microbiology exam 2 hw

Select the three major areas involved in the science of taxonomy

- Classification - Nomenclature - Identification

Select characteristics exhibited by viral capsids. Check all that apply.

- Composed entirely of protein - May be an icosahedral shape - may be helical in shape - protect the viral nucleic acid - composed of subunits called capsomers - may bind to the surface of the host cell

Order the following choices in terms of size, from smallest to largest

1. Viruses 2. Bacteria 3. Yeast 4. Helminths

How does lysogen affect humans?

Bacteria can become virulent due to phage genes, causing greater damage to infected human host - they become pathogenic due to phage genes, which code for toxins / enzymes affecting humans.

You have been a carrier of HSV-2 for many years, with sporadic outbreaks perhaps once a year. You are pregnant and about to deliver your baby. What does your doctor suggest, now that you currently have an outbreak of herpes lesions?

Delivered by cesarean section

Order these steps of the lytic cycle A. Assembly B. Penetration C. Lysis D. Synthesis E. Adsorption

E, B, D, A, C

Taxonomy does not involve

a common name

Viral spikes ____.

attach specifically to host cell receptors

The orderly arrangement of organisms into a hierarchy of taxa is called _____

classification

Fungi that grows as yeasts at one temperature but as mold at another temperature are called ____.

dimorphic

The intertwined mass of hyphae that contains the body of a mold is a ____.

mycelium

When fungal buds remain attached in a row following cell division, the resulting chains of yeast cells are called ______.

pseudohyphae

Fungi produce which structures for reproduction and multiplication?

spores

Select the three choices that represent the primary purposes of cultivating viruses

- To isolate viruses from clinical specimens - To prepare viruses for vaccines - To research the biology of viruses

Which of the following is not a phenotypic method of identification

- antibody response the ones that are: - morphology - acid-fast reaction - endospore production - gram stain reaction

Which of these statements are true? Check all that apply

- norovirus, a non-enveloped enterovirus, is not affected by hand sanitizer - the envelope of the influenza virus is susceptible to the alcohol in the hand sanitizer - alcohols in hand sanitizer affect the phospholipid bilayer of the viral envelope

Place the steps in the correct order to assess your understanding of the general life cycle exhibited by animal viruses

1. Absorption: The virus attaches to its host cell by specific binding of its spikes to cell receptors 2. Penetration: the virus is engulfed into a vesicle 3. Uncoating: the viral envelope is shed thereby freeing the viral RNA into the cell cytoplasm 4. Synthesis (replication and Protein Production): Under the control of viral genes, the cell synthesizes the basic components of new viruses: RNA molecules, capsomeres, spikes 5. Assembly: Viral spike proteins are inserted into the cell membrane for the viral envelope; nucleocapsid is formed from RNA and capsomeres 6. Release: Envelope virus bud off of the membrane, carrying away an envelope with the spikes. This complete virus or visions is ready to infect another cell

Order the following steps to reflect the order in which they occur in the life cycle of an animal virus

1. absorption (attachment) to host cell surface 2. penetration and uncoating 3. synthesis of viral nucleic acid and proteins 4. assembly of viral particle 5. release from host cell

What is the correct order of the stage of replication? 1 = assembly 2 = attachment 3 = transcription / replication 4 = release 5 = penetration

2, 5, 3, 1, 4

Move the terms into the correct empty boxes to complete this concept map describing characterization of fungi

FUNGI macroscopic --> 1. puffballs 2. mushrooms 3. gill fungi ---> reproduce by forming spores microscopic ---> 1. yeasts --> form soft, uniform colonies --> asexual budding mechanism of cell reproduction 2. , dimorphic -- can form either shape 3. molds from mycelium made of --> hyphae which may be --> septet (divided into segments) OR non-septate (continuous cell)

The antivirals used for herpes simplex infections have the ability to completely destroy the virus and permanently cure the latent infection

False

Viral nucleic acid is made inside the bacterium and is combined with the viral protein coat already present outside

False

a naked virus fuses with the host cell membrane

False

The names of the three proposed Domains are: Bacteria, Protista, Eukarya.

False - Archaea - Bacteria - Eukarya (Protista is a kingdom)

Animal viruses always kill cells they infect

False - can go into lysogenic phase / remain latent

fungi have cell walls made of peptidoglycan

False - fungal CW usually contain chitin / cellulose. - bacteria has CW with peptidoglycan

Select the correct descending taxonomic hierarchy (left to right)

Family, genus, species

Why are CD4 counts related to HIV infection?

HIV can only bind to cells with CD4 receptors - in certain white blood cells is where CD4 are. causes infection and destroys those cells

In your microbiology lab, you class is identifying bacteria. You are using dichotomous keys to aid the identification process using the data from a variety of biochemical tests. What problems do you foresee in this procedure?

If you misread a biochemical test or write down the wrong result, the key will likely take you to an alternative organism that is not your unknown bacteria

Which of the following is a taxon that contains all of the other taxa listed?

