MCB 3020L Chapter Notes - Chapter 20: Lysogenic Cycle, Protoplasm, Capsid

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orchidbeaver616

21 Mar 2017

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Viruses (part 2: temperate viruses tend to undergo a lysogenic pathway in order to multiply the number of viral particle present: When the host cell reproduced it also reproduces the viral nucleic acids and the daughter cells contain the copies of the viral genetic material. The viral infection will stay that way until conditions are deemed favorable for their release, when they will switch to a virulent pathway (lytic pathway) At which point they will switch to a lytic pathway, which will then initiate the mass replication and the release via the lysing of different cells. Steps: attachment, penetration, protein synthesis, assembly, release. Bacteriophages: viruses that are specific to bacterial hosts. In order to observe a viral infection in a cultured form, we must provide the virus with a suitable host that it can live within. Viral infections can be viewed on an agar plate: infection will initiate, lytic pathway: patches (plaques) of dead bacteria.

Related Questions

QUESTION 1: The rabies virus primarily affects the nervous system. The specificity that the rabies virus has for neuronal host cells is primarily dictated by __________________________.

A. the helical shape of its viral capsid

B. the type of nucleic acid used for its viral genome (single-stranded, antisense RNA)

C. the spikes that protrude from its viral envelope

D. the segmented nature of its viral genome

QUESTION 2: Which of the following genome types has been observed in viruses? To be marked correct, you'll need to select all true statements, as there may be more than one correct answer.

A. Single-stranded RNA

B. Single-stranded DNA

C. Double-stranded RNA

D. Protein-based

QUESTION 3: Choose the correct statement about viral evolution.

A. RNA and DNA viral genomes evolve at equal rates.

B. Cellular genomes mutate at a faster rate than viral genomes due to their large size and increased chance of replicative mistakes.

C. DNA viruses mutate faster than RNA viruses because thymine is more susceptible to mutation than uracil.

D. RNA viruses mutate faster than DNA viruses due to a lack of proofreading replicative enzymes.

QUESTION 4: Your elderly patient is affected by shingles. After careful observation, you note that the virus responsible for the infection has an icosahedral capsid, is enveloped, and has double-stranded linear DNA as its genetic material. Based on this information, in which of the following viral families would you group this viral pathogen?

QUESTION 5: Which of the following is a key difference between lytic and lysogenic bacteriophage replication cycles?

A. Lysogenic bacteriophages release via host cell lysis, whereas lytic bacteriophages bud off from the host cell membrane.

B. The lytic replication cycle ends with host cell lysis and release of newly formed bacteriophage particles, whereas lysogenic replication leads to prophage formation.

C. Lytic replication requires an uncoating step, whereas in lysogenic replication, the bacteriophage's nucleic acid is directly injected into the host cell.

D. Whereas lytic replication enables the infection of several hosts, lysogenic replication only allows for infection of a single host cell.

QUESTION 6: Which of the following is an unsuitable culture method for an animal virus?

A. Direct inoculation of virus onto blood agar

B. Live animal inoculation