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