacteria are a type of

photoautotroph. Signup and view all the answers

Which compound is being reduced in the reaction shown in the figure?

NAD+ Signup and view all the answers

An enzyme, citrate synthase, in the Krebs cycle is inhibited by ATP. This is an example of all of the following EXCEPT

competitive inhibition. Signup and view all the answers

Microorganisms are involved in each of the following processes EXCEPT

smog production. Signup and view all the answers

Microorganisms that catabolize sugars into ethanol and hydrogen gas would most likely be categorized as

heterolactic fermenters. Signup and view all the answers

Which of the following statements about gram-negative cell walls is FALSE?

They are sensitive to penicillin. Signup and view all the answers

Which of the following is not a distinguishing characteristic of prokaryotic cells?

They lack a plasma membrane. Signup and view all the answers

Which statement best describes what happens when a gram-positive bacterium is placed in distilled water and penicillin?

The cell will undergo osmotic lysis. Signup and view all the answers

Which statement best describes what happens when a gram-negative bacterium is placed in distilled water and penicillin?

Water will move into the cell. Signup and view all the answers

Which statement best describes what happens when a gram-positive bacterium is placed in an aqueous solution of lysozyme and 10% sucrose?

No change will result; the solution is isotonic. Signup and view all the answers

Which of the following statements best describes what happens to a cell exposed to polymyxins that destroy phospholipids?

Intracellular contents will leak from the cell. Signup and view all the answers

Which of the following is false about fimbriae?

They may be used for motility. Signup and view all the answers

Which of the following pairs is mismatched?

pili—reproduction Signup and view all the answers

You have isolated a motile, gram-positive cell with no visible nucleus. You can assume this cell has

ribosomes. Signup and view all the answers

The antibiotic amphotericin B disrupts plasma membranes by combining with sterols; it will affect all of the following cells except

gram-negative bacterial cells. Signup and view all the answers

Endospore formation is called

sporogenesis Signup and view all the answers

Endospore formation is initiated by

certain adverse environmental conditions Signup and view all the answers

Formation of a new cell from an endospore is called

germination Signup and view all the answers

Germination is triggered by

favorable growth conditions Signup and view all the answers

Match the structures in column A to their functions in column B.

Cell Wall = Protection from osmotic lysis Endospore = Resting Fimbriae = Attachment to surfaces Flagella = Motility Signup and view all the answers

Match the structures in column A to their functions in column B

Glycocalyx = Attachment to surfaces and Protection from phagocytes Pili = Motility and Transfer of genetic material Plasma membrane = Cell wall formation and Selective permeability Ribosomes = Protein synthesis Signup and view all the answers

Why is an endospore called a resting structure?

because it provides a method for one cell to “rest,” or survive, as opposed to grow and reproduce. Signup and view all the answers

Of what advantage is an endospore to a bacterial cell?

The protective endospore wall allows a bacterium to withstand adverse conditions in the environment. Signup and view all the answers

Compare and Contrast simple diffusion and facilitated diffusion.

Both allow materials to cross the plasma membrane from a high concentration to a low concentration without expending energy. Facilitated diffusion requires carrier proteins. Signup and view all the answers

Compare and contrast active transport and facilitated diffusion

Both require enzymes to move materials across the plasma membrane. In active transport, energy is expended. Signup and view all the answers

Compare and contrast active transport and group translocation

Both move materials across the plasma membrane with an expenditure of energy. In group translocation, the substrate is changed after it crosses the membrane. Signup and view all the answers

Why does penicillin have no effect on most gram-negative cells?

The outer layer of the gram-negative cells prevents penicillin from entering the cells. Signup and view all the answers

How can prokaryotic cells be smaller than eukaryotic cells and still carry on all the functions of life?

Prokaryotic cells lack membrane-bound organelles, relying on a simpler internal structure with components freely floating in the cytoplasm. Signup and view all the answers

Which of the following is NOT a functionally analogous pair?

cilia - pili Signup and view all the answers

By which of the following mechanisms can a cell transport a substance from a lower to a higher concentration?

active transport Signup and view all the answers

Robert Koch identified the cause of

anthrax. Signup and view all the answers

A virus measures 100 nm in length. What is its length in μm?

0.1 μm Signup and view all the answers

Which of the following uses glucose for carbon and energy?

chemoheterotroph Signup and view all the answers

Which statements correspond to amphibolic pathways?

Anabolic and catabolic reactions are joined through common intermediate.

They are shared metabolic pathways.

Feedback inhibition can help regulate rates of reactions.

Both types of reactions are necessary but do not occur simultaneously.

1, 2, 3 Signup and view all the answers

Which drawing in the figure is streptococci?

d Signup and view all the answers

Which microscope is used to see internal structures of cells in a natural state?

phase-contrast microscope Signup and view all the answers

Which of the following is NOT found or observed to occur in both mitochondria and prokaryotes?

cell wall Signup and view all the answers

Which microscope takes advantage of differences in the refractive indexes of cell structures?

phase-contrast microscope Signup and view all the answers

Which two staining techniques employ a mordant?

Gram stain; Flagella stain. Signup and view all the answers

Who challenged the idea of spontaneous generation with the concept of biogenesis?

Rudolf Virchow Signup and view all the answers

Which of the following statements about anaerobic respiration is FALSE?

It involves the reduction of an organic final electron acceptor. Signup and view all the answers

Differentiate the terms in each of the following pairs: etiology and pathogenesis

Etiology is the study of the cause of a disease, whereas pathogenesis is the manner in which the disease develops. Signup and view all the answers

The emergence of new infectious diseases is probably due to all of the following except

the need of bacteria to cause disease. Signup and view all the answers

All members of a group of ornithologists studying barn owls in the wild have had salmonellosis (Salmonella gastroenteritis). One birder is experiencing her third infection. What is the most likely source of their infections?

They are contaminating their hands while handling the owls and nests. Signup and view all the answers

Which of the following statements is false?

E. coli never causes disease. Signup and view all the answers

Which of the following is not one of Koch’s postulates?

The disease must be transmitted from a diseased animal to a healthy, susceptible animal by direct contact. Signup and view all the answers

Which one of the following diseases is not correctly matched to its reservoir?

anthrax—nonliving Signup and view all the answers

On September 6, a 6-year-old boy experienced fever, chills, and vomiting. On September 7, he was hospitalized with diarrhea and swollen lymph nodes under both arms. On September 3, the boy had been scratched and bitten by a cat. The cat was found dead on September 5, and Yersinia pestis was isolated from the cat. Chloramphenicol was administered to the boy from September 7, when Y. pestis was isolated from him. On September 17, the boy’s temperature returned to normal; and on September 22, he was released from the hospital.

identify the incubation period for this case of bubonic plague.

September 3–5 Signup and view all the answers

On September 6, a 6-year-old boy experienced fever, chills, and vomiting. On September 7, he was hospitalized with diarrhea and swollen lymph nodes under both arms. On September 3, the boy had been scratched and bitten by a cat. The cat was found dead on September 5, and Yersinia pestis was isolated from the cat. Chloramphenicol was administered to the boy from September 7, when Y. pestis was isolated from him. On September 17, the boy’s temperature returned to normal; and on September 22, he was released from the hospital.

Identify the prodromal period for this disease.

September 6–7 Signup and view all the answers

A Maryland woman was hospitalized with dehydration; Vibrio cholerae and Plesiomonas shigelloides were isolated from the patient. She had neither traveled outside the United States nor eaten raw shellfish during the preceding month. She had attended a party 2 days before her hospitalization. Two other people at the party had acute diarrheal illness and elevated levels of serum antibodies against Vibrio. Everyone at the party ate crabs and rice pudding with coconut milk. Crabs left over from this party were served at a second party. One of the 20 people at the second party had onset of mild diarrhea; specimens from 14 of these people were negative for vibriocidal antibodies.

This is an example of

vehicle transmission. Signup and view all the answers

A Maryland woman was hospitalized with dehydration; Vibrio cholerae and Plesiomonas shigelloides were isolated from the patient. She had neither traveled outside the United States nor eaten raw shellfish during the preceding month. She had attended a party 2 days before her hospitalization. Two other people at the party had acute diarrheal illness and elevated levels of serum antibodies against Vibrio. Everyone at the party ate crabs and rice pudding with coconut milk. Crabs left over from this party were served at a second party. One of the 20 people at the second party had onset of mild diarrhea; specimens from 14 of these people were negative for vibriocidal antibodies.

The etiologic agent of the disease is

Vibrio cholerae Signup and view all the answers

A Maryland woman was hospitalized with dehydration; Vibrio cholerae and Plesiomonas shigelloides were isolated from the patient. She had neither traveled outside the United States nor eaten raw shellfish during the preceding month. She had attended a party 2 days before her hospitalization. Two other people at the party had acute diarrheal illness and elevated levels of serum antibodies against Vibrio. Everyone at the party ate crabs and rice pudding with coconut milk. Crabs left over from this party were served at a second party. One of the 20 people at the second party had onset of mild diarrhea; specimens from 14 of these people were negative for vibriocidal antibodies.

The source of the disease was

crabs Signup and view all the answers

Differentiate the terms in each of the following pairs: infection and disease

Infection refers to the colonization of the body by a microorganism. Disease is any change from a state of health. A disease may, but does not always, result from infection. Signup and view all the answers

Differentiate the terms in each of the following pairs: communicable disease and noncommunicable disease

A communicable disease is a disease that is spread from one host to another, whereas a noncommunicable disease is not transmitted from one host to another. Signup and view all the answers

Match

symbiosis (encompasses them all) = unlike organisms living together (Ex. coral and zooxanthellae) commensalism = one of the organisms benefits and the other is unaffected (Ex.corynebacteria living on the surface of the eye) mutualism = both organisms benefit (Ex. E. coli receives nutrients and a constant temperature in the large intestine and produces vitamin K and certain B vitamins that are useful for the human host.) parasitism = one organism benefits while the other is harmed(Ex. Salmonella enterica receives nutrients and warmth in the large intestine, and the human host experiences gastroenteritis or typhoid fever.) Signup and view all the answers

Indicate whether each of the following conditions is typical of subacute, chronic, or acute infections.

