Virus

Question 1

Who was one of the first people to discover viruses?

Answer 1

French-Canadian Felix D’Herelle

Question 2

What are viruses?

Answer 2

Obligate intracellular parasites that have top infect a cell and use the host to make new copies of itself
-not living but can evolve

Question 3

What was the first bacteria described?

Answer 3

Tobacco Mosaic virus

-only attacks plants even though we ingest it via smoking

Question 4

What are viruses made of?

Answer 4

RNA (single or double stranded) and or DNA (double or single stranded)

Question 5

How do viruses attach to receptors?

Answer 5

Glycoprotein spikes attach to receptor sites on host cells

Question 6

What is reverse transcriptase ?

Answer 6

Transcription from RNA to DNA

Question 7

What is the capsid?

Answer 7

The outside protein shell of the virus

-comes in many different shapes (simple and complex)

Question 8

What is a bacteriophage?

Answer 8

The insect looking visor with a head, neck and legs

Question 9

How do viruses get into their hots?

Answer 9

Need a natural opening, if not the virus will just remain on top doing nothing

Question 10

What is a host range?

Answer 10

Viruses within the range of organisms they can affect but have viral specificity which refers to what cell types they can infect

Question 11

What are bacteriophages and how to they infect bacteria?

Answer 11

Viruses that infect bacteria with releasing lysozyme to destroy they bacterial cell wall peptidoglycan

Question 12

What is the process called in which a virus makes copies of itself in another host?

Answer 12

Replication

Question 13

What are the 5 stages to virus replication?

Answer 13

Absorption- attaching to host

Penetration-virus enters cell

Synthesis-genes are transcribed direct the cost cell cytoplasm to make components of the evirus

Maturation- components assemble into complete virus copies

Release- new virus release which may or may not kill host cell

Question 14

What is the lytic cycle?

Answer 14

Immediate infection, replication and exiting of cell

Question 15

What is the lysogenic/provirus phase?

Answer 15

When virus is dormant in cells until triggered to replicate

Question 16

What is the envelope?

Answer 16

Animal viruses possess an outer lipid membrane

Question 17

How are viruses released from animal cells?

Answer 17

Released via exocytosis which doesn’t kill the cell. Virus con retain a piece of the wall in their envelope and make it easier to defuse into another cell

Question 18

What are Naked animal viruses?

Answer 18

Do not have an envelope, they have many spikes of glycoprotein to recognize and bind to host cell receptors

Question 19

How do you defend against viral infections?

Answer 19

Immune system, also by activation of the immune system to recognize the virus prior to infection

Question 20

What are the 3 theories as to where viruses came from?

Answer 20

1. Groups of genes that evolved and left the cell
2. No tree of virus
3. Early in evolution, virus was a little piece pf DNA or RNA that broke apart form cell division. They were complementary with the cell so it could get back in

Question 21

What is the central dogma?

Answer 21

DNA produces RNA and protein and DNA