Exam 19: Viruses

Use the figures to answer the question. Which of the three types of viruses shown in the figure would you expect to include a capsid(s)?

Which of the following statements correctly describes vaccines and how they help prevent viral infection?

Which of the following statements supports the argument that viruses are nonliving?

Emerging viruses arise by

Use the following figure and information to answer the question(s)below. Cells were infected with approximately 1,000 copies of either virus A or virus B at the 0 time point. At five-minute intervals, a sample of the virus and cell mixture was removed. The intact cells were removed from the sample, and the number of viruses per milliliter of culture was determined. Using the data in the figure, how long does it take for virus A to go through one lytic cycle?

Which of the following events or characteristics accounts for someone who has had regular herpesvirus-mediated cold sores or genital sore flare-ups?

Which of the following characteristics, structures, or processes is common to both bacteria and viruses?

The host range of a virus is determined by ________.

Use the following information to answer the question. Poliovirus is an RNA virus of the picornavirus group, which uses its RNA as mRNA. At its 5′ end, the RNA genome has a viral protein (VPg)instead of a 5′ cap. This is followed by a non-translated leader sequence, and then a single long protein-coding region (~7,000 nucleotides), followed by a poly-A tail. Observations were made that used radioactive amino acids similar in structure to those that are found in viruses and other organisms. Short-period use of the radioactive amino acids result in labeling of only very long proteins, while longer periods of labeling result in several different short polypeptides. What conclusion is most consistent with the results of the radioactive labeling experiment?

Use the following information to answer the question. The herpes viruses are important enveloped DNA viruses that cause disease in vertebrates and in some invertebrates such as oysters. Some of the human forms are herpes simplex virus (HSV)types I and II, causing facial and genital lesions, and the varicella zoster virus (VSV), causing chicken pox and shingles. Each of these three actively infects nervous tissue. Primary infections are fairly mild, but the virus is not then cleared from the host; rather, viral genomes are maintained in cells in a latent phase. The virus can later reactivate, replicate again, and infect others. If scientists are trying to use what they know about the herpes simplex virus to devise a means of protecting other people from being infected, which of the following treatments would have the best chance of lowering the number of new cases of infection?

Refer to the treatments listed to answer the question. You isolate an infectious substance capable of causing disease in plants, but you do not know whether the infectious agent is a bacterium, virus, or prion. You have four methods at your disposal to analyze the substance and determine the nature of the infectious agent. I Treat the substance with enzymes that destroy all nucleic acids, and then determine whether the substance is still infectious. II Filter the substance to remove all elements smaller than what can be easily seen under a light microscope. III Culture the substance on nutritive medium, away from any plant cells. IV)Treat the sample with proteases that digest all proteins, and then determine whether the substance is still infectious. If you already know that the infectious agent was either a virus or a prion, which method(s)listed above would allow you to distinguish between these two possibilities?

Refer to the treatments listed to answer the question. You isolate an infectious substance capable of causing disease in plants, but you do not know whether the infectious agent is a bacterium, virus, or prion. You have four methods at your disposal to analyze the substance and determine the nature of the infectious agent. I Treat the substance with enzymes that destroy all nucleic acids, and then determine whether the substance is still infectious. II Filter the substance to remove all elements smaller than what can be easily seen under a light microscope. III Culture the substance on nutritive medium, away from any plant cells. IV)Treat the sample with proteases that digest all proteins, and then determine whether the substance is still infectious. If you already know that the infectious agent was either bacterial or viral, which method(s)listed above would allow you to distinguish between these two possibilities?

Which of the following descriptions correctly identifies the main structural differences between viruses with envelopes and viruses without envelopes?

Which of the following statements accurately describes the lysogenic cycle of lambda (λ)phage?

Which of the following statements best reflects what we know about how the flu virus moves between species?

Use the figure to answer the question. In the figure, at the arrow marked II, what enzyme is being utilized?

If a viral host cell has a mutation that interferes with the addition of carbohydrates to proteins in the Golgi apparatus, which of the following processes could likely result?

In 2009, a flu pandemic was believed to have originated when viral transmission occurred from pig to human, thereby earning the designation "swine flu." Although pigs are thought to have been the breeding ground for the 2009 virus, sequences from bird, pig, and human viruses were all found within this newly identified virus. What is the most likely explanation of why this virus contained sequences from bird, pig, and human viruses?

Viruses use the host cell's machinery to make copies of themselves. However, some human viruses require a type of replication that humans do not normally have. For example, humans normally do not have the ability to convert RNA into DNA. How can these types of viruses infect humans, when human cells cannot perform a particular role that the virus requires?

A person is most likely to recover from a cold due to viral infection if the infected cells are able to perform which of the following processes?