<h1>Subacute = The patient has no apparent symptoms and is a known carrier. Chronic = The patient experiences cough and breathing difficulty for months. Acute Infections = The patient experiences a rapid onset of malaise; symptoms last 5 days.</h1> Signup and view all the answers

Among hospital patients who have infections, one-third did not enter the hospital with the infection but rather acquired it in the hospital. How do they acquire these infections?

Hospital patients may be in a weakened condition and therefore predisposed to infection. Signup and view all the answers

Among hospital patients who have infections, one-third did not enter the hospital with the infection but rather acquired it in the hospital. What is the method of transmission of these infections?

Pathogenic microorganisms are generally transmitted to patients by contact and airborne transmission. Signup and view all the answers

Among hospital patients who have infections, one-third did not enter the hospital with the infection but rather acquired it in the hospital. What is the reservoir of infection?

The reservoirs of infection are the hospital staff, visitors, and other patients. Signup and view all the answers

Distinguish symptoms from signs as signals of disease.

<h1>Symptoms = Changes in body function that the patient feels Signs = Objective changes that the physician can observe and measure Symptoms = weakness or pain are not measurable by a physician.</h1> Signup and view all the answers

How can a local infection become a systemic infection?

When microorganisms causing a local infection enter a blood or lymph vessel and are spread throughout the body, a systemic infection can result. Signup and view all the answers

Why are some organisms that constitute the normal microbiota described as commensals, whereas others are described as mutualistic?

Mutualistic microorganisms are providing a chemical or environment that is essential for the host. Commensal organisms are not essential; another microorganism might serve the function as well. Signup and view all the answers

Put the following in the correct order to describe the pattern of disease: period of convalescence, prodromal period, period of decline, incubation period, period of illness.

Incubation period, prodromal period, period of illness, period of decline (may be crisis), period of convalescence. Signup and view all the answers

Ten years before Robert Koch published his work on anthrax, Anton De Bary showed that potato blight was caused by the alga Phytophthora infestans. Why do you suppose we use Koch’s postulates instead of something called “De Bary’s postulates”?

Koch's postulates provided a method to link specific microorganisms to diseases, while De Bary's work on potato blight lacked a general method for identifying the causes of infections. Signup and view all the answers

Name the method of transmission of each of the following diseases:

malaria = Mosquito tuberculosis = Air via respiratory droplets salmonellosis = contaminated food or water, often through the consumption of undercooked or raw foods. streptococcal pharyngitis = respiratory droplets or direct contact with respiratory secretions Signup and view all the answers

Name the method of transmission of each of the following diseases:

mononucleosis = close contact with saliva, such as kissing or sharing utensils, measles = respiratory droplets when an infected person coughs or sneezes. Hepatitis A = ingestion of contaminated food or water, or through close contact with an infected person's stool. Tetanus = contamination of wounds with the spores of the bacterium Clostridium tetani Signup and view all the answers

Name the method of transmission of each of the following diseases:

<h1>Hepatitis B = Transmitted through exposure to infected blood, semen, or other body fluids Chlamydial urethritis = sexual contact</h1> = Signup and view all the answers

Three days before a nurse developed meningococcemia, she assisted with intubation of a patient with a Neisseria meningitidis infection. Of the 24 medical personnel involved, only this nurse became ill. The nurse recalled that she was exposed to nasopharyngeal secretions and did not receive antibiotic prophylaxis. What two mistakes did the nurse make?

Not wearing a mask and not taking an antibiotic Signup and view all the answers

Three days before a nurse developed meningococcemia, she assisted with intubation of a patient with a Neisseria meningitidis infection. Of the 24 medical personnel involved, only this nurse became ill. The nurse recalled that she was exposed to nasopharyngeal secretions and did not receive antibiotic prophylaxis. How is meningitis transmitted?

Meningitis is the bacterial disease that can be transmitted through nasal and oral secretions -like coughing and sneezing. It is not highly contagious. Signup and view all the answers

Which of the following statements concerning pathology, infection, and disease is true?

Pathology refers to the study of structural and functional changes that occur in the body as a result of a disease. Signup and view all the answers

Which of the following is an example of the symbiotic relationship known as mutualism?

E. coli within the large intestine Signup and view all the answers

Koch's postulates established criteria for proving that a specific organism causes a specific disease. Which of the following is NOT one of the criteria given by Koch's postulates?

The pathogen must be isolated from inoculated animals and must be different from the original organism. Signup and view all the answers

Which of the following is classified as a latent disease?

shingles Signup and view all the answers

Which of the following statements about the development of infectious diseases is correct?

The period of convalescence is the time during which the person regains health and fully recovers (back to the pre-disease state). Signup and view all the answers

Which of the following is a protozoan zoonosis that can be transmitted by direct contact?

Toxoplasmosis Signup and view all the answers

Which of the following would be an example of disease transmission via indirect contact?

A student sneezes on her test booklet. The instructor grades it and catches her cold. Signup and view all the answers

As a health care worker, you are keenly aware of how important it is to avoid harming patients. You worry about inadvertently transmitting an infectious disease to an already compromised individual. According to the CDC, what is the most important thing you can do to avoid this?

wash my hands before and after interacting with any patient Signup and view all the answers

The following choices list several types of diseases, along with factors that may contribute to their emergence. Which disease and associated factor do NOT match?

emergence of avian influenza A (H5N1); use of antibiotics Signup and view all the answers

Match

Etiology = The study of the cause of a disease Infectious Disease = Disease directly caused by microorganisms and nit by other means, for example, genetic or degenerative diseases Germ Theory of Disease = This theory states that microorganisms cause infectious disease Koch's Postulates = Experimental requirements for identifying the agent of an infectious disease Signup and view all the answers

Match

Diseased or Dead Animal = Original source of the infectious microbial agent Healthy Laboratory Animal = Organism injected with a potential infectious agent Microscope = Tool used to view and identify individual microorganism Growth Media = Nutrient-rich environment for isolating and culturing microorganisms Signup and view all the answers

Which statements accurately describe Koch’s postulates?

ALL OF THE ABOVE Signup and view all the answers

This activity presents experimental results obtained when a suspected pathogen was tested and asks you to identify appropriate conclusions based on each scenario.

A rabbit was found to have floppy ear disease, which causes long-ear infections. Its etiology (cause) is unknown. Unknown Microorganism X from the infected rabbit’s right ear is successfully isolated and cultured on laboratory growth media. The ear of a healthy laboratory mouse is then inoculated with isolated microorganism, and after a period of time, no disease is observed. Which of the following statements accurately describe(s) the conclusion(s) that can be drawn from this experiment?

Microorganism X modified its cell wall structure while being cultured, and is no longer infectious to rabbits. = Not an Accurate Conclusion Healthy laboratory organisms rarely show signs and symptoms of infection and disease. = Not an Accurate Conclusion A laboratory mouse might not be an appropriate, susceptible host; an experiment with a laboratory rabbit may be needed. = Accurate Conclusion Microorganism X might not be linked to floppy ear disease, because the inoculated mouse remained healthy. = Accurate Conclusion Signup and view all the answers

Match

Benefit = The steps are designed to systematically link a pathogen to a specific infectious disease Benefit = Laboratory findings provide experimental evidence that support the germ theory of disease Limitation = Some infectious agents have specific growth requiements that prevent them from being artificially cultured in the laboratory Limitation = Different pathogens can be produce the same signs and symptoms, making it difficult to determine which microorganism is causing a disease Signup and view all the answers

Match

<h1>Benefit = Healthy, suspectiable animals can be used as modell organisms for testing many types of infections, thus avoiding the unethical inoculation of healthy human hosts Limitation = Some pathogens cause several different diseases, which makes it difficult to link one pathogen to one disease using Koch's postulates</h1> = Signup and view all the answers

During a six-month period, 239 cases of pneumonia occurred in a town of 300 people. A clinical case was defined as fever ≥ 39°C lasting >2 days with three or more symptoms (i.e., chills, sweats, severe headache, cough, aching muscles/joints, fatigue, or feeling ill). A laboratory-confirmed case was defined as a positive result for antibodies against Coxiella burnetii. Before the outbreak, 2000 sheep were kept northwest of the town. Of the 20 sheep tested from the flock, 15 were positive for C. burnetii antibodies. Wind blew from the northwest, and rainfall was 0.5 cm compared with 7 to 10 cm during each of the previous three years.

The etiologic agent of the disease in the situation is

Coxiella burnetii Signup and view all the answers

A commensal bacterium

may also be an opportunistic pathogen. Signup and view all the answers

One effect of washing regularly with antibacterial agents is the removal of normal microbiota. This can result in

increased susceptibility to disease. Signup and view all the answers

The major significance of Robert Koch's work is that

microorganisms cause disease. Signup and view all the answers

Focal infections initially start out as

local infections. Signup and view all the answers

Malaria is an infectious disease caused by infection with a protozoan. In certain tropical regions, malaria is constantly present. We would say that malaria is a(n) __________ disease in these regions.

endemic Signup and view all the answers

Symptoms of disease differ from signs of disease in that symptoms

are changes felt by the patient. Signup and view all the answers

Which of the following definitions is INCORRECT?

secondary infection: a long-lasting illness Signup and view all the answers

The CDC is located in

Atlanta, GA. Signup and view all the answers

A researcher has performed a prospective study on a disease. To which specific kind of epidemiological study is this referring?

descriptive Signup and view all the answers

Which advance (from a list) occured during the Second Golden Age of Microbiology?

All of the Above Signup and view all the answers

Which advance (from a list) occured during the Second Golden Age of Microbiology?

