Microbiology chapter 13

During viral replication, when the genome of a (+) single-stranded RNA virus is used as a template, what is generated?

(-) single-stranded RNA molecules

In ________ strand RNA viral genomes, the genome functions as an mRNA molecule.

+

In enveloped viruses, sandwiched between the nucleocapsid and the envelope is the ___________.

Matrix protein

In animals, replication of most DNA viruses occurs within the host cells ___________.

Nucleus

Phage DNA and proteins are made during the _________ step of the T4 lytic cycle.

Synthesis

Reverse transcriptase synthesizes

Viral DNA from viral RNA

A ___________ is a single virus particle

Virion

When two different strains of a segmented virus enters the same cell, reassortment of the gene segment can occur, resulting in __________.

antegenic shift

The nucleocapsid is composed of___________. Hint it's two things**

DNA or RNA, and protein

Viral genomes can be: 1. Either single-stranded or double stranded 2. Double stranded only 3. Double stranded DNA or single-stranded RNA 4. Single-stranded only

Either single-stranded or double stranded

The phospholipid bilayer found surrounding the capsid of some viruses is the _________.

Envelope

True or false: lysogens are more susceptible to reinfection by the same type of phage.

False

The replication scheme of double stranded DNA viruses ________.

Follows the central dogma of molecular biology

_____________ transduction is the result of packaging errors during the assembly stage of phage replication.

Generalized

Symptoms of acute viral disease is result from _________.

Host tissue damage and host immune response

During the process that leads to lysogenic infection, which of the following and search the phage DNA antibacterial chromosomes? Integrase Gyrase Isomerase Polymerase Lysozyme

Integrase

Lysogeny is best described as

Integration of the viral genome into the host chromosome

A __________ phage can either cause a lytic infection or can incorporate its DNA into the host genome as a prophage

Temperate

Bacterial phages that can enter into a lytic cycle or a lysogenic cycle are called ________ phages.

Temperate

The replication strategy of viruses can be divided into three general categories: those used by

DNA viruses, RNA viruses, reverse transcribing viruses

____________ infections remain for years, or even the lifetime of the host, sometimes without any symptoms.

Persistent or chronic

What are the two types of relationships bacteriophages can have with their host?

Productive lytic infection and latent infection where host cell genotype is change

Reverse transcriptase is a(n) ___________ polymerase.

RNA dependent DNA

Replicases are __________ polymerases.

RNA dependent RNA

Add minimum, all viruses are composed of which of the following: lipids nucleic acids proteins carbohydrates

Nucleic acids and proteins

RNA viruses have a higher mutation rate than DNA viruses because replicases typically lack ____________ ability.

Proofreading

In the lysogenic infection, the phase DNA that is incorporated into the bacterial host genome is called a __________.

Prophage

All of the following are required for synthesis of new virus particles in a host cell except __________. RNA synthesis Genome replication Homologous recombination Protein synthesis

Homologous recombination

What is the outcome of phage replication during productive infection

New viral particles are produced

They are immune to infection by the same virus and may have new properties.

Lysogenized cells

Naked viruses do not have an outer lipid bilayer. These viruses are called ________-_________ viruses.

Non-enveloped

Infection of bacteria by _________ phages always ends with the lysis of the host cell

Lytic, virulent, or T4 Either answer is correct

DNA viruses often include their own DNA _______ for DNA synthesis, which allows them to replicate even if the host cell is not actively duplicating its own chromosome.

Polymerase

The viral envelope closely resembles the __________.

Eukaryotic cytoplasmic membrane

Bacteriophages play a fundamental role in a type of horizontal gene transfer called __________.

Transduction

What term is used to describe the transfer of genetic information from one bacterium to another bacterium by a bacteriophage?

Transduction

True or false: viruses contain either DNA or RNA.

True

What characteristics can be utilized to classify and categorize viruses?

1. Type of nucleic acid 2. Host infected 3. strandedness of nucleic acid (positive/negative sense) 4. Capsid size 5. Disease symptoms 6. presence or absence of an envelope

Replication of single-stranded DNA viruses is quite similar to that of double-stranded DNA viruses, except that ______________.

A complement to the single stranded DNA molecule must be synthesized

What are the two major categories of viral infections?

Acute and persistent

The accumulation of mutations in genes that encode viral surface proteins recognized by the immune system results in a type of antigenic variation called ___________.

Antigenic drift

In which phase of the T4 phage lytic cycle of new phage particles put together?

Assembly

The ____________ or maturation stage of the T4 phage lytic cycle is marked by the formation of new phage particles inside the host cell.

Assembly

The binding of a bacteriophage surface proteins to a host cell receptor is called

Attachment

Replication of temperate phages and lytic phages have which steps in common?

Biosynthesis of viral components Attachment Assembly Release Genome entry

Animal viruses can be grown in: bacterial cell cultures. or Can only be grown in animal cells. Which one?

