AP BIO Chapter 17 Mastering Biology
What is the genetic material of retroviruses?
RNA
both virus and host cell
RNA, DNA, and protein
The lytic cycle of bacteriophage infection ends with the
rupture of the bacterium
The genetic material of HIV consists of
single-stranded RNA
lysogenic cycle
the cell reproduces normally, viral genes are replicated, and the viral DNA integrates into the chromosome of the host cell
As a result of the lytic cycle,
the host cell's DNA is destroyed
In the lysogenic cycle
viral DNA is replicated along with host DNA
What is the function of reverse transcriptase?
It catalyzes the formation of DNA from an RNA template
How does a virus differ from a bacterium?
Viruses, unlike bacteria, lack metabolic enzymes
What is the source of a viral envelope?
host cell membrane
lytic cycle
new phages are assembled from viral DNA and proteins, the cell is lysed, viral genes are replicated, and the host is destroyed
How many people world wide are infected with AIDS?
60 million
How do prions, which are misfolded proteins, infect organisms?
Prions enter brain cells and cause normal forms of the protein to refold into the prion form
A plant that has been raised in a sterile environment shows symptoms of a viral infection. How would you explain this?
The viral infection was acquired by vertical transmission.
How does HIV cause disease?
They infect the cells that defend the body against disease
Why are retroviruses considered a special class of viruses?
They transcribe RNA to DNA using reverse transcriptase
The H1N1 2009 outbreak is considered a
pandemic
What do we call a virus that attacks a bacterium?
phage
HIV uses which process to synthesize a DNA strand using its RNA genome as a template?
reverse transcription
host cell only
ribosome
How do enveloped viruses differ from nonenveloped viruses?
they have a membrane-like outer covering
Viral DNA makes mRNA by the process
transcription
How do viroids differ from viruses?
unlike viruses, viroids do not encode proteins
What is the most effective way to stop viral infections?
vaccines
Which enzymes inserts viral DNA into the host's chromosomal DNA?
integrase
How do prions differ from viruses?
Unlike viruses, prions do not include any nucleic acids, prions are infectious proteins, and a prion is a single molecule.
A statement that supports the view that most biologists that viruses are nonliving
an isolated virus is unable to replicate its genes or regenerate ATP
Why is it ineffective to treat viral disease with antibiotics?
antibiotics inhibit enzymes specific to bacteria and have no effect on virally encoded enzymes
Which statements about viruses are true? A. All RNA-containing viruses are retroviruses. B. HIV contains reverse transcriptase. C. All viral genomes contain both DNA and RNA. D. The capsid enters the host cell if the virus is enveloped. HIV contains two identical strands of DNA. E. A retrovirus contains RNA. F. Enveloped viruses bud from the host cell.
b, d, e, f
Double stranded viral DNA is incorporated into a host cell as a
provirus
The nucleic acid of a virus particle is enclosed in a protein coat called
capsid
virus only structures
capsid, envelope with glycoproteins, and capsomere
What happens first when a phage infects a bacterial cell and is going to enter a lysogenic cycle?
linear DNA circularizes
Which replicative cycle describes a virus that can integrate its genome into the host cell's genome?
lysogenic