All of the Above Signup and view all the answers

Which advance (from a list) occured during the Second Golden Age of Microbiology?

ALL OF THE ABOVE Signup and view all the answers

Which substance in the following reaction is being reduced?

acetaldehyde Signup and view all the answers

Which of the following reactions produces the most molecules of ATP during aerobic metabolism?

acetyl CoA → CO2 + H2O Signup and view all the answers

Which of the following processes does not generate ATP?

the Calvin-Benson cycle Signup and view all the answers

Which of the following compounds has the greatest amount of energy for a cell?

glucose Signup and view all the answers

Which of the following is the best definition of the Krebs cycle?

a series of chemical reactions in which NADH is produced from the oxidation of pyruvic acid Signup and view all the answers

Which of the following is the best definition of respiration?

a sequence of carrier molecules with the final electron acceptor from the environment Signup and view all the answers

Which culture produces the most lactic acid?

E. coli growing in glucose broth at 35°C without O2 for 5 days Signup and view all the answers

Which culture produces the most ATP?

E. coli growing in glucose broth at 35°C with O2 for 5 days Signup and view all the answers

Which culture uses NAD+?

both a and b Signup and view all the answers

Which culture uses the most glucose?

E. coli growing in glucose broth at 35°C without O2 for 5 days Signup and view all the answers

Define oxidation-reduction

A coupled reaction in which one substance loses electrons and another gains electrons. Signup and view all the answers

What is the difference between aerobic and anaerobic?

The final electron acceptor in aerobic respiration is molecular oxygen; in anaerobic respiration, it is another inorganic molecule. Signup and view all the answers

What is the difference between respiration and fermentation?

The final electron acceptor in respiration is usually inorganic; in fermentation it is usually organic. Signup and view all the answers

What is the difference between cyclic and noncyclic photophosphorylation?

In cyclic photophosphorylation, electrons are returned to chlorophyll. In noncyclic photophosphorylation, chlorophyll receives electrons from hydrogen atoms. Signup and view all the answers

All of the energy-producing biochemical reactions that occur in cells, such as photophosphorylation and glycolysis, are _____ reactions.

Oxidation Signup and view all the answers

Match: What are their carbon sources?

Photoautotroph = CO2 Photoheterotroph = Light Chemoautotroph = Organic molecules Chemoheterotroph = Light Signup and view all the answers

Match: What are their energy sources?

Photoautotroph = CO2 Photoheterotroph = Inorganic molecules Chemoautotroph = Organic molecules Chemoheterotroph = Organic molecules Signup and view all the answers

Explain why, even under ideal conditions, Streptococcus grows slowly.

Mainly because they use anaerobic respiration thus produce only a little amount of ATP Signup and view all the answers

Microorganisms placed in high concentrations of salts and sugars undergo lysis.

False Signup and view all the answers

A population of cells carrying a desired plasmid is called a

clone. Signup and view all the answers

Which of the following does NOT achieve sterilization?

pasteurization Signup and view all the answers

A sample of milk is tested for its bacterial content in a plate count assay. A one-milliliter sample of the milk is diluted in a 1:10 dilution series. One milliliter of the third dilution tube is plated in a pour plate. After incubation, the plate has 54 colonies, indicating that the original milk sample contained

54,000 cells per milliliter. Signup and view all the answers

Culture 1: F+, leucine+, histidine+ Culture 2: F-, leucine-, histidine-

In the table, if culture 1 mutates to Hfr, what will be the result of conjugation between the two cultures?

1 will remain the same; recombination may occur in 2 Signup and view all the answers

An experiment began with 4 cells in log phase and ended with 128 cells. How many generations did the cells go through?

5 Signup and view all the answers

Which enzyme catalyzes the following reaction? 2H2O2 → 2H2O + O2

catalase Signup and view all the answers

The biosafety level (BSL) for most introductory microbiology laboratories is

BSL-1. Signup and view all the answers

A culture medium consisting of agar, peptone, and beef heart is a

complex medium. Signup and view all the answers

The term aerotolerant anaerobe refers to an organism that

does not use oxygen but tolerates it. Signup and view all the answers

All of the following are effective for destroying prions EXCEPT

boiling. Signup and view all the answers

An advantage of cDNA over genomic DNA is that it

lacks introns. Signup and view all the answers

Which of the following could be used to sterilize plastic Petri plates in a plastic wrapper?

gamma radiation Signup and view all the answers

Medium 1 is

both selective and differential. Signup and view all the answers

Medium 2 is

selective Signup and view all the answers

Which of the lines best depicts the log phase of a thermophile incubated at room temperature?

c Signup and view all the answers

Which of the lines best depicts the log phase of Listeria monocytogenes growing in a human?

a Signup and view all the answers

Assume you inoculated 100 facultatively anaerobic cells onto nutrient agar and incubated the plate aerobically. You then inoculated 100 cells of the same species onto nutrient agar and incubated the second plate anaerobically. After incubation for 24 hours, you should have

the same number of colonies on both plates. Signup and view all the answers

The term trace elements refers to

small mineral requirements. Signup and view all the answers

Which one of the following temperatures would most likely kill a mesophile?

60°C Signup and view all the answers

Which of the following is not a characteristic of biofilms?

iron deficiency Signup and view all the answers

Which of the following types of media would not be used to culture aerobes?

reducing media Signup and view all the answers

An organism that has peroxidase and superoxide dismutase but lacks catalase is most likely an

aerotolerant anaerobe. Signup and view all the answers

The ability of some microbes, such as Trypanosoma or Giardia to alter their surface molecules and evade destruction by the host's antibodies is called

antigenic variation. Signup and view all the answers

Which of the following toxins and descriptions do NOT match?

Vibrio enterotoxin: a superantigen that destroys epithelial cells Signup and view all the answers

Which of the following statements about exotoxins is generally FALSE?

They are resistant to heat. Signup and view all the answers

Which of the following is NOT a cytopathic effect (CPE) of viruses?

All of the listed choices are possible cytopathic effects of viruses. Signup and view all the answers

Which type of bacterial enzyme helps spread Streptococcus pyogenes by digesting blood clots?

fibrinolysin Signup and view all the answers

Which statement regarding endotoxins is true?

One consequence of endotoxins is the activation of blood-clotting proteins. Signup and view all the answers

In which of the following cases would the Limulus amebocyte lysate (LAL) assay be used?

to ensure that a sterilized medical device is free of endotoxin Signup and view all the answers

Which of the following would be an example of an infection initiated via the parenteral route?

An individual contracts hepatitis B from an accidental stick with a contaminated needle. Signup and view all the answers

Which of the following is an example of direct damage due to bacterial infection?

the invasion and lysis of intestinal cells by E. coli Signup and view all the answers

All of the following contribute to a pathogen's invasiveness EXCEPT

toxins. Signup and view all the answers

All of the following are methods of avoiding host antibodies EXCEPT

membrane-disrupting toxins. Signup and view all the answers

A pathogen that is capable of antigenic variation can ________________.

avoid host immune defenses Signup and view all the answers

Which of the following statements about adherence is true?

Most bacterial adhesins are glycoproteins or lipoproteins. Signup and view all the answers

All of the following are used by bacteria to attach to host cells EXCEPT

A-B toxins. Signup and view all the answers

The ID50 is

the dose that will cause an infection in 50 percent of the test population. Signup and view all the answers

Ergot and aflatoxin are toxins sometimes found in grains contaminated with fungi.

True Signup and view all the answers

Certain traits that allow pathogens to create infection and cause disease are termed

virulence factors. Signup and view all the answers

Which of the following enzymes breaks down the "glue" that holds cells together?

Hyaluronidase Signup and view all the answers

Which of the following virulence factors would be found in Staphylococcus aureus?

Staphylokinase Signup and view all the answers

How do fibrinolysins enhance a pathogen's virulence?

They break down fibrin proteins that are involved in clot formation, allowing the cells to penetrate deep into damaged skin. Signup and view all the answers

Siderophores are bacterial proteins that compete with the host's

iron-transport proteins. Signup and view all the answers

Which of the following statements about lysogenic conversion is true?

Exotoxin production by bacteria is frequently the result of a lysogenic infection. Signup and view all the answers

In mice, the LD50 for staphylococcal enterotoxin is 1350 ng/kg, and the LD50 for Shiga toxin is 250 ng/kg. Which of the following statements is true?

Shiga toxin is more lethal than staphylococcal enterotoxin. Signup and view all the answers

Which of the following cytopathic effects is cytocidal?

release of enzymes from lysosomes Signup and view all the answers

Antibiotics can lead to septic shock if used to treat

gram-negative bacterial infections. Signup and view all the answers

The most frequently used portal of entry for pathogens is the

mucous membranes of the respiratory tract. Signup and view all the answers

Symptoms of protozoan and helminthic diseases are due to

tissue damage due to growth of the parasite on the tissues, waste products excreted by the parasite, and products released from damaged tissues. Signup and view all the answers

Most fungi grow best at pH

5 Signup and view all the answers

A suspension of 106 Bacillus cereus endospores was put in a hot-air oven at 170°C. Plate counts were used to determine the number of endospores surviving at the time intervals shown.

In the figure, the thermal death point for this culture is

The answer cannot be determined based on the information provided Signup and view all the answers

Patients with indwelling catheters (long-term tubes inserted into body orifices for drainage, such as through the urethra and into the urinary bladder) are susceptible to infections because

biofilms develop on catheters. Signup and view all the answers

If you knew the sequence of nucleotides within a gene, which one of the following could you determine with the most accuracy?

the primary structure of the protein Signup and view all the answers

If you were preparing nutrient agar at home and did not have an autoclave, what could you use to sterilize the nutrient agar?

pressure cooker at 121°C for 15 minute Signup and view all the answers

Which of the following best describes the pattern of microbial death?