Kingdom

Choose the term that describes a bacteriophage infection in which the host bacteria are lysed and killed by the infection

Lytic

Place the steps in the correct order to assess you understanding of lytic infections exhibited by bacteriopahge

Lytic Cycle: 1. Absorption (E. coli host, absorbing bacteriophage) 2. Penetration (insert viral DNA) --> Lysogenic Cycle --> Phage DNA becomes a prophage --> phage DNA is replicated as host cell replicates 3. Duplication of phage components; replication of virus genetic material 4. Assembly of new virions 5. Maturation 6. Lysis of weakened cell 7. Release of viruses

When present, what is the viral envelope composed of?

Many lipids

An envelope is acquired during which step of the viral life cycle?

Release

In the condition called athletes foot, the fungus Trichophyton consumes the keratin protein found in hair, nails, and dead skin. Which of the following descriptors does not apply to Trichophyton?

Saprobe - isn't feeding on dead tissue.

which of the following choices is a correct way to type the binomial name of a microorganism?

Staphylococcus aureus (first one capitalized, second lowercase ; BOTH italicized or underlined works)

Which scientific name is written correctly/

Staphylococcus aureus (italicized or underlined)

How are temperate phages replicated?

The phage is replicated along with the hot cell's genome

What will happen once a virus has entered a host cell and uncoated?

The synthesis of new virions will occur

Almost immediately upon entry, the viral nucleic acid alters the genetic expression of the host cell.

True

Infections caused by fungi are called mycoses

True

Members of the same species share many more characteristics compared to those arranged by members of the same kingdom

True

Phage lysozyme digests the host cell wall, releasing the newly made phage, and lysing the host cell in the release step

True

Both lytic and lysogenic cycles eventually lead to bacterial hot cell damage

True - BOTH parasitic

Choose the statement that correctly explains why viruses are referred to as "filterable"

Viruses are able to pass through a filter because of their small size

Select the statement that most accurately characterizes whole-genome sequencing

Whole-genome sequencing can be performed on microorganism

When using pulsed-field gel electrophoresis, mutation in a microbe's genome will show up as ____.

a different pattern of bands

Label the image to test your understanding of virus size relative to other microorganisms

biggest to smallest ranking: 1. E. coli 2. Streptococcus 3. Rickettsia 4. Mimivirus 5. Rabies 6. Adenovirus 7. Yellow Fever

When assigning a scientific name to an organism, ______.

both genus and species name are italicized or underlined

Rabies virus has a _______ host range as compared to hepatitis B virus.

broad

Vegetative hyphae product spores

false - it's the reproductive hyphae that are responsible fr spores. - vegetative responsible for visible growth / nutrient absorption

In producing beer and wine, humans have exploited the microbial ability to ferment sugar to alcohol. The microbes responsible for this process are ______.

fungi

Early taxonomists relied upon the following to classify an organism EXCEPT _____.

genetic analysis of the organism relied on - morphology - organization characteristics - metabolic characteristics

The long, thread-like branching cells of molds are called

hyphae

a mycelium is an intertwined mass of which type of fungal cells?

hyphae

The activation of a prophage to enter the lytic cell is called

induction - activation of viral replication and rest of lytic cycle (prior is just lysogenic)

Which term accurately describes a fungus growing on live human skin?

parasite - fungi usually heterotrophs but in some causes can act as parasite

An infection in animals similar to a lysogen in bacteria is called a(n) ____ infection

persistent - they are harbored by host cells for several weeks / lifetime

Viruses can be used to identify bacteria because of viral specificity for a host cell. This identification method is called ____.

phage typing

Which is not a characteristic of fungi

photosynthetic

Mad cow disease is caused by a noncellular infectious agent called a ____.

prion

Most fungi obtain nutrients from dead plants and animals. These fungi are called ____.

saprobes

The smallest and most significant taxon is a ______.

species

enveloped viruses use glycoproteins called ____ to specifically bind with their host cells

spikes

Which scientific field is involved in the identification, classification, and naming or organisms?

taxonomy

In viral entry by endocytosis ____.

the host cell's plasma membrane surrounds the whole vision and forms a vesicle

Evaluate the statements below and select the one that correctly apply to those characteristics of infection by herpes simplex virus

- Initial infection with HSV-2 may be completely asymptomatic or may be present with very painful vesicles and flu-like symptoms - HSV causing genital herpes enters a period of latency in the ganglion of the lumbosacral spine nerve trunk where microRNAs are through to regulate transcription of the viral genome - Transmission of HSV to a fetus or neonate is more serious than transmission to adult since it can enter the nervous system where it has high morality rate

Analyze the statements below and select those that correctly apply to the unique characteristics of viruses

- Viruses are species-specific and infect cells from all five kingdoms - While viruses are not considered living because they cannot direct their multiplication, they are more than simply an aggregate of macromolecules they can direct the behavior of living cells - viruses have nucleic acid genome ; however, it may be either DNA or RNA and the nucleic acids may be single or double stranded

select the activities of fungi which are considered beneficial from a human perspective. check all that apply