Can only be grown in animal cells

The viral genome is protected from the environment by a proteins shell called the ___________.

Capsid

Big Daddy's favorite type of cake is ?

Carrot cake

The hepatitis B virus sometimes causes an infection their results in a continuous and low level production of virus particles. This type of infection patterns is specifically described as a(n) ___________ viral infection.

Chronic

When an enveloped virus gains entry to an animal cell by fusion, the virus envelope fuses with the __________.

Cytoplasmic membrane

The study of bacteriophages has advanced much faster than investigations on animal viruses in part because _________.

It is easier to grow bacterial cells than animal cells

Why are bacterial phages easier to study than animal viruses?

It is easier to grow the bacteriophage host cells in the lab.

Enveloped viruses have an outer layer made up of_______.

Lipid

A ___________ infection results from the integration of bacteriophage DNA into the chromosome of the bacterial host.

Lysogenic

Some pathogenic bacteria produce toxins that are encoded on prophage DNA, and these are examples of _________ conversions.

Lysogenic

In a(n) _________ viral tiger can be determined by counting clear zones in a monolayer of cells.

Placque assay

The stage of viral multiplication at which budding occurs is

Release

The virally encoded polymerase needed for replication of RNA viruses is called ________.

Replicase

HIV is described as a ___________ because it uses reverse transcriptase to make a DNA copy from its RNA genome.

Retrovirus

Viruses that have an RNA genome and use reverse transcriptase to synthesize a DNA copy of that genome are called __________.

Retroviruses

Retroviruses such as HIV have a unique enzyme that allows them to synthesize DNA from an RNA template. The name of the enzyme is ______________.

Reverse transcriptase

Re-assortment of gene segments that encode viral surface proteins recognized by the immune system can result in a loss of the immune system's ability to recognize and respond to the virus. This phenomenon is called antigenic __________.

Shift

A capsid is

The protein coat that surrounds the viral genome

Human cells are larger than viruses by which size factor? Millions, billions, thousand or trillion

Thousand

The most common method used today in the cultivation of animal viruses is__________.

Tissue culture

Methods for cultivating animal viruses include ________ and __________.

Tissue cultures and embryonated chicken eggs

Consequences of lysogeny include __________

immunity to superinfection and lysogenic conversion

A generalized infection cycle of an animal virus can be divided into five steps

1. Attachment or adsorption 2. genome entry 3.synthesis 4.assembly 5. Release

Mutations in the influenza virus genome can result in minor changes in key viral surface proteins. This type of variation is called Antigenic _________.

Drift

A bacterium being examined in a microbiology laboratory is found to be lysogenized by phage A. The bacterium will exhibit a new _____________ but may not exhibit a new ______________.

Genotype phenotype

In the case of animal viruses, the molecules that viral spikes attach to on the host cell in order to gain entry are typically __________.

Glycoproteins

What soda does Big Daddy always get from the vending machine?

Grape soda

The best known chronic infection involves

Hepatitis B

Which of the following describes a consequence of misogyny that could result in human disease? Exocytosis Phage cycling Host cell lysis Lysogenic conversion

Lysogenic conversion

What are the steps of an animal virus infection cycle

Attachment Penetration and uncoating Synthesis of viral proteins and replication of the genome Assembly Release

If viruses are present in high enough concentrations in a sample, they can be quantified directly using a(n) ______________ microscope

Electron

The process by which a virus is taken up by a host cell as a result of the host cells cytoplasmic membrane surrounding the Virion to form a vesicle is called __________.

Endocytosis

___________ transduction is the result of excision errors made as temperate phages transition from a lysogenic to a lytic cycle.

Specialized

In the region of budding, the cytoplasmic membrane acquires _____________.

Spike proteins and matrix proteins

Attachment of animal viruses to the host cell typically occurs by means of __________.

Spikes

Many animal viruses have proteins called_________ that attach to receptors on host cells.

Spikes

The viral proteins that stick out from either the lipid bilayer of enveloped viruses or the capsid of non enveloped viruses, and attach to host cells, are __________.

Spikes

Which type of viruses are released by budding?

Enveloped viruses

How does bacteriophage nucleic acid into the host cell?

Injection

____________ is a change in the phenotype of a lysogen as a consequence of the specific prophage it carries.

Lysogenic conversion

A complete viral particle, which typically consist of nucleic acid surrounded by a protein cold, is called a(n)__________.

Virion

What is the outcome of phage replication during latent state

Viral genome remains silent within the cell

Bacterial phages the exit the whole cell at the end of an affection by lysing it are called ___________ phages.

Virulent or lytic

May be lysogenic and enters a lysogenic or lytic lifecycle shortly after entering the host cell.

Temperate phage

True or false: some lysogenic phages can increase the pathogenicity of the bacterial host.

True