The cells in a population die at a constant rate. Signup and view all the answers

One advantage of a viral vector over a plasmid vector is that the

viral vector can accept much larger pieces of DNA. Signup and view all the answers

A gene is defined as

a sequence of nucleotides in DNA that codes for a functional product. Signup and view all the answers

The fact that people continue to be concerned about the safety of DNA technology can be attributed to the following:

Both that it is impossible to prove something is safe under all conditions and that science can only provide supporting evidence for hypotheses. Signup and view all the answers

If cells are grown in media containing amino acids labeled with radioactive nitrogen (15N), most of the radioactivity will be found in the cells'

DNA and proteins. Signup and view all the answers

Which of the following is NOT a desired characteristic of DNA vectors used in gene cloning procedures?

large size Signup and view all the answers

In the figure, which line best depicts a facultative anaerobe in the absence of O2?

b Signup and view all the answers

During which growth phase will gram-positive bacteria be most susceptible to penicillin?

log phase Signup and view all the answers

The reaction catalyzed by reverse transcriptase is

mRNA → cDNA. Signup and view all the answers

Which of the following is NOT a product of transcription?

a new strand of DNA Signup and view all the answers

A kitchen countertop has a spill of vegetable oil that was wiped up but a film remains. What should be the next step in disinfecting this surface?

warm soapy scrub Signup and view all the answers

Which of the following statements regarding a bacterium that is R+ is FALSE?

It is F+. Signup and view all the answers

A source of heat-stable DNA polymerase is

Thermus aquaticus. Signup and view all the answers

In the figure, which model of the lac operon correctly shows RNA polymerase, lactose, and repressor protein when the structural genes are being transcribed?

d Signup and view all the answers

Which of the following pairs of terms is mismatched?

bacteriostatic – kills vegetative bacterial cells Signup and view all the answers

Repair of damaged DNA, in some instances and mechanisms, might be viewed as a race between an endonuclease and

methylase. Signup and view all the answers

Which of the following is NOT an agricultural product made by DNA techniques?

pectinase Signup and view all the answers

According to the operon model, for the synthesis of an inducible enzyme to occur, the

substrate must bind to the repressor. Signup and view all the answers

There have been several changes in taxonomy over the years. Who proposed the current taxonomy described in your text with three Domains (1978):

Woese Signup and view all the answers

Use of culture independent techniques like rRNA sequencing and FISH increased our understanding of microbial diversity. Why should microbiologists still attempt to grow new species?

Yes, because there are many species yet to be discovered, mutations occur, exploration of new places leads to the possibility of new microbes Signup and view all the answers

Gram-negative rods that are aerobic and non-fermenting:

non-fermenters or non-fermentative bacteria. or often opportunistic pathogens Signup and view all the answers

In what ways has PrPSc NOT been transmitted?

Airborne transmission Signup and view all the answers

What phyla do the Methanobacteria and Halobacteria belong to?

Euryarchaeota Signup and view all the answers

During development of disease, what defines a short period after incubation; early, mild symptoms

Prodromal period Signup and view all the answers

Of a list, which are factors that determine the distribution and composition of normal microbiota?

All of the Above Signup and view all the answers

What are the exceptions to Koch's postulates?

All of the Above Signup and view all the answers

A mosquito carrying the causative agent of malaria bites a human. What mode and type of transmission is this?

Arthropod vector transmission Signup and view all the answers

Of a list, which epidemiologist is best described as using analytical epidemiology to address an issue?

Florence Nightingale Signup and view all the answers

Incidence of a specific notifiable disease

All of the Above Signup and view all the answers

Which describes infectious dose (given ID50 and LD50)?

The most infectious dose Signup and view all the answers

What cell wall components prevent phagocytosis?

the M protein and waxy lipid (mycolic acid in Mycobacterium) Signup and view all the answers

Compare exotoxins and endotoxins

Exotoxin = Secreted to the outside of the bacteria Endotoxin = Part of outer portion of cell wall in gram-negative bacteria Exotoxin = Most are proteins/enzymes Endotoxin = Most are lipids Signup and view all the answers

Compare exotoxins and endotoxins

Endotoxin = Released during bacterial multiplication and lysis Endotoxin = Work by stimulating macrophages to release cytokines at toxic levels Exotoxin = Soluble in fluid and easily diffuses into the bloodstream Exotoxin = Produced by gram-negative or gram-positive bacteria Signup and view all the answers

Compare exotoxins and endotoxins

<h1>Exotoxin = Produce specific signs and symptoms of disease Endotoxin = Produce fever</h1> = Signup and view all the answers

How do protozoa evade host defenses?

All of the Above Signup and view all the answers

Which of the following exhibits the highest phagocytic activity?

macrophages Signup and view all the answers

Which of the following are best described as short chains of amino acids that are very stable and can have a variety of different antimicrobial activities, such as forming pores in bacterial plasma membranes and inhibiting cell wall synthesis?

antimicrobial peptides Signup and view all the answers

Each of the following provides protection from phagocytic digestion EXCEPT

formation of phagolysosomes. Signup and view all the answers

Innate immunity

is nonspecific and present at birth. Signup and view all the answers

Which statement regarding the lymphatic system is true?

Lymphatic capillaries possess one-way valves. These valves permit the uptake of fluid from the body but do not allow the fluid to flow back out of the capillaries into the intracellular spaces. Signup and view all the answers

You note that the body temperature of one of your patients is starting to increase. As a result, you can infer that all of the following may be occurring in this patient EXCEPT __________.

dilation of blood vessels Signup and view all the answers

Which of the following can defend the body by either opsonizing bacteria, lysing bacteria, and/or promoting inflammation?

Alpha and beta interferons Signup and view all the answers

Normal microbiota provide resistance to disease in all of the following ways except __________________.

serving as prebiotics Signup and view all the answers

All of the following increase blood vessel permeability EXCEPT

lysozymes. Signup and view all the answers

All of the following pertain to fever EXCEPT that it

accelerates microbial growth by increasing iron absorption from the digestive tract. Signup and view all the answers

Which of the following is an effect of opsonization?

increased adherence of phagocytes to microorganisms Signup and view all the answers

Which of the following statements concerning phagocytosis is true?

Bacteria are digested when the phagosome fuses with a lysosome. Signup and view all the answers

If one is examining a blood smear from a patient with a parasitic worm infection, which of the following leukocytes would be found in increased numbers?

eosinophils Signup and view all the answers

Which non-specific defense mechanism is mismatched with its associated body structure or body fluid?

mucociliary escalator – intestines Signup and view all the answers

All of the following protect the skin and mucous membranes from infection EXCEPT

HCl. Signup and view all the answers

The lectin pathway for complement action is initiated by

mannose on the surface of microbes. Signup and view all the answers

Which of the following statements about innate immunity is true?

Innate immunity is present at birth. Signup and view all the answers

Lysozyme and the antibiotic penicillin have similar mechanisms of action in that they both cause damage to the bacterial

cell wall. Signup and view all the answers

Which of the following statements about beta interferons is true?

It acts as a signal that induces uninfected cells to produce antiviral proteins. Signup and view all the answers

Unbroken skin poses a substantial barrier to microbes. All of the following contribute to this barrier except

complement proteins found in perspiration Signup and view all the answers

The complement protein cascade is the same for the classical pathway, alternative pathway, and lectin pathway after the point in the cascade where the activation of ________ takes place.

C3 Signup and view all the answers

Which of the following is mismatched?

chemotaxis – chemical degradation inside a phagolysosome Signup and view all the answers

TLRs attach to all of the following EXCEPT

AMPs. Signup and view all the answers

Which of the following statements is TRUE?

There are at least thirty complement proteins. Signup and view all the answers

The thermal death time for a suspension of Bacillus subtilis endospores is 30 minutes in dry heat and less than 10 minutes in an autoclave. Which type of heat is more effective?

Autoclave Signup and view all the answers

If pasteurization does not achieve sterilization, why is pasteurization used to treat food?

Because it destroys most organisms that cause disease or rapid spoilage of food. Signup and view all the answers

Which factors can alter thermal death point?

All of the Above Signup and view all the answers

The antimicrobial effect of gamma radiation is due to (a)__ . The antimicrobial effect of ultraviolet radiation is due to (b)_

(a) the ability of ionizing radiation to break DNA (b) formation of thymine dimers. Signup and view all the answers

How do autoclaving, hot air, and pasteurization illustrate the concept of equivalent treatments?

All three processes kill microorganisms; however, as moisture and/or temperatures are increased, less time is required to achieve the same result. Signup and view all the answers

How do salts and sugars preserve foods?

Salts and sugars create a hypertonic environment. Signup and view all the answers

Name one food that is preserved with sugar and one preserved with salt.

<h1>Sugar = Jams and jellies Salt = Meats</h1> = Signup and view all the answers

The use-dilution values for two disinfectants tested under the same conditions are as follows: Disinfectant A—1:2; Disinfectant B—1:10,000. If both disinfectants are designed for the same purpose, which would you select?

Disinfectant B—1:10,000 Signup and view all the answers

Which of the following does not kill endospores?

pasteurization Signup and view all the answers

Which of the following is most effective for sterilizing mattresses and plastic Petri dishes?

ethylene oxide Signup and view all the answers

Which of these disinfectants does not act by disrupting the plasma membrane?

halogens Signup and view all the answers

Which of the following cannot be used to sterilize a heat-labile solution stored in a plastic container?

autoclaving Signup and view all the answers

Which of the following is used to control microbial growth in foods?

organic acids Signup and view all the answers

Which disinfectant is the most effective?

A only Signup and view all the answers

Which disinfectant(s) is (are) bactericidal?

