Microbiology Exam 3 CH 10&11, 12, 13

Which phylum of Protozoa contains organisms that are non-mobile, obligate intracellular parasites.

Apicomplexa

Biochemical tests ____________.

Are the main methods used to identify unknown bacteria.

Coccidioides immitis is a pathogenic fungus that forms asexual spores called _____________, which result from fragmentation of hyphae.

Arthroconidia

Based on the lab results, which organism is most likely causing Tori's new symptoms? (When the Bacteria Are Away, the Fungi Will Play CH 12)

Candida albicans

Of the following food products, which one was most likely the source of Mr. Williams infection? (When the Cows come home CH 10/11)

Raw milk

Which of the following are the main causative agents of the common cold?

Rhinoviruses and coronaviruses

Which disease did Stanley Prusiner first identify as being caused by prions?

Scrapie

Which of the following pathogenic characteristics would best allow Brucella organisms to produce a chronic infection in a host? (When the Cows Come Home CH 10/11)

Sequestering of an organism within the endoplasmic reticulum.

What are Algae?

-Members of this group are found predominantly in aquatic environments. -Members of this group generally don't cause infections, but some produce neurotoxins that cause intoxications in animals that consume them.

Lysogenic viral DNA which has integrated into the host genome is referred to as?

A prophage

Which virus is not associated with cancer?

Coronavirus

The term dermatophyte is typically used for fungi that cause which of the following?

Cutaneous mycoses

How does the number of infectious prions increase?

Prions transform normal proteins into the misfolded beta-pleated sheet configuration; therefore, prions multiply by conversion.

Humans are the definitive host for __________. Which is a type of _____________.

Tania saginala, tapeworm

Which of the following statements concerning viruses is true?

The "host range" for a virus is determined by the presence or absence of particular components on the surface of a host cell that are required for the virus to attach.

Which of the following best explains why Tori developed a new series of symptoms? (When the Bacteria Are Away, the Fungi Will Play CH 12)

The antibiotics that treated Tori's primary respiratory infection also removed some of her normal bacteria flora, resulting in an overgrowth of other organisms.

What part of nervous system is most affected by fatal familial insomnia?

thalamus

Select the eukaryotic organisms that are involved in causing or spreading disease:

-fungus -alga -protozoan -helminth -arthropod

Some fungi reproduce sexually by forming __________, which are sexual spores contained within a sac structure.

Ascospores

In which stage does formation of mature viruses occur?

Assembly

The normal function of the PrP protein in mammals is believed to be?

Assisting in normal synaptic development and function.

What are some characteristics of Eukaryotes only?

-80S ribosomes -membranous organelles, including mitochondria, lysosomes, endoplasmic reticulum -nuclear envelope compartmentalizes the chromosomes

What are the implications of the attachment process?

-A particular virus may be able to infect a liver cell but not a lung cell. -Some people are naturally (innately) resistant to certain viral infections. -Viral infection of a cell may be prevented by blocking the attachment sites on a virus with antibody. -Viral infection of a cell may be prevented by blocking the receptor sites on a host cell. -A particular virus may be able to infect humans but not mice.

Which of the following could Tori's physician choose as a treatment for her yeast infection? (When the Bacteria Are Away, the Fungi Will Play CH 12)

-A single oral dose of fluconazole -A topical over-the-counter ointment, such as clotrimazole or miconazole.

Domain Bacteria consists of?

-Cyanobacteria -Gram-positive bacteria -Proteobacteria -Mitochondria -Thermotoga -Chloroplasts

What are the characteristics of Helminths?

-Either eggs or larval stages of Helminths may be infectious, depending on the species. -Humans can serve as either definitive or intermediate hosts of flatworms. -The major organ system apparent in tapeworm proglottids is the reproductive system. -Parasitic Helminths lack a complete digestive system and they absorb nutrients directly through their cuticles. -Some Helminth infections involve more than one intermediate host.

Domain Archaea consist of?

-Extreme Halophiles -Hyperthermophiles -Methanogens

Which of the following infections are also caused by C. albicans? (When the Bacteria Are Away, the Fungi Will Play CH 12)

-Fulminating disease -Oral thrush

Domain Eukarya consists of?

-Fungi -Slime Molds -Ciliates -Green Algae -Plants -Amebae -Animals -Diatoms -Giardia -Euglenozoa -Dinoflagellates

Which of the following factors could have contributed to Barbara's development of shingles? (What Does Old Age have to Do with It? CH 13)

-Her daughter and grandchildren moving into her house shortly after the death of her husband. -Her age, 68

Select strategies that are likely to interfere with viral infection and replication but will NOT damage the normal functioning of host cells.

-Inhibiting viral assembly and maturation processes -Inhibiting viral -encoding DNA polymerase -Inhibiting the release of viruses from the host cell -Blocking attachment sites on the virus surface -Blocking host cell receptors that serve as sites for viruses to attach

What are Protozoa?

