Biology 1001A Chapter Notes - Chapter 23: Dna Virus, Animal Virus, Bacteriophage

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amethystarmadillo903

13 Jan 2018

School

Western University

Department

Biology

Course

Biology 1001A

Professor

Beth Mac Dougall Shackleton Tom Haffie

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What is a virus: nonliving infectious biological particles rather than organisms, one or more nucleic acid molecule surrounded by a coat or capsid. Some capsids may be enclosed within an envelope derived from host cell membrane: genome can be dna or rna that encode for coat proteins and regulate transcription. List three features of viruses that distinguish them from living organisms: cannot reproduce on their own, lack a metabolic system, do not have cytoplasm enclosed by plasma membrane, so not a cell. Structural forms: helical viruses, protein subunits assemble in a rod-like spiral around genome. Tobacco mosaic virus: polyhedral viruses, coat proteins form triangular units that fit together like parts of a soccer ball, protein spikes extend from corners and provide host cell recognition. Hiv: complex polyhedral viruses, has a sheath and tail fibres which play a role in the infection process, head encloses viral dna, ex. 23. 2 viruses infect bacterial, animal, and plant cells by similar pathways.

Related Questions

1. Unlike Ebola virus, SARS virus
a. has large spikes that look like a âcrownâ.
b. is enveloped.
c. is helical.
d. is in the family Togaviridae.
e. is a ssRNA virus.

2. Which virus or virus family is described in the followingpassage?
Electron micrographs of the hemagglutinin subunits (in the presenceof SDS) showed
rods approximately 40 Ã wide and 140 Ã long. The neuraminidasesubunits had a quite
different appearance. In the presence of SDS, these were seen asoblong structures about 85 Ã long and 50 Ã wide with a centrallyattached fibre 100 Ã long possessing what appeared to be a diffusetail or small knob about 40 Ã in diameter at its end.1
a. Togaviridae
b. Epstein-Barr virus
c. Smallpox virus
d. Orthomyxoviridae
e. Filoviridae
f. Rabies virus

3-Following is a passage from the New England Journal ofMedicine:
______________________ is an exclusively human herpesvirus that ...becomes latent in
cranial-nerve and dorsal-root ganglia, and frequently reactivatesdecades later to produce shingles and postherpetic neuralgia. Inimmunocompetent elderly persons or
immunocompromised patients, ____________________ may producedisease of the central nervous system.
This passage refers to which virus?
a. West Nile virus
b. Smallpox virus
c. Epstein-Barr virus
d. Ebola virus
e. Varicella-zoster virus

4. Pneumoviruses can cause colds and pneumonia in humans. They aresingle-stranded,
negative-sense, nonsegmented RNA viruses. These enveloped virusesare surrounded by an envelope that is characterized by fusionglycoproteins and host-derived proteins. With this knowledge, it islikely that pneumoviruses
a. enter host cells via endocytosis.
b. leave host cells by budding.
c. enter host cells via membrane fusion.
d. A and B
e. B and C

5. Recall that poliovirus is a positive-sense (+) ssRNA virus. The5â Ã ? 3â strand of RNA,
once uncoating has taken place, can serve as an mRNA and encode forviral proteins.
However, in order for the virus to create more +ssRNA to package indaughter viruses, it must
a. generate a dsRNA molecule that can encode for the synthesis ofmore +RNA.
b. integrate into the host cell DNA.
c. utilize an RNA-dependent DNA polymerase to make aheteroduplex.
d. undergo reassortment
e. All of the above

6. Some influenza hosts, such as humans and pigs, cansimultaneously contract human,
avian and swine influenza viruses at the same time. What can occurduring the maturation phase of virus replication in such ahost?
a. Reassortment
b. RNA of all three sources: human, swine and avian, can bepackaged into a single
virion.
c. Genetic shift
d. All of the above

7. The HIV virion contains enzymes/proteins that do all of thefollowing EXCEPT
a. An enzyme that creates âDNA using +RNA as template.
b. A protein that serves as a chemokine receptor.
c. A DNA-dependent DNA polymerase.
d. An enzyme that allows +/- viral DNA to be spliced into the hostcellâs DNA.
e. A protein that mediates membrane fusion.

8. After a long series of biochemical tests, Kyle and Matt werefinally able to identify their Gram-negative unknowns asPseudomonas aeruginosa and Shigella dysenteriae,
respectively. As they compare notes, they realize that theirunknowns are in the
___________ Pseudomonadaceae and Enterobacteriaceae, respectively.However, they also note that both of their unknowns are in the______________ ? proteobacteria.
a. genera, species
b. phyla, family
c. families, class
d. order, phyla
e. classes, order

9-Hydrogenobaculum acidophilum is a resident of YellowstoneâsNorris Geyser basin. This thermoacidophilic microbe grows instringy, white mats and is a member of the phylum Aquificae.Hydrogenobaculum acidophilum
a. could be further researched in Volume 2 of Bergeyâs Manual ofSystematic
Bacteriology.
b. is in the domain Archaea.
c. is a deeply branching bacterium.
d. is a proteobacterium.
e. All of the above

10-After talking about the Group A Streptococci (GAS) and theircapability to sometimes cause a flesh-eating disease callednecrotizing fasciitis, Derek decides to research this group a bitmore. As he reads, he quickly learns that
a. they are microaerophilic Gram-negative rods.
b. they are in the phylum ?-proteobacteria.
c. they are found Volume 4 of Bergeyâs Manual of SystematicBacteriology.
d. they have less than 50 mol % GC content.
e. none of the above

Biology 1001A Chapter Notes - Chapter 23: Dna Virus, Animal Virus, Bacteriophage

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