A, C, and D Signup and view all the answers

Which of the following is not a characteristic of quaternary ammonium compounds?

sporicidal Signup and view all the answers

A classmate is trying to determine how a disinfectant might kill cells. You observed that when he spilled the disinfectant in your reduced litmus milk, the litmus turned blue again. You suggest to your classmate that

the disinfectant might oxidize molecules. Signup and view all the answers

Which of the following is most likely to be bactericidal?

ionizing radiation Signup and view all the answers

Which disinfectant was the most effective against the organism?

Disinfectant Z Signup and view all the answers

Transfer of DNA from a donor to a recipient cell by a bacteriophage.

transduction Signup and view all the answers

Transfer of DNA from a donor to a recipient as naked DNA in solution.

transformation Signup and view all the answers

Feedback inhibition differs from repression because feedback inhibition

stops the action of preexisting enzymes. Signup and view all the answers

Bacteria can acquire antibiotic resistance by all of the following except

snRNPs. Signup and view all the answers

Suppose you inoculate three flasks of minimal salts broth with E. coli. Flask A contains glucose. Flask B contains glucose and lactose. Flask C contains lactose. After a few hours of incubation, you test the flasks for the presence of β-galactosidase. Which flask(s) do you predict will have this enzyme?

C Signup and view all the answers

Plasmids differ from transposons in that plasmids

are self-replicated outside the chromosome. Signup and view all the answers

Mechanism by which the presence of glucose inhibits the lac operon.

catabolite repression Signup and view all the answers

The mechanism by which lactose controls the lac operon.

induction Signup and view all the answers

Two offspring cells are most likely to inherit which one of the following from the parent cell?

a change in a nucleotide in DNA Signup and view all the answers

Which of the following is not a method of horizontal gene transfer?

binary fission Signup and view all the answers

Match the following examples of mutagens.

Frameshift mutagen = Nucleoside analog Nucleoside analog = Ionizing radiation Base-pair mutagen = Base-pair mutagen Ionizing radiation = Frameshift mutagen Signup and view all the answers

Match the following examples of mutagens.

<h1>A mutagen that causes the formation of pyrimidine dimers = Nonionizing radiation A mutagen that is incorporated into DNA in place of a normal base = Frameshift mutagen</h1> = Signup and view all the answers

When iron is not available, E. coli can stop synthesis of all proteins, such as superoxide dismutase and succinate dehydrogenase, that require iron. Describe a mechanism for this regulation.

Iron deficiency could stimulate miRNA that is complementary to RNA encoding iron-requiring proteins Signup and view all the answers

Why are mutation and recombination important in the process of natural selection and the evolution of organisms?

All of the above Signup and view all the answers

Restriction enzymes were first discovered with the observation that

phage DNA is destroyed in a host cell. Signup and view all the answers

The DNA probe, 3’-GGCTTA, will hybridize with which of the following?

5’-CCGAAT Signup and view all the answers

Which of the following is the fourth basic step to genetically modify a cell?

ligation Signup and view all the answers

The following enzymes are used to make cDNA. What is the second enzyme used to make cDNA?

ribozyme Signup and view all the answers

If you put a gene in a virus, the next step in genetic modification would be

transduction. Signup and view all the answers

You have a small gene that you want replicated by PCR. You add radioactively labeled nucleotides to the PCR thermal cycler. After three replication cycles, what percentage of the DNA single strands are radioactively labeled?

87.5% Signup and view all the answers

Pieces of human DNA stored in yeast cells.

library Signup and view all the answers

A population of cells carrying a desired plasmid.

clone Signup and view all the answers

Self-replicating DNA for transmitting a gene from one organism to another.

vector Signup and view all the answers

DNA that hybridizes with mRNA.

antisense Signup and view all the answers

Which are DNA?

cDNA = DNA gene = DNA DNA probe = DNA rDNA = DNA Signup and view all the answers

Of what value are sticky ends in making rDNA?

Fragments of DNA produced with the same restriction enzyme will spontaneously anneal to each other at their sticky ends Signup and view all the answers

Which of the following organisms are most closely related?

A and D Signup and view all the answers

Are any two the same species?

None of them are the same species Signup and view all the answers

Which of these organisms are most closely related?

A and D are most closely related. Signup and view all the answers

The GC content of Micrococcus is 66–75 moles %, and of Staphylococcus, 30–40 moles %. According to this information, would you conclude that these two genera are closely related?

No, they are not closely related Signup and view all the answers

Describe the use of a DNA probe and PCR for: Rapid identification of an unknown bacterium and determining which of a group of bacterium are most closely related.

DNA Probe = give us library of known bacteria to compare unknown bacteria to on plate PCR = allows for replication and isolation of one strand of DNA to match to DNA probe DNA Probe = allows us to match enzymes from sample to determine molecular % PCR = allows for replication and isolation of one strand of DNA to match to DNA probe Signup and view all the answers

Bergey’s Manual of Systematic Bacteriology differs from Bergey’s Manual of Determinative Bacteriology in that the former

groups bacteria according to phylogenetic relationships. Signup and view all the answers

Bacillus and Lactobacillus are not in the same order. This indicates that which one of the following is not sufficient to assign an organism to a taxon?

morphological characteristics Signup and view all the answers

Which of the following is used to classify organisms into the Kingdom Fungi?

absorptive; possess cell wall; eukaryotic Signup and view all the answers

You could identify an unknown bacterium by all of the following except

percentage of guanine + cytosine. Signup and view all the answers

The wall-less mycoplasmas are considered to be related to gram-positive bacteria . Which of the following would provide the most compelling evidence for this?

They share common rRNA sequences. Signup and view all the answers

Into which group would you place a multicellular organism that has a mouth and lives inside the human liver?

Animalia Signup and view all the answers

Into which group would you place a photosynthetic organism that lacks a nucleus and has a thin peptidoglycan wall surrounded by an outer membrane?

Proteobacteria (gram-negative bacteria) Signup and view all the answers

Which is (are) found in all three domains?

9 + 2 flagella

70S ribosome

fimbria

nucleus

peptidoglycan

plasma membrane

2,6 (70S ribosome and plasma membrane) Signup and view all the answers

Which is (are) found only in prokaryotes?

9 + 2 flagella

70S ribosome

fimbria

nucleus

peptidoglycan

plasma membrane

3, 5 (fimbria and peptidoglycan) Signup and view all the answers

If you Gram-stained the bacteria that live in the human intestine, you would expect to find mostly

gram-negative rods. Signup and view all the answers

Which of the following does not belong with the others?

Lactobacillales Signup and view all the answers

Pathogenic bacteria can be

All of the Above Signup and view all the answers

Which of the following is an intracellular parasite?

Rickettsia Signup and view all the answers

Which of the following terms is the most specific?

bacillus Signup and view all the answers

Which one of the following does not belong with the others?

Staphylococcus Signup and view all the answers

Which of the following pairs is mismatched?

spirochete—Helicobacter Signup and view all the answers

Spirillum is not classified as a spirochete because spirochetes

possess axial filaments. Signup and view all the answers

When Legionella was newly discovered, why was it classified with the pseudomonads?

It is an aerobic gram-negative rod. Signup and view all the answers

Unlike purple and green phototrophic bacteria, cyanobacteria

produce oxygen during photosynthesis. Signup and view all the answers

Use of culture-independent techniques such as rRNA sequencing and FISH have increased our understanding of microbial diversity without cultivation. Do microbiologists still need to attempt to grow new species? Briefly explain.

Yes, because there are many species yet to be discovered, mutations occur, exploration of new places leads to the possibility of new microbes Signup and view all the answers

To which of the following is the photosynthetic bacterium Chromatium most closely related? Briefly explain why.

Escherichia Signup and view all the answers

After contact with a patient’s spinal fluid, a lab technician developed fever, nausea, and purple lesions on her neck and extremities. A throat culture grew gram-negative diplococci. What is the genus of the bacteria?

Neisseria meningitidis Signup and view all the answers

Between April 1 and May 15 of one year, 22 children in three states developed diarrhea, fever, and vomiting. The children had each received pet ducklings. Gram-negative, facultatively anaerobic bacteria were isolated from both the patients’ and the ducks’ feces; the bacteria were identified as serovar C2. What is the genus of these bacteria?

Salmonella Signup and view all the answers

A woman complaining of lower abdominal pain with a temper-ature of 39°C gave birth soon after to a stillborn baby. Blood cultures from the infant revealed gram-positive rods. The woman had a history of eating unheated hot dogs during her pregnancy. Which organism is most likely involved?

Listeria Signup and view all the answers

Which of the following is NOT a characteristic of B cells?

They recognize antigens associated with MHC I. Signup and view all the answers

In the figure, which areas are similar for all IgG antibodies?

c and d Signup and view all the answers

Which of the following statements concerning immunological memory is true?

The memory response is due to production of long-lived memory cells that can respond very rapidly upon second exposure. Signup and view all the answers

What type of immunity results from vaccination?

artificially acquired active immunity Signup and view all the answers

What is the correct sequence of events for activation of a B cell by a T-dependent antigen?

(1) Immunoglobulin receptors on the B cell recognize and bind the antigen. (2) An antigen fragment in complex with MHC class 2 is displayed on the B cell's surface. (3) The MHC-antigen complex binds a receptor on a TH cell. (4) The TH cell secretes cytokines that activate the B cell. Signup and view all the answers

Which type of T cell is involved in activating macrophages and stimulating development of cytotoxic T cells?

TH1 cells Signup and view all the answers

Which of the following statements about cytokines is FALSE?

There are 10 types. Signup and view all the answers

Consider a helminthic infection in which an individual is colonized by a parasitic worm. The worm is too big to be engulfed by a phagocytic cell. How does the immune system respond?

The worm gets coated with antibodies, which activate other cells in the immune system to secrete chemicals that kill it. Signup and view all the answers

Which immunoglobulin class, found in blood, lymph, and the intestine, can cross the placenta and help to protect a fetus?

