Biology 1001A Study Guide - Midterm Guide: Reverse Transcriptase, Dna Virus, Sub-Saharan Africa

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coffeerhinoceros93

31 Oct 2018

School

Western University

Department

Biology

Course

Biology 1001A

Professor

Beth Mac Dougall Shackleton Tom Haffie

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Document Summary

Chapter 23: viruses, viroids, and prions: infectious biological particles. Flu vaccines a(cid:396)e (cid:272)o(cid:373)(cid:373)o(cid:374)l(cid:455) p(cid:396)epa(cid:396)ed usi(cid:374)g (cid:862)killed(cid:863) (cid:894)i(cid:374)a(cid:272)ti(cid:448)ated(cid:895) (cid:448)i(cid:396)uses so (cid:455)ou(cid:396) (cid:271)od(cid:455) (cid:449)ill p(cid:396)odu(cid:272)e antibodies against the virus. Vaccines prime the immune system to recognize specific viral antigens, before infection occurs. Antibodies: highly specific protein molecules produced by the immune system that bind to specific proteins of a pathogen. Not considered alive because they cannot live (cid:449)ithout host, (cid:272)a(cid:374)(cid:374)ot (cid:396)ep(cid:396)odu(cid:272)e, do(cid:374)"t ha(cid:448)e (cid:373)eta(cid:271)oli(cid:272) p(cid:396)o(cid:272)esses, do(cid:374)"t ha(cid:448)e a (cid:272)ell st(cid:396)u(cid:272)tu(cid:396)e (depend on host cells for their functions) Viruses are infectious biological particles rather than organisms. Have either dna or rna that encode coat, nucleic acid replication, and envelope and host cell recognition (if they are an enveloped virus) proteins. Viruses are classified into orders, families, genera, and species using size, structure, genome structure, and how their nucleic acid is replicated. There are 21 families that cause human disease.

Related Questions

1. Select all of the true statements regarding phageconversion.

-The incorporation of viral genesinto the host cell's DNA is an example of phage conversion.

-The expression of the incorporatedgenes and the resulting alteration of the bacterial phenotype is anexample of phage conversion.

-Cholera toxin genes have a viralorigin.

-The cholera toxin is produced bythe virus.

-The cholera toxin itself is transferred to Vibriocholerae by a virus.

2. Viruses grown in media with radioactive sulfur haveradioactive capsids. Why?

Nucleotides contain sulfur

Cysteine amino acids containsulfur

Capsid peptidoglycans containsulfur

Phospholipids contain sulfur

3. Integrase inhibitors work by:

Agglutinating the reversetranscriptase inhibitors

Preventing the incorporation of theviral DNA into the genome

Blocking the final viralassembly

Degrading the viral envelope

4. Once a prophage is formed, the viral genes are reproducedevery time the bacterium multiplies. The genes that encode thelytic cycle are held in check by a repressor protein. Stressinduces the formation of proteases that degrade the repressor. Howwould this affect the prophage?

Apoptosis would be induced.

The virus enters the lyticcycle.

The bacterial genome isdenatured.

The bacterium rejects the viral genes.

5. Can a virus be killed?

No, viruses are non-living andcannot die.

No, viruses are capable ofself-assembly and cannot be permanently killed.

Yes, separating the genes from thecapsid kills it.

Yes, destroying its genome kills it.

6. Which class of drugs would be effective against HIV but notagainst most other pathogenic viruses?

Translation inhibitors that stopassembly of viral proteins.

Nucleotide analogs that haltreplication.

Non-nucleoside reversetranscriptase inhibitors that block reverse transcription.

Receptor antagonists that block viral entry.

7. An unscrupulous malcontent writes a computer program andembeds it in an e-mail that promises lucrative investmentopportunities. The e-mail is sent to thousands of anonymous users,when they open it the program copies itself into the computer'shard drive. The hard drive begins to fill up with copies of theprogram, once it is completely full the computer crashes. Match thecomponents of this story with the components of a viral lifecycle.

1. e-mail containing virus	Virus
2. Innocent user	Binding site onhostcell
3. User's hard drive andCPU	Host cell'sribosomes
4. Program	Uninfected host cell

8. Vaccines work by priming the immune system and inducing theformation of antibodies and memory cells. When the actual virusinfects the host the host's immune system recognizes it andresponds to it. Which feature of viruses helps them thwart thissystem?

	The envelops prevents immune systemrecognition.
	Autocatalytic proteins replicatewithout genetic material.
	The high mutation rate of the viralgenome.
	Integration of viral genescamouflages the virus.
	Shedding the capsid inactivates theantibodies.

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Biology 1001A Study Guide - Midterm Guide: Reverse Transcriptase, Dna Virus, Sub-Saharan Africa

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