VIRUSES

Question 1

What is a virus

Answer 1

an infectious, obligate intracellular parasite comprising genetic material( DNA or RNA) surrounded by a protein coat

Question 2

different shapes of viruses

Answer 2

helical
icosahedral
complex

Question 3

Two structures of viruses

Answer 3

enveloped
non enveloped

Question 4

how do viruses replicate

Answer 4

1- attachment to specific receptor
2- cell entry
3- host cell interaction and replication
4- assembly of viron
5- release of new virus particles

Question 5

how do viruses cause disease

Answer 5

• direct destruction of host cells ie polio
• modification of host cell, ie atrophies villi and flattens epithelial cells
• over -reactivity of immune system
  -damage through cell proliferation
  -evasion of host defence

Question 6

name for primary chicken pox

Answer 6

varicella

Question 7

structure of varicella

Answer 7

lipid envelope
dna genome
glycoprotein receptors on surface

Question 8

infectious period of chicken pox

Answer 8

1-3 weeks of incubation
10 days from blister onset

Question 9

progression and name of chicken pox blisters

Answer 9

macule -> papule -> vesicle -> pustule -> crust

Question 10

how to confirm chicken pox

Answer 10

pop lesion with sterile needle
absorb vesicle onto the swap
replace swab in cassette and send for VZV, PCR

Question 11

common treatment for chicken pox

Answer 11

acyclovir

Question 12

examples of viruses that cause direct destruction of cells

Answer 12

influenza
poliovirus
HIV