-Many members of this group are mobile by means of cilia, flagella, or pseudopods. -Members of this group cause malaria and diarrheal illnesses such as amebiasis and giardiasis.

Which of the following is NOT a sign or symptom of the common cold?

Diarreah

What are Helminths?

-Members of this group come in flat or round forms, and although many parasitize animals, there are also free-living forms. -Parasitic members of this group often have complex life cycles involving one or more intermediate hosts in which larvae develop.

What are Fungi?

-Members of this group produce a variety of different reproductive spores and filaments referred to as hyphae. -This group includes unicellular as well as filamentous forms, a number of which cause infections.

What are Arthropods?

-Members of this group serve as vectors, transmitting several different viruses, bacteria, and protozoan parasites between hosts. -Members of this group have hard exoskeletons and jointed appendages.

What are the characteristics of Protozoa?

-Most Protozoa are mobile via pseudopods, flagella, cilia, or undulating membranes. -While living in the gut of their host, intestinal protozoan parasites are usually in the trophozoite form. -As a group, Protozoa exhibit both asexual and sexual reproduction. -Protozoa cysts enable protozoan parasites to survive during passage from one host to the net.

What are the characteristics of algae?

-Most algae have a plant-like cell wall composed of cellulose. -Algae may be green, red, or brown. -Algae lack roots, stems, leaves, and vascular tissue that are found n terrestrial plants. -Some marine algae produce neurotoxis that can be concentrated in shellfish and pose a risk of paralytic shellfish poisoning to humans who consume the shellfish. -Both asexual and sexual reproduction occurs among the diversity of algal species.

Which of the following types of molecules are found in all viruses?

-Proteins -Nucleic acids

What are some characteristics of Prokaryotes only?

-binary fission -cell wall contains peptidoglycan or pseudomurien -70S ribosomes -singular circular chromosome.

What are characteristics that both Prokaryotes and Eukaryotes both have?

-includes unicellular cells -has both DN and RNA -plasma membrane encloses the cytoplasm

What are the steps of the reproductive cycle of a virus that causes the common cold?

1. Binding to protein receptors on cell surface. 2. Release of nucleic acid from capsid. 3. Transcription and translation. 4. Capsid assembly. 5. Release of virus from cell.

What is the correct sequence of events for the replication of a DNA virus?

1. Virus attach to the host cells. 2. Viral DNA is released into the nucleus of the host cell. 3. Enzymes required for multiplication of viral DNA are produced via transcription and translation. 4. A copy of the DNA is made. 5. Capsid and other structural proteins are manufactured. Virions are assembled to form complete viruses and are released from the host cell.

In what year did Stanley Prusiner discover prions?

1982

The first cells were formed approximately _____________ years ago.

3 billion

Why is visualization not sufficient to properly identify bacteria?

Bacteria have a limited set of shapes and many unrelated bacteria share the same shapes.

Sexual spores known as _____________ are located on a base pedestal and are found in mushrooms.

Basidiospores

The host DNA is usually degraded during which stage?

Biosynthesis

How do blastocondidia and chlamydoconidia produced by yeast differ from bacterial endospores? (When the Bacteria Are Away, the Fungi Will Play CH 12)

Blastocondidia and chlamydoconidia are spore structures produced by budding in yeasts, whereas bacterial endospores are produced by bacteria under extreme conditions.

Asexual spores that form as buds coming off the parent cell are known as ____________and are produced by yeasts such as Candida albicans and Cryptococcus neoformans.

Blastoconidia

Why are doxycycline and rifampin ideal agents for treating intracellular pathogens such as Brucella and Mycobacteria? (When the Cows Come Home CH 10/11)

Both agents provide for good penetration of body tissues and reach therapeutic levels.

Which of the following Brucella species is most likely indicated in this case? (When the Cows Come Home CH 10/11)

Brucella abortus

Candida albicans, a species of pathogenic yeast, is often recognized by its ___________ which are large, thick-walled asexual spores within a hyphae segment.

Chlamydoconidia

Which of the following prion diseases is found in deer and elk?

Chronic wasting disease

Which of the following is true regarding cultivation and isolation of animal viruses?

Diploid cell culture lines, developed from human embryos, are widely used for culturing viruses that require a human host.

What does Dr. Johnson order a PPD for Mr. Williams? (When the Cows Come Home CH 10/11)

He wants to rule out the possibility of bovine tuberculosis.

Which statement regarding helminths is true?

Helminths usually possess specialized organ systems, including circulatory, nervous, and reproductive systems.

A unicellular, photosynthetic nucleated cell would belong to which domain?

Eukarya

Which of the following events might trigger induction of a temperature bacteriophages?

Exposure to UV light

Each of the following can be used for the detection and/or identification of viruses except?