- form associations with plant roots to enhance uptake of water and nutrients - produce antibiotics - conduct fermentation to produce alcohol - contribute to the carbon cycle by decomposing organic matter

Select the methods that represent prominent biochemical tests used in microbial identification

- observation of an end product of a reaction - analysis of oxygen preferences - analysis of the reaction of enzymes such as catalase, oxidase, and coagulase

Choose the term that describes a virus that has a membranous outer covering over its capsid

Enveloped virus

Match the fungal structure with its description - hyphae - yeast - sporangiospores - mycelium - conidia

Hyphase: long thread-like cells Yeast: oval cells that produce by budding Sporangiospores: reproductive spores produce within sac-like structures mycelium: woven intertwining mass of hyphae conidia: free spores not enclosed within a spore-bearing sac

Herpes simplex-1 _____.

None of the choices are correct IT IS NOT: - exclusive to oral mucosa - exclusive to genitourinary tract - confers immunity to herpes simplex-2 - cleared by praziquantel

Choose the phrase that best describes the role of viral surface protein or spikes

Provide means of attachment to host cell surface

Drag and dro the labels into the correct empty boxes to complete this concept map (HW viruses, viroids, and prions)

Targets receptors on specific host cells: Tropism Life cycle of an enveloped animal virus: 1. Absorption 2. penetration --> endocytosis 3. uncoating 4. synthesis --> nucleic acids (if ds DNA --> integration, which may lead to cancer) 5. assembly 6. release --> exocytosis (e.g. budding) 7. virions (tropism is connected to this one)

Choose the term that describes the overall system of discovering, arranging, and naming organisms.

Taxonomy

Which of the following statement regarding HSV-2 (genital herpes) is incorrect

Virus is shed from active lesions only Correct: - can become latent in sacral ganglion - can also infect oral mucosa - can be reactivated by bacterial infections

Virus x can infect rodents and births, whereas virus Y can infect humans. Which has a broader host range?

Virus x

If you could design a drug to "hide" or block sialic acid on respiratory cells, what stage of the life cycle of influenza would be directly impacted?

absorption - silica acid is cell receptor used by influenza. blocking this blocks attachment.

The scientific name of a microorganism is a combination of the _____ name, which is capitalized, followed buy the _____ name, which begins with a lowercase letter.

genus ; species

Trees of life that illustrate the phylogenetic relationships of all organisms were traditionally based on ______; newer methods for determining phylogeny rely on ______.

morphology ; nucleic acid sequences

The key characteristics of the herpes family of virus is _____.

their ability to stay in host cells without causing symptoms

Yeasts are __ fungi, and molds are __ fungi

unicellular, filamentous

Select all of the answers that reflect the contributions that molecular approaches have made to modern taxonomy

- revealed that ssu RNA is highly conserved so can be used for classification - have led to the development of a new taxonomic system divided into domains

Select all of the facts that support the concept the viruses are nonliving agents.

- viruses are not able to reproduce outside of a hot cell - viruses have DNA or RNA, but not both - viruses are unable to carry out metabolic processes to generate ATP

Order the following choices to reflect the organization of taxa from the most general to the most specific, to test your understanding of levels of classification.

1. Domain 2. Phylum 3. Order 4. Species

Herpes simplex-2 (HSV-2) causes _____.

All of the choices are correct - genital lesions - intensely sensitive vesicles on or near the genitals symptoms that include urethritis, cervicitis, and itching - infection in neonate that contact lesions in the birth canal

An occasional serious complication of herpes simplex-1 is ______.

Encephalitis

In humans, fungi can only infect the skin.

False - In humans, fungi can infect skin, mucous membranes, lungs, groin, and other areas

Viruses can be grown on culture media like bacteria

False - require host

All viruses leave a cell by exocytosis

False - some released when cell lyses

Move the terms into the correct empty boxes to complete this concept map describing noncellular infections agents

Noncellular Infectious Agents 1. Prions abnormally-folded proteins --> that typically cause neurological diseases --> such as Creutzfeldt-Jakob in humans --> BSE in cattle 2. viruses infect all five kingdoms --> comprised of capsid --> surrounding a nucleic acid genome --> and lack ribosomes 3. satellite viruses --> such as AAV --> delta agent coinfects with hepatitis B 4. viroids much smaller than viruses --> comprised of naked RNA --> infects plant cells

Choose the statement or characteristic that best describes the current taxonomic system

Three distinct types called domains as the highest taxonomic category

Both enveloped and naked viruses can enter the cell by endocytosis

True

Choose the statement that best describes most enzymatic reaction results observed in the biochemical testing of microbial specimens

Usually visualized by a color change

A saprobe differs from a parasite in that

a saprobe derives nutrients from dead plants and animals, but a parasite derives nutrients from living plants and animals

Every virus particle contains ___

either DNA or RNA

all fungi form hyphae

false

In the penetration step of phage replication, _____.

only the phage nucleic acid enters the bacterial cell

Viral capsids are composed of ______.

protein

In the attachment step of phage replication, _____.

protein fibers in the phage tail attach to receptors on the bacterial cell wall