Animal Virus

What type of parasites are viruses classified as?

Obligatory intracellular parasites

Which of the following are general characteristics of viruses?

Contain DNA or RNA

Contain a protein coat

No ribosomes

Viruses have their own ATP-generating mechanism.

False

What are the three main capsid morphologies?

Helical, Icosahedral, Complex

Viruses can exist extracellularly despite having no metabolism.

True

What is a complete, fully developed infectious viral particle called?

Virion

Viruses lack ribosomes, which are necessary for protein synthesis.

What two components are found in all viruses?

Nucleic acid and capsid

What term describes the spectrum of host cells a virus can infect?

Host range

What determines a virus's host preference?

Specific receptor attachment

Viral family names end in the suffix

-viridae

Viral genus names end in the suffix

-virus

How are subspecies of viruses designated?

By a number

Tissue tropism refers to a virus's ability to infect specific tissues.

True

What defines a viral species?

Shared genetic information and niche

On what criteria are viruses classified into families?

Genome structure

Life cycle

Morphology

Why must viruses be grown in living cells?

They are obligatory intracellular parasites

Which methods are used to grow animal viruses?

Living animals

Embryonated eggs

Cell culture

How is viral growth signaled in an embryonated egg?

Death or changes in embryo

What does the acronym CPE stand for?

Cytopathic effects

Observable cell abnormalities due to viral infection are called

cytopathic effects

Which of the following are examples of CPEs?

Cell death

Loss of adherence

Degenerative changes

Continuous cell lines can be maintained indefinitely.

True

Order the steps of animal virus multiplication:

Attachment

Entry

Uncoating

Biosynthesis

Maturation

Release

Where do DNA viruses typically replicate their DNA?

Nucleus of the host

Where is the capsid of a DNA virus synthesized?

Cytoplasm

RNA viruses that can be directly read by ribosomes contain

+ssRNA

What must -ssRNA viruses produce before synthesizing proteins?

+ssRNA

What enzyme do RNA viruses use to replicate their genome?

RNA-dependent RNA polymerase

Match the entry/exit method to the virus type: Fusion

Enveloped Viruses

Match the entry/exit method to the virus type: Lysis

Naked viruses

What is the term for the period when infectious virions are not yet present?

Eclipse period

The process of releasing the viral genome from the capsid is

uncoating

Enveloped viruses typically release from the host cell via lysis.

False

What determines host preference during the attachment phase?

Receptor-mediated attachment

What is another term for the attachment phase?

Adsorption

Acute

Influenza

Persistent

HIV

Recurrent

Herpes Simplex

Latent

Varicella Zoster

Oncogenic

HPV

How is Influenza transmitted?

Aerosol

Which cells does Influenza infect and kill?

Airway epithelial cells

Which are symptoms of Influenza?

Fever

Cough

Aches and pain

What secondary infection can Influenza lead to?

Bacterial pneumonia

Small antigenic changes over time due to mutations are called

antigenic drift

What causes an antigenic shift in Influenza?

Mixing of genes from two viruses

Influenza pandemics are often traced to antigenic shifts.

True

Which Influenza type is associated with severe disease and animal reservoirs?

Influenza A

What are the two main surface proteins of Influenza?

Hemagglutinin and Neuraminidase

Persistent viral infections are generally fatal.

True

What is an example of a persistent viral infection?

Subacute sclerosing panencephalitis

Where does Herpes simplex virus become dormant?

Neurons

What causes the reactivation of latent viruses like shingles?

Stress or lowered immunity

Chickenpox is caused by the

varicella-zoster virus.

Where does the varicella-zoster virus become latent?

Central nerve ganglia

Shingles is limited to one side of the body

True

What process do cells undergo when infected by oncogenic viruses?

Transformation

Which HPV types are associated with 70% of cervical cancers?

Type 16

Type 18

What high-frequency symptom is caused by HPV in the genital tract?

Warts

What does the term 'prion' stand for?

Proteinaceous infectious particle

How can prions be transmitted?

Ingestion

Transplant

Surgical instruments

What is the general name for prion diseases?

Spongiform encephalopathies

Chronic wasting disease

Deer and elk

Creutzfeldt-Jakob disease

Humans

BSE (Mad cow)

Cattle

Scrapie

Sheep

What is the normal cellular prion protein called?

PrPC

What is the abnormal, scrapie-associated prion protein called?

PrPSc

The abnormal prion protein converts the

one

Prions contain a small amount of DNA.

False