Lab 2: Viruses
enveloped virus
A virus enclosed within a phospholipid membrane derived from its host cell.
Coronaviruses can cause ____.
All of the answers are correct. (COVID-19; common cold; SARS; MERS)
What feature do viruses have in common with cell based life?
All of the answers are correct. (nucleic acid genome; genetic variation; same genetic code as living cells)
____ are known to carry the Ebola virus.
Bats
When was the novel coronavirus discovered?
December 2019
Why do viruses evolve faster than humans?
Many viruses have a high mutation rate, large population size, and a rapid life cycle.
____ can cause symptoms ranging from benign growths on the skin, respiratory tract, or genitals, to several types of cancer.
Papillomaviruses
How is RNAi a useful research tool?
RNAi lets scientists deactivate genes one at a time and see what happens. Researchers use RNAi to deactivate one gene at a time and see what happens to an organism. This helps them determine what biological processes that gene affects.
How does RNAi fight viruses?
RNAi uses chopped up bits of viral RNA to screen mRNA before it's translated.
How does RNAi fight viruses?
RNAi uses chopped up bits of viral RNA to screen mRNA before it's translated. RNAi uses a protein called DICER to cut up double-stranded viral RNA. It then uses those chopped up pieces as a template to spot viral RNA. Proteins check mRNA against this template and slice up anything that matches.
A test for detecting coronavirus infection is ____
Reverse Transcriptase Polymerase Chain Reaction & Blood Antibody Test
The HIV virus infects _____.
T-lymphocytes
How do AZT-like drugs help slow HIV infection?
They inhibit reverse transcription.
Why do viruses attack cells?
To hijack the cell's factory Viruses don't have the machinery to replicate themselves, so they have to take over the cellular factory (ribosomes and other associated molecules).
True or false? A symptom some people with COVID-19 have reported is loss of taste or smell.
True
Glycoproteins
Viral proteins with sugars attached to them are called glycoproteins. Glycoproteins typically bind to receptors on the membrane of a host cell.
"naked" or "nonenveloped" virus
Viruses that do not bud from the host cell membrane; do not have an envelope
Which practice prevents the spread of germs?
Washing your hands often
host
an organism that a virus infects and replicates in
Which is larger, bacteria or viruses?
bacteria
HIV RNA and proteins are packaged and released from the surface of infected cells during a process referred to as ____.
budding
A virus is made up of a DNA or RNA genome inside a protein shell called a/an ____.
capsid
Viruses consist of genetic material (DNA or RNA) surrounded by a layer of viral proteins, called a
capsid
True or false? Viruses can only infect one kind of host.
false
viral genome
genetic material that encodes one or more proteins.
Identify the virus shape in the image, below.
icosahedral
During the lysogenic cycle, phage DNA is _____ _____ the bacterial chromosome.
integrated into
During this phase of a bacteriophage life cycle, the phage kills the cell.
lytic cycle
A virus infects a host in order to:
make copies of itself
An animal virus has surface molecules that let it bind to ____ on the host membrane.
receptors
The novel coronavirus is spread via ____.
respiratory droplets
An enzyme called _____ reads the sequence of viral RNA and converts it to a complementary DNA sequence.
reverse transcriptase
Viral genomes vary in their ________ of nucleic acid (RNA or DNA) and their ________ of nucleic acid strands (written as ss for single-stranded and ds for double-stranded).
type; number
Of the following, which is a feature all viruses share?
A nucleic acid genome made of DNA or RNA
What are the five steps of the virus lifecycle?
1.) Attachment, 2.) Entry, 3.) Genome replication and gene expression, 4.) Assembly, 5.) Release
What is the average incubation period for the coronavirus that causes COVID-19?
5-6 days
