Midterm 2 - Chapter 13

Question 1

Virion

Answer 1

Fully developed infectious viral particle. Has nucleic acid and protein coat

Question 2

Nucleic acid

Answer 2

can have DNA or RNA as primary genetic material. Can be single stranded, double stranded, linear or circular.

Question 3

Capsid

Answer 3

• Protects nucleic acid
• made up of proteins
• Viruses are defined by their coats
• has subunits called capsomeres
• arrangement of capsomeres is characteristic

Question 4

Envelope

Answer 4

• Combination of lipids, proteins and carbohydrates

- Offers extra protection

Question 5

Spikes

Answer 5

• Made up of protein and carbohydrates

- Used as identification

Question 6

NA spike

Answer 6

• fewer in number than HA

- Used to separate from host cells

Question 7

HA spike

Answer 7

• Hemaglutination

- Aggregates hosts blood cells

Question 8

Lytic cycle

Answer 8

ends with lysis and death of host cell

Question 9

Lysogenic cycle

Answer 9

Host cell remains alive

Question 10

What is HIVs enzyme?

Answer 10

Reverse transcriptase (humans do not have this)

Question 11

HIV can only replicate in:

Answer 11

Human cells

Question 12

HIV 1

Answer 12

prevalent in US and Europe

Question 13

HIV 2

Answer 13

prevalent in west africa

Question 14

Stage A

Answer 14

• 500/mm3

- clinical latency

Question 15

Stage B

Answer 15

• 200-499/mm3
• Persistant fever and diarrhea
• Oral hairy leukoplekia

Question 16

Stage C

Answer 16

< 200/mm3

- Signs of TB, pneumonia, brain degeneration, rare cancers, loss of eyesight (Herpes 5)

Question 17

Lytic infections

Answer 17

Acute. Kills cells but you get better. Ex: cold

Question 18

Persistant infections

Answer 18

Never goes away. Does not kill cell. Produces new virions. Ex: measles

Question 19

Latent infections

Answer 19

Hides and emerges and then produces new virions.

Question 20

Cancer:

Answer 20

Herpes 4: Burkitts lymphoma, tumour of jaw region. Attacks B-cells. Nasopharyngeal carcinoma.