IgG Signup and view all the answers

When an antibody binds to a toxin, the resulting action is referred to as

neutralization Signup and view all the answers

Which of the following cells is NOT an APC?

natural killer cells Signup and view all the answers

In the figure, what portion will typically attach to a host cell?

e Signup and view all the answers

The antibodies found in mucus, saliva, and tears are

IgA. Signup and view all the answers

Which of the following statements concerning antigen-presenting cells is true?

They are involved in activating T cells. Signup and view all the answers

If a patient has been exposed to an antigen for the first time, which class of immunoglobulin appears first?

IgM Signup and view all the answers

Which of the following is the best definition of epitope?

specific regions on antigens that interact with antibodies Signup and view all the answers

The following events elicit an antibody response. What is the third step?

TH cell recognizes antigen-digest and MHC II. Signup and view all the answers

Newborns' immunity due to the transfer of antibodies across the placenta is an example of

naturally acquired passive immunity. Signup and view all the answers

Which of the following statements concerning cellular immunity is FALSE?

Cellular immunity involves cells that recognize antigens and make specific antibodies against them. Signup and view all the answers

A Treg cell deficiency could result in

autoimmunity. Signup and view all the answers

An individual may be exposed to a pathogen and become infected without actually getting sick. This is known as a subclinical infection. Even in subclinical infections, the individual's adaptive immune system can generate memory for the pathogen. What type of adaptive immunity is this?

naturally acquired active immunity Signup and view all the answers

Which of the following is NOT a characteristic of cellular immunity?

B cells make antibodies Signup and view all the answers

Which cytokines are believed to contribute to autoimmune disease, such as rheumatoid arthritis?

tumor necrosis factor (TNF) Signup and view all the answers

CD4+ T cells are activated by

interaction between CD4+ and MHC II. Signup and view all the answers

The following events occur in cellular immunity, leading to a response from TH cells. What is the third step?

TH cells proliferate. Signup and view all the answers

Which of the following terms regarding roles of chemical messengers is mismatched?

tumor necrosis factor - stimulate tumor metastasis Signup and view all the answers

What type of immunity results from recovery from mumps?

naturally acquired active immunity Signup and view all the answers

Which of the following statements about members of the Kingdom Plantae is FALSE?

They use organic carbon sources. Signup and view all the answers

A bacterial species differs from a species of eukaryotic organisms in that a bacterial species

is a population of cells with similar characteristics. Signup and view all the answers

Fatty acid methyl ester analysis is commonly used

in bacterial identification. Signup and view all the answers

In the table, which features are found in nearly all eukarya?

9+2 flagella

Nucleus

Plasma membrane

Peptidoglycan

Mitochondrion

Fimbriae

2, 3, 5 Signup and view all the answers

Phage typing is based on the fact that

bacterial viruses attack only members of a specific species. Signup and view all the answers

In a direct ELISA test, the method is determining if ________ is/are present in the patient's sample by attempting to bind a labeled antibody to it.

an antigen from a particular pathogen Signup and view all the answers

This figure shows the results of a gel electrophoresis separation of restriction fragments of the DNA of different organisms. In the figure, which two are most closely related?

1 and 3 Signup and view all the answers

Into which group would you place a photosynthetic cell that lacks a nucleus?

Bacteria Signup and view all the answers

Which of the following pairs is mismatched?

chemoautotrophic bacteria – fix atmospheric nitrogen Signup and view all the answers

You have isolated an aerobic gram-positive, endospore-forming bacterium that grows well on nutrient agar. To which of the following groups does it most likely belong?

bacillales Signup and view all the answers

Which of the following best describes the enterics, a bacterial group found primarily in the intestines of humans?

facultatively anaerobic gram-negative rods Signup and view all the answers

Which of the following is NOT a characteristic of spirochetes?

easily observed with brightfield microscopy Signup and view all the answers

The genus of bacteria that are particularly problematic in hospital settings due to their ability to grow in solutions with minute traces of unusual carbon sources is

Pseudomonas. Signup and view all the answers

Actinomycetes differ from fungi in that actinomycetes

lack a membrane-bounded nucleus. Signup and view all the answers

Staphylococcus and Streptococcus can usually be differentiated by microscope examination because of

cell arrangement. Signup and view all the answers

Assume you have isolated a multicellular heterotrophic organism that produces coenocytic hyphae, motile zoospores, and cellulose cell walls. It is most likely a(n)

oomycote alga. Signup and view all the answers

You observe a mass of amoeba-like cells that swarm together, form a stalk, and produce spores. This is a(n)

cellular slime mold. Signup and view all the answers

Which of the following is the most effective control for malaria?

eliminate Anopheles mosquitoes Signup and view all the answers

If a larva of Echinococcus granulosus is found in humans, humans are the

intermediate host. Signup and view all the answers

Which of the following statements regarding lichens is FALSE?

Lichens are a mutualistic relationship between a fungus and a protozoan. Signup and view all the answers

Which of the following pairs is mismatched?

anamorphs – lack spores Signup and view all the answers

A definitive host harbors which stage of a parasite?

adult Signup and view all the answers

Which of the following arthropods does NOT transmit diseases by sucking blood from a human host?

houseflies Signup and view all the answers

A feature that may be found in viruses but never in bacteria is

may contain an RNA genome. Signup and view all the answers

The most conclusive evidence that viruses cause cancers was provided by

cancer that developed in chickens following injection of cell-free filtrates. Signup and view all the answers

Which of the following is NOT utilized to culture viruses?

culture media Signup and view all the answers

What contributes to antigenic shift in influenza viruses?

a segmented genome Signup and view all the answers

The mechanism whereby an enveloped virus leaves a host cell is called

budding. Signup and view all the answers

What is NOT true regarding viruses that infect plants?

They are often cultured in embryonated chicken eggs. Signup and view all the answers

Which of the following is necessary for replication of a prion?

PrPSc Signup and view all the answers

When monocytes leave circulating blood and enter body tissues, they mature into:

Macrophages Signup and view all the answers

In the classical pathway of complement activation, C2a binds:

C4b Signup and view all the answers

Opsonization of enhances phagocytosis; membrane attack Complex is made up of .

C3b; made up of C5b, C6, C7, C8, and C9. Signup and view all the answers

List the effects of IFN gamma

All of the Above Signup and view all the answers

List the steps in order of phagocytosis

<ol> <li>Chemotaxis and adherence</li> <li>Ingestion</li> <li>Phagosome formation</li> <li>Phagolysosome formation</li> <li>Digestion</li> <li>Residual body formation</li> <li>Discharge</li> </ol> Signup and view all the answers

What portion of the T cells can recognize an antigenic peptide?

T-cell receptors (TCRs) Signup and view all the answers

When an antibody binds attachment points of a toxin, bacteria or virus is called:

Neutralization Signup and view all the answers

Type of T cell that stimulates production of eosinophils, IgM and IgE

T-helper 2 (TH2) cell Signup and view all the answers

A recent survivor of Ebola virus donates their plasma (containing antibodies) to a current family member and patient with Ebola. This hopefully results in which type of immunity for the current patient?

artificially acquired passive immunity. Signup and view all the answers

Which are components of an antibody?

All of the Above Signup and view all the answers

Following is a list of fungi, their methods of entry into the body, and sites of infections they cause. Categorize each type of mycosis as cutaneous, opportunistic, subcutaneous, superficial, or systemic.

Blastomyces = Systemic Sporothrix = Subcutaneous Microsporum = Cutaneous Trichosporon = Superficial Signup and view all the answers

A mixed culture of Escherichia coli and Penicillium chrysogenum is inoculated onto the following culture media. On which medium would you expect each to grow?

<h1>0.5% peptone in tap water = E. coli 10% glucose in tap water = P. chrysogenum</h1> = Signup and view all the answers

Briefly discuss the importance of lichens in nature.

lichens are responsible for the chemical weathering of large inorganic particles and the consequent accumulation of soil. Signup and view all the answers

Briefly discuss the importance of algae in nature.

Algae are primary producers in aquatic food chains and are important oxygen-producers. Signup and view all the answers

Why is it significant that Trichomonas does not have a cyst stage?

Trichomonas cannot survive for long outside a host because it does not form a protective cyst. Signup and view all the answers

By what means are helminthic parasites transmitted to humans?

Ingestion Signup and view all the answers

Most roundworms are dioecious. What does this term mean

The male reproductive organs are in one individual, and the female reproductive organs in another. Signup and view all the answers

How many phyla are represented in the following list of organisms: Echinococcus, Cyclospora, Aspergillus, Taenia, Toxoplasma, Trichinella?

4 Signup and view all the answers

Put the above stages in order of development, beginning with the egg.

metacercaria

redia

adult

miracidium 5.cercaria

4, 2, 5, 1, 3 Signup and view all the answers

If a snail is the first intermediate host of a parasite with these stages, which stage would be found in the snail?

metacercaria

redia

adult

miracidium 5.cercaria

2 Signup and view all the answers

Fleas are the intermediate host for Dipylidium caninum tapeworm, and dogs are the definitive host. Which stage of the parasite could be found in the flea?

cysticercus larva Signup and view all the answers

Which of the following statements about yeasts are true?

Yeasts are fungi.

Yeasts can form pseudohyphae.

Yeasts reproduce asexually by budding.

Yeasts are facultatively anaerobic.

All yeasts are pathogenic.

All yeasts are dimorphic.

1, 2, 3, 4 Signup and view all the answers

Which of the following events follows cell fusion in an ascomycete?

ascospore formation Signup and view all the answers

The definitive host for Plasmodium vivax

Anopheles. Signup and view all the answers

These are obligate intracellular parasites that lack mitochondria.

Microsporidia Signup and view all the answers

These are nonmotile parasites with special organelles for penetrating host tissue.

Apicomplexa Signup and view all the answers

These photosynthetic organisms can cause paralytic shellfish poisoning.

dinoflagellates Signup and view all the answers

Why are freshwater fish more likely to be a source of tapeworm infection than marine fish?

tapeworms better survive in a freshwater environment than a saltwater environment. Signup and view all the answers

Why do we classify viruses as obligatory intracellular parasites?