Fermentation tests

Which of the following statements best describes why the treatment for Tori's fungal infection may result in side effects to her own cells? (When the Bacteria Are Away, the Fungi Will Play CH 12)

Fungal cells and human cells have a nucleus, multiple organelles, and 80S ribosomes for protein synthesis.

The first question in the dichotomous key addresses?

Gram stain differences

Trichomonas vaginalis can be distinguished from other parasitic Protozoa by which of the characteristics listed below?

It has an undulating membrane, infects the vagina, and is frequently transmitted by sexual contact.

What is the fate of the prophage during the lysogenic stage?

It is copied every time the host DNA replicates.

Which of the following statements regarding latent viral infections is true?

Latent infections can persist for years in an individual without causing any symptoms.

Dengue fever and Zika virus are transmitted by which of the following?

Mosquitoes

Using a mouse model, the investigator orally inoculates mice with a mutated strain of Brucella lacking the gene for production of urease. Indicate which of the following would least support the hypothesis that urease plays a role as a virulence factor in establishing Brucella infection. (When the Cows Come Home CH 10/11)

Mutant and non-mutant strains will demonstrate the ability to transition through intestinal mucosa.

Barbara is worried about spending time with her grandchildren while being treated for shingles. Can her grandchildren contract chickenpox or shingles from spending time with their grandmother? (What Does Old Age have to Do with It? CH 13)

No. Because of their ages, the grandchildren have most likely been vaccinated against the chickenpox. They are also safe from contracting shingles because they are young.

How do normal prion proteins (PrP) differ from the infectious prion proteins?

Normal PrP have alpha-helices; infectious PrP have beta-pleated sheets.

In which stage is the viral DNA introduced into the cell?

Penetration

Which of the following organisms requires an additional non-human host to complete its life cycle?

Plasmodium species

From which phrase is the term "prions" derived?

Proteinaceous infectious particles

Which of the following best describes Barbara's condition? (What Does Old Age have to Do with It? CH 13)

Shingles caused by the herpes zoster virus

Which statement concerning viral structure is true?

Spikes are found on some viruses. They are very consistent in structure and can be used for identification.

Rhizopus stolonifer, the common black bread mold, forms asexual spores called _________, which are contained in a sac at the end of aerial hyphae.

Sporangiospores

What is the function of the structural elements of a virus?

To package and protect the viral genome

What happens to the packaged DNA of a specialized transduced phage when it infects a new recipient cell?

The host DNA integrates, with the prophage, into the new recipient chromosome.

How is the lyric cycle different from the lysogenic cycle with respect to the infected host cell?

The host cell dies during the lytic stage.

Why are the beta-pleated multimers of PrP potentially pathogenic?

The multimers are more stable and resistant to protease.

Where does the name "scrapie" come from?

The prion disorder causes infected sheep to scrape against objects until their skin is raw.

How does specialized transduction differ from regular lysogeny?

The prophage in specialized transduction carries with it pieces of the host chromosomal DNA.

How can specialized transduction contribute to the transfer of antibiotic resistance genes in a bacterial population?

The prophage takes an antibiotic resistance gene with it and is packaged with the newly synthesized viral DNA.

What would be the fate of a lyric bacteriophage if the host cell died prior to the assembly stage?

The virus would not be able to infect new hosts.

Protozoa sample?

These were observed in a duodenal specimen from a patient with diarrhea. They mov actively by using flagella.

Herminths sample?

These were passed in a stool specimen from a patient who had No obvious intestinal symptoms. This was observed in the stool (fecal) specimen of a patient. The patient had complained of mild intestinal discomfort and was slightly anemic.

Fungi sample?

These were recovered from a vaginal swab from a woman complaining of a vaginal discharge accompanied b intense vigilance itching.

Why are flowcharts useful for dichotomous keys?

They allow the researcher to visualize relationships between different bacteria.

What is the hallmark of dichotomous keys?

They consist of a series of paired statements, in which only one statement of each pair applies to a given organism.

Which of the following is not a characteristic of members of the Domain Archaea?

They contain a nuclei

How are prions different from other infectious agents?

They lack nucleic acid.

How are viruses different from eukaryotic cells?

They require a host in order to reproduce.

Algae sample?

This was recovered from a sample of pond water.

How many answers are there to a question in a dichotomous key flowchart?

Two

Which of the following conditions in humans is linked to bovine spongiform encephalopathy?

Variant Creutzfeldt-Jakob disease

Which of the following statements best describes why antibiotics are ineffective treatments for the common cold?

Viruses do not possess targets for antibiotics.

Which of the following statements about Protozoa is true?

When conditions become harsh, some protozoa can form a protective capsule, which is called a cyst.

What disease does the human herpesvirus-1 cause?

cold sores or fever blisters

How do pseudohyphae in yeast differ from vegetative hyphae in filamentous fungi? (When the Bacteria Are Away, the Fungi Will Play CH 12)

Yeasts use pseudohyphae to invade host tissue, whereas filamentous fungi use their vegetative hyphae for obtaining nutrients.