Concept explainers
Human herpesvirus-8 (HHV-8) is common in parts of Africa, the Middle East, and the Mediterranean, but is rare elsewhere except in AIDS patients. Genetic analyses indicate that the African strain is not changing, whereas the Western strain is accumulating changes. Using the portions of the HHV-8 genomes (shown below) that encode one of the viral proteins, how similar are these two viruses? What mechanism can account for the changes? What disease does HHV-8 cause?
Western | 3′-ATGGAGTICTICTGGACAAGA |
African | 3′-ATAAACmCTIGACAACG |
Want to see the full answer?
Check out a sample textbook solutionChapter 8 Solutions
Microbiology: An Introduction Plus Mastering Microbiology with Pearson eText -- Access Card Package (13th Edition) (What's New in Microbiology)
Additional Science Textbook Solutions
Biological Science (6th Edition)
College Physics: A Strategic Approach (3rd Edition)
Laboratory Manual For Human Anatomy & Physiology
General, Organic, and Biological Chemistry - 4th edition
SEELEY'S ANATOMY+PHYSIOLOGY
Biology: Life on Earth with Physiology (11th Edition)
- As a general rule, viruses are not considered to be alive based on several reasons. One such reason is that some viruses use RNA as their genetic material instead of DNA. Which of the five biological themes does this violate? Briefly explain why.arrow_forwardThis virus does not conform to the central dogma of molecular biology. Explain the central dogma and how the virus behaves differently. How should the patient to treated? Can the treatments cure the disease?arrow_forwardViruses are made up of the same biomolecules as cellular organisms (DNA, RNA, proteins, lipids, etc.), which are synthesized through enzymatic dehydration reactions from building blocks and disassembled by enzymatic hydrolysis. They infect cells and replicate themselves using resources from the host cells. Scientists discovered a previously unknown strain of virus in the tropical Pacific Ocean and it can infect higher-order eukaryotes. Initial analysis revealed that the virus is mainly composed of nucleic acids, proteins, and lipids. Chemical analysis after complete hydrolysis revealed the following building blocks (by weight): Chemical components Nucleosides Amino acids Lipids, phosphates, and carbohydrates Percentage by weight 20 30 50 Analysis of percentages of nucleosides yielded the following results (by molar ratio): Nucleosides A G T C U Percentage by mole 19 29 19 29 4 Which of the following events mostly involves hydrolysis reaction after the virus infects…arrow_forward
- Syn5 is a virus that infects photosynthetic bacteria belonging to the genus Synechococcus. The Syn5 virion is icosahedral (660 Å in diameter) with a short tail and an appendage called a horn. The horn is located on a vertex directly opposite the tail. Syn5 follows the typical five steps observed for most viruses when they multiply, and progeny viruses are released when the host lyses. The assembly of Syn5 virions involves several proteins, including capsid proteins, scaffolding proteins, a portal protein, a terminase, tail proteins, and horn proteins. To better understand the assembly of Syn5 virions, scientists used a type of microscopy called Zernike phase contrast electron cryotomography. This type of microscopy improves the contrast typically seen for conventional cryotomography. In their studies, the scientists observed several different developing virus particles in infected cells. The particles were: (1) 660 Å icosahedron containing DNA and having a tail; (2) 660 Å icosahedron…arrow_forwardThe genome of a retrovirus can integrate into the host cell genome. What gene is unique to retroviruses, and why is the protein encoded by this gene absolutely necessary for maintaining the retroviral life cycle?arrow_forwardMost humans are not easily infected by avian influenza. How, then, do DNA sequences from avian influenza become incorporated into human influenza?arrow_forward