Viruses absolutely require living host cells to multiply. Signup and view all the answers

List the four properties that define a virus.

contains DNA or RNA;has a protein coat surrounding the nucleic acid;multiplies inside a living cell using the synthetic machinery of the cell;causes the synthesis of virions. Signup and view all the answers

What is a virion?

a fully developed virus particle that transfers the viral nucleic acid to another cell and initiates multiplication. Signup and view all the answers

Compare biosynthesis of a + stranded RNA and a − stranded RNA virus.

Both produce double-stranded RNA, with the - strand being the template for more + strands. + strands act as mRNA in both virus groups. Signup and view all the answers

Some antibiotics activate phage genes. MRSA releasing Panton-Valentine leukocidin causes a life-threatening disease. Why can this happen following antibiotic treatment?

Antibiotic treatment of S. aureus can activate phage genes that encode P-V leukocidin. Signup and view all the answers

Koch’s postulates are used to determine the etiology of a disease. Why is it difficult to determine the etiology of a viral infection, such as influenza?

Viruses cannot easily be observed in host tissues. Viruses cannot easily be cultured in order to be inoculated into a new host. Additionally, viruses are specific for their hosts and cells, making it difficult to substitute a laboratory animal for the third step of Koch’s postulates. Signup and view all the answers

Koch’s postulates are used to determine the etiology of a disease. Why is it difficult to determine the etiology of cancer?

Some viruses can infect cells without inducing cancer. Cancer may not develop until long after infection. Cancers do not seem to be contagious. Signup and view all the answers

Persistent viral infections such as (a) _____ might be caused by (b) _ that are (c ) _______.

<h1>subacute sclerosing panencephalitis = a common viruses = b latent, in an abnormal tissue. = c</h1> Signup and view all the answers

Plant viruses can’t penetrate intact plant cells because (a) _____; therefore, they enter cells by (b) _. Plant viruses can be cultured in (c) _______.

<h1>of the rigid cell walls = a vectors such as sap-sucking insects = b plant protoplasts and insect cell cultures = c</h1> Signup and view all the answers

Discuss the arguments for and against the classification of viruses as living organisms.

They can be considered living because they contain DNA and/or RNA. However, they can be considered nonliving because they require a host organism to activate biochemical processes. Signup and view all the answers

Why was the discovery of simian AIDS and feline AIDS important?

Simians and felines are ideal models for testing the pathogenicity of SIV and FIV mutants, and possibly provide some insight into HIV and the evolution of retroviruses as well. Signup and view all the answers

Place the following in the most likely order for biosynthesis of a bacteriophage: (1) phage lysozyme; (2) mRNA; (3) DNA; (4) viral proteins; (5) DNA polymerase.

2, 5, 3, 4, 1 Signup and view all the answers

The molecule serving as mRNA can be incorporated in the newly synthesized virus capsids of all of the following except

<ul> <li>strand RNA rhabdoviruses.</li> </ul> Signup and view all the answers

A virus with RNA-dependent RNA polymerase

synthesizes double-stranded RNA from an RNA template. Signup and view all the answers

Which of the following would be the first step in the biosynthesis of a virus with reverse transcriptase?

A complementary strand of RNA must be synthesized. Signup and view all the answers

An example of lysogeny in animals could be

latent viral infections. Signup and view all the answers

The ability of a virus to infect an organism is regulated by

all of the above Signup and view all the answers

Which of the following statements is false?

Viruses multiply inside living cells using viral mRNA, tRNA, and ribosomes. Signup and view all the answers

Place the following in the order in which they are found in a host cell: (1) capsid proteins; (2) infective phage particles; (3) phage nucleic acid.

3, 1, 2 Signup and view all the answers

Which of the following does not initiate DNA synthesis?

a single-stranded RNA virus (Togaviridae) Signup and view all the answers

A viral species is not defined on the basis of the disease symptoms it causes. The best example of this is

hepatitis. Signup and view all the answers

Cancer patients undergoing chemotherapy are normally more susceptible to infections. However, a patient receiving an antitumor drug that affects eukaryotic cytoskeletons was resistant to Salmonella. Provide a possible mechanism for the resistance.

Salmonella affects host cells by disrupting the plasma membrane with invasins; it then uses the host's cytoskeleton to cause further damage in the cell; the drug could disrupt one of these processes, or it could simply inhibit the division of salmonella cells Signup and view all the answers

The ability of a microorganism to produce a disease is called pathogenicity. The degree of pathogenicity is virulence. Signup and view all the answers

How are capsules and cell wall components related to pathogenicity?

Encapsulated bacteria can resist phagocytosis and continue growing. Signup and view all the answers

Explain how drugs that bind each of the following would affect pathogenicity: iron in the host’s blood

Would inhibit bacteria. Signup and view all the answers

Explain how drugs that bind each of the following would affect pathogenicity: Neisseria gonorrhoeae fimbriae

Would prevent adherence of N. gonorrhoeae. Signup and view all the answers

Explain how drugs that bind each of the following would affect pathogenicity: Streptococcus pyogenes M protein

S. pyogenes would not be able to attach to host cells and would be more susceptible to phagocytosis. Signup and view all the answers

How can viruses and protozoa avoid being killed by the host’s immune response?

All of the Above Signup and view all the answers

The removal of plasmids reduces virulence in which of the following organisms?

Streptococcus mutans Signup and view all the answers

What is the LD50 for the bacterial toxin tested in the example below?

c Signup and view all the answers

Which of the following is not a portal of entry for pathogens?

blood Signup and view all the answers

All of the following can occur during bacterial infection. Which would prevent all of the others?

vaccination against fimbriae Signup and view all the answers

The ID50 for Campylobacter sp. is 500 cells; the ID50 for Cryptosporidium sp. is 100 cells. Which of the following statements is false?

Cryptosporidium is more virulent than Campylobacter. Signup and view all the answers

An encapsulated bacterium can be virulent because the capsule

resists phagocytosis. Signup and view all the answers

A drug that binds to mannose on human cells would prevent

the attachment of pathogenic E. coli. Signup and view all the answers

The earliest smallpox vaccines were infected tissue rubbed into the skin of a healthy person. The recipient of such a vaccine usually developed a mild case of smallpox, recovered, and was immune thereafter. What is the most likely reason this vaccine did not kill more people?

Skin is the wrong portal of entry for smallpox. Signup and view all the answers

Which of the following does not represent the same mechanism for avoiding host defenses as the others?

Surface protein genes in Neisseria gonorrhoeae mutate frequently. Signup and view all the answers

Which of the following statements is true?

A successful pathogen doesn’t kill its host before it is transmitted. Signup and view all the answers

Identify at least one physical factor and one chemical factor that prevent microbes from entering the body through each of the following: urinary tract

Physical: movement out; Chemical: lysozome; acids Signup and view all the answers

Identify at least one physical factor and one chemical factor that prevent microbes from entering the body through each of the following:reproductive tract

Physical: movement out; Chemical: acidic environment in female Signup and view all the answers

Define inflammation, and list its characteristics.

All of the Above Signup and view all the answers

What are interferons?

Interferons are defensive proteins. Signup and view all the answers

Patients with X-linked chronic granulomatous disease are susceptible to infections because their neutrophils don’t generate an oxidative burst. What is the relation of the oxidative burst to infection?

Toxic oxygen products can kill pathogens. Signup and view all the answers

Why does hemolysis of red blood cells occur when a person receives a transfusion of the wrong type of blood?

None of the Above Signup and view all the answers

Give examples of how microbes evade the complement system.

All of the Above Signup and view all the answers

Are the following involved in innate or in adaptive immunity? Identify the role of each in immunity:

<h1>TLRs = Innate. Facilitate adherence of phagocyte and pathogen. transferrins = Innate. Bind iron. antimicrobial peptides = Innate. Kill or inhibit bacteria.</h1> Signup and view all the answers

What role does transferrin play in fighting an infection?

They transport and store iron Signup and view all the answers

Leukocyte adherence deficiency (LAD) is an inherited disease resulting in the inability of neutrophils to recognize C3b-bound microorganisms. What are the most likely consequences of LAD?

LAD leukocytes can't recognize opsonized Microorganisms, which delays the elimination of the microorganism by innate response and increases the susceptibility to infection Signup and view all the answers

The neutrophils of individuals with Chédiak-Higashi syndrome (CHS) have fewer than normal chemotactic receptors and lysosomes that spontaneously rupture. What are the consequences of CHS?

All of the Above Signup and view all the answers

Legionella uses C3b receptors to enter monocytes. This...

prevents phagocytosis. Signup and view all the answers

Chlamydia can prevent the formation of phagolysosomes and therefore can

avoid being digested. Signup and view all the answers

If the following are placed in the order of occurrence, which would be the third step?

formation of a phagosome Signup and view all the answers

If the following are placed in the order of occurrence, which would be the third step?

activation of C3 Signup and view all the answers

A human host can prevent a pathogen from getting enough iron by all of the following except

binding iron with siderophores. Signup and view all the answers

A decrease in the production of C3 would result in

increased susceptibility to infection. Signup and view all the answers

In 1884, Elie Metchnikoff observed cells collected around a splinter inserted in a sea star embryo. This was the discovery of

phagocytosis. Signup and view all the answers

Helicobacter pylori uses the enzyme urease to counteract a chemical defense in the human organ in which it lives. This chemical defense is

hydrochloric acid. Signup and view all the answers

Which of the following statements about IFN-α is false?

It is virus-specific. Signup and view all the answers

Which of the following does not stimulate phagocytes?

histamine Signup and view all the answers

What does MHC stand for?

The major histocompatability complex Signup and view all the answers

What is the function of MHC?

self-antigens Signup and view all the answers

What types of T cells interact with MHC class I? With MHC class II?

