Micro Lab 4 Questions

Which of the following characteristics doesn't describe viruses?

they exhibit metabolism while outside of the host cell

Which domain of life do viruses belong to?

viruses don't belong to a domain

Which of the following characteristics describe viruses?

they are filterable (can pass through a filter)

True or False? Viruses obtain their envelop by encapsulating themselves with the host cell’s plasma membrane as they exit the cell.

True

What type of microscopy must be used to visualize most viruses?

electron microscopy

True or False? In general, when comparing sizes of viruses, prokaryotes, and eukaryotes, prokaryotes are the smallest.

False

Match the virus in the left column to its shape from the dropdown menu.

Ebolavirus-helical

smallpox virus-complex

bacteriophage-complex

adenovirus-icosahedral

Match the viral capsid structure in the left hand column to the letter that identifies it from the drop down menu.

helical-a

complex-c

icosahedral-b

Which type of pathogen posses peplomers?

virus

A polyhedral virus that has 20 triangular-shaped sides are called _______ viruses.

icosahedral

"Naked" viruses lack what structural component?

envelope

Viruses are surrounded by a protein capsid composed of individual subunits called _____.

capsomeres

True or False? For a spike virus to infect a host cell, the cell must posses a specific receptor that is recognized by the viral spike.

True

True or False? Mutation in the sequence that codes for viral spike proteins are never beneficial to the virus.

False

Which of the following is NOT a characteristic used to classify viruses?

Cell wall compostion

Which structure of viral nuclei acid is used directly as mRNA that is translated using the host cell’s machinery and molecules?

ssRNA+

HIV is a retrovirus. What viral enzyme is used to produce a dsDNA copy of its ssRNA+ genome?

reverse transcriptase

A ______ is an infectious viral particle that has yet infected its host's cells.

virion

What is the host cell receptor located on the lung and heart cells that SARS-CoV-2 viral spikes recognize?

ACE-2

Why are RNA viruses that use RNA-dependent RNA polymerase for transcription more likely to have genome mutations?

the enzyme doesn't have proofreading capabilities

Antigenic ____ occurs when advantageous mutations in viral genomes result in minor chnages.

drift

Antigenic _____ occurs when there is a reassortment of genetic material from coinfecting viruses that produce a new viral stain.

shift

Which of the following is not a disease caused by prions?

Lou Gehrig's disease

Prions are ________.

misfolded proteins

Mad cow disease is transmitted to humans by ______.

consuming contaminated beef

The presence of specific ______ on viruses determine whether it can infect a particular cell or not.

receptors

The first human virus was discovered in 1901. What scientist discovered the first human virus?

Walter Reed

Some scientists theorize that an ancient virus infected a bacterium helping it produce the first cell _____.

Nucleus

The prefix “corona-” means “crown”. What structure makes the coronaviruses look “crowned”?

spike

What diagnostic tool is use to detect certain genetic markers of SARS-CoV-2?

reverse transcriptase PCR

The serological test (blood test) for COVID-19 spoken of in the Coronavirus disease (COVID-19) video assesses is a person has ____ to the virus in their blood.

antibodies

A significant increase in what secondary protein structure makes infectious prion protein protease resistance?

beta sheets

Which of the following abbreviations represent the infectios prion protein?

PrP^SC