mastering bio ch 19

Assuming no apparent health problems, which of the following individuals is most likely to be recommended to be tested for hepatitis C by the Centers for Disease Control and Prevention and the U.S. Preventive Services Task Force?

A man born in 1955.

Which of the following is true?

A patient with hepatitis C may or may not develop serious health problems.

Which of the following events stimulates the production of viral particles in a host cell?

Activation of the host cell by cytokines, growth factors, or antigens.

Which of the following diseases is caused by an organism most similar to the organism that causes hepatitis C?

Ebola, caused by a virus

True or false? The human immunodeficiency virus (HIV) uses reverse transcriptase to make double-stranded RNA copies of its DNA genome.

False

How does HIV cause disease?

HIV kills cells that defend the body against disease.

You are a physician specializing in the most common form of hepatitis C in the United States. What is your area of expertise?

Hepatitis C, genotype 1

Which enzyme inserts viral DNA into the host's chromosomal DNA?

Integrase

What is the function of reverse transcriptase?

It catalyzes the formation of DNA from an RNA template.

Which replicative cycle describes a virus that can integrate its genome into the host cell's genome?

Lysogenic

Classify each phrase as applying to the lytic cycle, the lysogenic cycle, or both types of reproductive cycles of phages.

Lytic: New phages are assembled from viral DNA and Proteins, the cell is lysed, the host is destroyed. Lysogenic: the cell reproduces normally, the viral DNA integrates into the chromosome of the host cell. Both: Viral genes are replicated.

Which statements about viruses are true?

The capsid enters the host cell if the virus is enveloped. Enveloped viruses bud from the host cell. HIV contains revers transcriptase. A retrovirus contains RNA.

How does HIV bind to a host cell?

The viral envelope proteins interact with CD4 and a co-receptor on the cell membrane.

How do enveloped viruses differ from nonenveloped viruses?

They have a membrane-like outer covering.

Sort the items according to whether they may be found only in free virus particles, only in uninfected host cells, or in both viruses and host cells.

Virus Only: Envelope with glycoproteins, capsomere, capsid Host cell only: ribosome Both: protein, DNA, RNA

What is the source of a viral envelope?

host cell membrane

Your aunt has hepatitis C. Which of the following organs is she most likely to need transplanted?

liver

Double-stranded viral DNA is incorporated into a host cell as a _____.

provirus

The genetic material of HIV consists of _____.

single-stranded RNA

Viral DNA makes mRNA by the process of _____.

transcription

In the lysogenic cycle _____.

viral DNA is replicated along with host DNA