CTL cells react with MHC I and TH cells react with MHC II. Signup and view all the answers

Explain a function for the following types of cells: CTL, TH, and Treg.

CTLs destroy target cells on contact. TH cells interact with an antigen to “present” it to a B cell for antibody formation. TR cells suppress the immune response. Signup and view all the answers

What is a cytokine?

Cytokines are chemicals released by cells that initiate a response by other cells. Signup and view all the answers

How would each of the following prevent infection? antibodies against Neisseria gonorrhoeae fimbriae

prevent attachment of the pathogen by interfere with the attachment site on the pathogen Signup and view all the answers

prevent attachment of the pathogen; (a) interfere with the attachment site on the pathogen antibodies against host cell mannose

prevent attachment of the pathogen by interfere with the pathogen’s receptor site. Signup and view all the answers

How can a human make over 10 billion different antibodies with only 25,000 different genes?

Rearrangement of the V region genes during embryonic development produces B cells with different antibody genes. Signup and view all the answers

Explain why a person who recovers from a disease can attend others with the disease without fear of contracting it.

The person recovered because he or she produced antibodies against the pathogen. The memory response will continue to protect the person against that pathogen. Signup and view all the answers

The type of protection provided by the injection of diphtheria toxoid.

artificially acquired active immunity Signup and view all the answers

The type of protection provided by the injection of antirabies serum.

artificially acquired passive immunity Signup and view all the answers

The type of protection resulting from recovery from an infection.

naturally acquired active immunity Signup and view all the answers

A newborn’s immunity to yellow fever.

naturally acquired passive immunity Signup and view all the answers

Antibodies that protect the fetus and newborn.

IgG Signup and view all the answers

The first antibodies synthesized; especially effective against microorganisms.

IgM Signup and view all the answers

Antibodies that are bound to mast cells and involved in allergic reactions.

IgE Signup and view all the answers

Put the following in the correct sequence to elicit an antibody response: (1) TH cell recognizes B cell; (2) APC contacts antigen; (3) antigen fragment goes to surface of APC; (4) TH recognizes antigen digest and MHC; (5) B cell proliferates.

2, 3, 4, 1, 5 Signup and view all the answers

A kidney-transplant patient experienced a cytotoxic rejection of his new kidney. Place the following in order for that rejection: (1) apoptosis occurs; (2) CD8+ T cell becomes CTL; (3) granzymes released; (4) MHC class I activates CD8+ T cell; (5) perforin released.

4, 2, 5, 3, 1 Signup and view all the answers

Patients with Chédiak-Higashi syndrome suffer from various types of cancer. These patients are most likely lacking which of the following?

NK cells Signup and view all the answers

Where are heterocysts found?

nitrogen-fixing cyanobacteria Signup and view all the answers

Into which field of microbiology would the following scientists best fit:Studies biodegradation of toxic wastes

Biotechnology and Microbial Ecology Signup and view all the answers

Into which field of microbiology would the following scientists best fit?:Studies the causative agent of Ebola virus disease

Virology Signup and view all the answers

Into which field of microbiology would the following scientists best fit?: Studies the production of human proteins by bacteria

Biotechnology and Microbial Genetics and Microbial Physiology Signup and view all the answers

Into which field of microbiology would the following scientists best fit?: Studies the symptoms of AIDS

Immunology Signup and view all the answers

Into which field of microbiology would the following scientists best fit:Studies biodegradation of pollutants

Microbial ecology Signup and view all the answers

Into which field of microbiology would the following scientists best fit: Develops gene therapy for a disease

Molecular biology Signup and view all the answers

Into which field of microbiology would the following scientists best fit: Studies the fungus Candida albicans

Mycology Signup and view all the answers

which field of microbiology would the following scientists best fit Into: Studies the production of toxin by E. coli

Microbial Physiology Signup and view all the answers

Who discovered penicillin

Fleming Signup and view all the answers

Who first observed cells in plants

Hooke Signup and view all the answers

Who proved that microorganisms can cause disease?

Koch Signup and view all the answers

Who disproved spontaneous generation?

Pasteur Signup and view all the answers

What is saccharomyces?

Yeast sold for making bread, wine and beer Signup and view all the answers

What is baccillius thuringiensis?

Biological insecticide Signup and view all the answers

Which are associated with Gram stains

All of the Above Signup and view all the answers

Final Exam!

Choose a study mode

Podcast

Questions and Answers

Which stain (from a list) would be helpful in determining the size and shape of a colorless bacterium WITHOUT fixing.

In a Gram stain, a step could be ommitted and still alllow differentiation between Gram positive and Gram negative cells. Which step?

Which is NOT a type of inclusion (from a list)?

How can genomes from microbes that cannot be grown in the lab still be studied?

Six Staphylococcus aureus cells were accidently inoculated into an uncooked pie. How many cells would be in the pie after 3 hours. Assume generation time of 60 minutes.

If an F+, Cys+ cell recombines with an F-, Cys- cell, what might happen to the F-,Cys- cell?

During PCR, instead of using DNA polymerase from Thermus aquaticus, human DNA polymerase is used. Starting with 1 molecule of DNA, after 3 full cycles are completed (assuming all other conditions remain the same), how many DNA molecules do you expect to see?

How did the idea of spontaneous generation come about?

What role do microorganisms play in the biological control of pests?

What is the role do microorganisms play in recycling elements?

What role do microorganisms play in normal microbiota?

What role do microorganisms play in sewage treatment?

What role do microorganisms play in human insulin production?

What role does microorganisms play in vaccine production?

What role do microorganisms play in biofilms?

Match the microorganisms in column A to their descriptions in column B.

Match the microorganisms in column A to their descriptions in column B.

What type of microorganism has a peptidoglycan cell wall, has DNA that is not contained in a nucleus, and has flagella?

Where airborne microbes ended up in Pasteur’s experiment?

Which of the following is a scientific name?

Which of the following is not a characteristic of bacteria?

Which of the following is the most important element of Koch’s germ theory of disease? The animal shows disease symptoms when

Recombinant DNA is

Which of the following statements is the best definition of biogenesis?

Which of the following is a beneficial activity of microorganisms?

It has been said that bacteria are essential for the existence of life on Earth. Which of the following is the essential function performed by bacteria?

Which of the following is an example of bioremediation?

Spallanzani’s conclusion about spontaneous generation was challenged because Antoine Lavoisier had just shown that oxygen was the vital component of air. Which of the following statements is true?

Which of the following statements about E. coli is false?

How did the theory of biogenesis lead the way for the germ theory of disease?

Even though the germ theory of disease was not demonstrated until 1876, why did Semmelweis (1840) and Lister (1867) argue for the use of aseptic techniques?

Should antibacterial soaps and detergents be used in the home?

Which is NOT an emerging pathogen as described in your text.

Recombinant DNA technology has become an increasingly important part of our life. It is used for all of the following EXCEPT

Development of emerging infectious disease can be a result of all of the following EXCEPT

Which of the following is the best definition of oxidative phosphorylation?

In the figure, where is ATP produced?

Which of the following statements is INCORRECT regarding prokaryotic cells?

Which of the following statements regarding metabolism is FALSE?

Which of the following pairs is mismatched?

All of the below are examples of a biofilm EXCEPT

In non-cyclic photophosphorylation, excited electrons ultimately

Functions of the glycocalyx include all of the following EXCEPT

A microorganism measures 5 μm in length. What is its length in mm, nm, and m?

Which type of microscope would be best to use to observe a stained bacterial smear

Which type of microscope would be best to use to observe unstained bacterial cells: the cells are small, and no detail is needed

Which type of microscope would be best to use to observe unstained live tissue when it is desirable to see some intracellular detail?

Which type of microscope would be best to use to observe a sample that emits light when illuminated with ultraviolet light?

Which type of microscope would be best to use to observe intracellular detail of a cell that is 1 μm long?

Which type of microscope would be best to use to observe unstained live cells in which intracellular structures are shown in color?

Label the parts of the compound light microscope in the figure below, and then draw the path of light from the illuminator to your eye.

Calculate the total magnification of the nucleus of a cell being observed through a compound light microscope with a 10× ocular lens and an oil

The maximum magnification of a compound microscope is

The maximum magnification of an electron microscope

The maximum resolution of a compound microscope is

The maximum resolution of an electron microscope

One advantage of a scanning electron microscope over a transmission electron microscope is

In a hypertonic solution, what is likely to happen to a protoplast?

What is the fate of pyruvic acid in an organism that uses aerobic respiration?

An enzyme, citrate synthase, is inhibited by ATP. This is an example of:

Given a "recipe" for a specific culture medium, identify a complex or defined medium.

Which of the following disinfectants from a given list acts by disrupting the plasma membrane?

Which chemical method of microbial control damage DNA?

Repeating sequences of non-coding DNA that are used for forensic analysis is called

If tryptophan is present, the repressible operon is:

What are key features of a restriction enzyme?

How is cDNA made?

Why is a mordant used in the Gram stain?

Why is a mordant used in the flagella stain?

What is the purpose of a counterstain in the acid-fast stain?

What is the purpose of a decolorizer in the Gram stain?

What is the purpose of a decolorizer in the acid-fast stain?

Assume you stain Bacillus by applying malachite green with heat and then counterstain with safranin. Through the microscope, the green structures are

Three-dimensional images of live cells can be produced with

Carbolfuchsin can be used as a simple stain and a negative stain. As a simple stain, the pH is

Looking at the cell of a photosynthetic microorganism, you observe the chloroplasts are green in brightfield microscopy and red in fluorescence microscopy. You conclude:

Which statements correspond to amphibolic pathways?

Anabolic and catabolic reactions are joined through common intermediate.

They are shared metabolic pathways.

Feedback inhibition can help regulate rates of reactions.

Both types of reactions are necessary but do not occur simultaneously.