- Researchers have recently discovered giant viruses that are 1 μm in length, the same size as some bacterial cells. The genomes of these viruses contain over 2 million base pairs of DNA, which is more DNA than is found in many bacterial genomes, and their genomes contain hundreds—in some cases, thousands—of genes. Given these observations and what you know about viruses, should viruses be considered living or nonliving? Give arguments for and against considering viruses as living organisms.arrow_forwardFor the mutations described below, categorize them in each of the following ways: [transition, transversion, insertion, or deletion]; [synonymous, missense, nonsense, frameshift, or regulatory]; [beneficial, deleterious, or neutral] a. A mutation in the SARS-CoV2 virus changes a codon in the gene encoding the spike protein from AAG to AAC. This mutation increases the ability of the virus to spread from person to person. b. Becker muscular dystrophy results in progressive wasting of skeletal and heart muscle tissue. A patient is found to have a mutation in the dystrophin gene (DMD) in the first nucleotide of intron 25. Normally, a G is in this position, but the patient has an A. c. Fur color in house cats is affected by several genes that encode pigment-producing enzymes. One such gene is found to have an additional C after position 45 in orange cats but not in black cats.arrow_forwardThe diagrams below represent nucleic acid genomic material and a finished product after the viral polymerase acted on the genomic material. Name the virus (either family, genus, or particular virus is acceptable) that these diagrams represent. A is B is C is Dis Genomic material Product + sense RNA A 5' VPB -sense RNA 3' VPg 5' -sense RNA 5' cap Derived from infected cell B 3' 5' AAAAA(A) 3 + sense RNA C + sense RNA -sense RNA +sense RNA 5' 3'arrow_forward
- A particular animal virus requires the use of DNA polymerase from its host, since it does not possess its own DNA polymerase enzyme. Which of the following assumptions in A-D would likely be correct regarding this virus? A) O This virus could not be a retrovirus type. B) OIt could be a (-) ss RNA virus. C) O It could be a (+) ss RNA virus. D) O The vVirus life cycle very likely includes going to the host cell nucleus. E) O All ofA-D are correct assumptions.arrow_forwardThe table below shows the properties of the genomes of three different viruses. The data were obtained as follows: Nuclease sensitivity was measured by the ability of deoxyribonuclease (DNase) or ribonuclease (RNase) to destroy the genome (a “+" means sensitivity). The ability of the genome to act as mRNA was tested by incubating it in a cell-free system. If amino acids were incorporated into protein, the data are shown as a Finally, the virus particles were tested for the presence of a virion polymerase. If an enzyme was present, the data show whether it could polymerize deoxynucleotide triphosphates (DNTPS) or nucleoside triphosphates (NTPS). "+. Genome Properties Nuclease Virion Can Genome Sensitivity? Polymerase? Be an mRNA? Virus DNase RNase With With DNTPS NTPS #1 - - #2 - - #3 For each virus, indicate the strategy of the genome, using the Baltimore classification. What is the nature of the product of the virion polymerase when present? + + + + + +arrow_forward5) Name which protein of the coronavirus attaches to host cells: Number of amino acids in this protein: Secondary structures found in this protein: Is this protein highly conserved or variable among different coronaviruses? What information would you need to determine this? Key amino acids in the binding domain of this protein: Is this protein identical among the different viral strains? Which mutations are found in this protein in the omicron variants as compared to the original viral strain? 6) The host (human) protein that serves as the virus receptor is: The normal function of this human protein is: Would this be a good protein to remove so the virus does not have a target to bind? 7) How could knowledge about the structure of the protein:protein interactions between the virus protein and human receptor protein be used to develop therapeutic treatments?arrow_forward
- Human Anatomy & Physiology (11th Edition)BiologyISBN:9780134580999Author:Elaine N. Marieb, Katja N. HoehnPublisher:PEARSONBiology 2eBiologyISBN:9781947172517Author:Matthew Douglas, Jung Choi, Mary Ann ClarkPublisher:OpenStaxAnatomy & PhysiologyBiologyISBN:9781259398629Author:McKinley, Michael P., O'loughlin, Valerie Dean, Bidle, Theresa StouterPublisher:Mcgraw Hill Education,
- Molecular Biology of the Cell (Sixth Edition)BiologyISBN:9780815344322Author:Bruce Alberts, Alexander D. Johnson, Julian Lewis, David Morgan, Martin Raff, Keith Roberts, Peter WalterPublisher:W. W. Norton & CompanyLaboratory Manual For Human Anatomy & PhysiologyBiologyISBN:9781260159363Author:Martin, Terry R., Prentice-craver, CynthiaPublisher:McGraw-Hill Publishing Co.Inquiry Into Life (16th Edition)BiologyISBN:9781260231700Author:Sylvia S. Mader, Michael WindelspechtPublisher:McGraw Hill Education