intro to virus

Question 1

description of viruses:
1. they are infectious agents of — size
2. contain — type of nucleic acid
3. are totally dependent on a —- cell for replication
4. relies on the — process of their — to reproduce themselves , strict intracellular parasites

Answer 1

• small
• one ( either dna or rna )
• host
• cellular
• host

Question 2

virion component:
—- is a proteinaceous coat made of capsomers
—- dna or rna and never both
nucleic acid + capsid gives —–
the envelop is not always —

Answer 2

• capsid
• nucleic acid
• nucleocapsid
• present

Question 3

—– is a protein shell composed of capsomers surrounding the genome , acts as a protective shield , viruses can have them with different —- and —–

Answer 3

• capsid
• shapes and symmetries

Question 4

capsid morphology:
its — and contains —- faces each an ——–
helical and complex

Answer 4

• isosadheral
• 20
• equilateral triangle

Question 5

the role of capsid includes:
1. introduces —– into the hosts : aka the capsid proteins interact w the host cell —-
2. contains —- : which stimulates the hosts —– system
2. resistant to:

Answer 5

• viral genome
• receptors
• antigens
• immune
• drying hear detergent acids proteases

Question 6

true or false:
technically the viruses are not living entities so the common rules applied to living cellular organisms don’t apply

Answer 6

true

Question 7

classification of viruses include

Answer 7

• phenotypic characteristics eg morphology , enveloped or not
• genotype characertsics as the type of nucleic acid
• mechanism of replication
• the host they infect
• diseases they cause

Question 8

the bilayer that surrounds the capsid composed of phospholipids and glycoproteins is known to be —

Answer 8

the envelop
- the viruses without one are called non enveloped viruses

Question 9

the envelop is derived from the —- membranes —-
envelop contains —— which attach the virus to —- on suspecitible host cells

Answer 9

• host cell membrane
• budding
• viral proteins
  -receptors

Question 10

properties of enveloped viruses:
1- confers the distinctive —– characteristics by which some viruses can be —– ( antigen )
2- surface polypeptides can bind —— sites on host cells
3. viral antigens stimulate host —– responses
4. envelopes are sensitive to:
5. conseuqcnes are; they must stay — during transmission cant survive in —– and don’t need to —- cells in order to spread

Answer 10

• serological
• diagnosed
• specific receptors
• immune
• drying heat detergents acid
• wet
• GI
• kill

Question 11

viral acquisition includes:

Answer 11

1. vectors as animals or insects
   - rabies , dengue
2. inhalation
   - influenza , covid , rhinovirus
3. faecal oral
   - rotavirus , norovirus , heptatsis A&E
4. blood borne
   - Hepatitis B&C , HIV
5. sexual
   -HIV , hepatitis B & C
6. congenital
   - rubella , CMB , hepatitis B & C , HIV
   ( check slide 22 )

Question 12

1.viruses only reproduces within —– , they don’t possess the necessary machinery themselves to replicate
2. they must — cell and — the cells reproductive system to make copies of itself

Answer 12

• appropriate
• invade
• utilise

Question 13

the steps for viral replication includes:

Answer 13

1. attachment/fusion
2. penetration/entery
3. uncoating
4. synthesis/replication
5. assembly
6. release

Question 14

1.when capsid protein/glycoprotein to host cell receptor this step is known as —–
2.refers to the virus internalizing into the cell through endocytosis and the envelop fusion with the plasma membrane this step is known as —-
3.refers to the need to make the genome available and the viral nucleic acid into the cytoplasm/ nucleas aka the viral content is released —
4. many strategies for synthesis of viral nucleic acid and protein , the nucleic acid made in nucleas or cytoplasm and the protein sythesis always in cytoplasm —–
5. viral components must —– into complete viruses to go from one host cell to another , the non envelop lysis or exocytosis and the enveloped in by budding

Answer 14

• attachement
• penetration
• unocoating
• synthesis
• assemble

Question 15

viral pathogenesis:
1. interaction w —- tissue : can organism establish a local infection/ systemic infection as: viraemia
2. —— activity: what effect does it have on host tissue
3. —– response: can virus escape immune responses
4. —– : what type of immune repose does the virus initiate

Answer 15

• target
• cytopathological
• immune
• immunophathogy

Question 16

effect of viruses on cell includes:
1. —- : which is a cytopathogenic effect CPE seen on cells
2. —— : where cells can become malignant of pre malignant eg. papillomavirus
3. —— may be subsequently reactive eg, herpes viruses

Answer 16

• death
• transformation
• latent infection

Question 17

viral spread can be:
1. ——- as intracellular bridges HSV
2. —— where virus is released from infected cells ands areas to other cells locally and distally ( haematogenous/ lymphatic cells ) eg. influenza
3. —— from peripheral nerves to CNS eg. rabies HSV
4. —— when viral genome incorporates into the host genome and passed onto the succeeding cell generation as HIV

Answer 17

• intracellular cell to cell
• extracellular
• neural
• nuclear

Question 18

outcomes of viral infections :
1. many viral infections are —- and self — such as covid virus causing common cold
2. may be —- in vulnerable patients such as cytomegalovirus in transplant patient
3. may be — as hepatitis C
4. may — intermittently as herpes simplex virus cold sores
5. may be —– as rabies

Answer 18

-mild
- self limiting
- severe
- silent
- reoccur
- fetal
( infections may be chronic or acute )

Question 19

laboratory diagnosis can be:
1. —- to detect and identify , is it there , what is it , is it viable
2. —– how much of it is there

Answer 19

• qualitative
• quantitive

Question 20

detect/ idetitifying the virus through 3 ways:
1. —– when detecting virus specific dna/rna
2. —- when detecting viral antigen or detect antibody to virus
3. —— to visualise virus EM or effect of LM

Answer 20

• molecular
• serological
• microscopy

Question 21

• fast ( but serological test is faster )
• usually very sensitive
• quantification
• used for: rapid diagnosis of viral infection , guide treatment as HIV viral load and detection of resistance to antiviral drug
  all under —- test

Answer 21

moliuclar ( PCR , RT-PCR )

Question 22

—– type of microscope used for rapid detection of viral antigen in specimens using commercially produced antibodies
—— type of microscope by which it virus-indued masses within cytoplasm of cells , can be pathogenomic without need for culture ( Negri bodies in hippocampal cells in rabies )
—– type of microscope that’s specilized and give quick answers to clinical questions

Answer 22

• immunoFluorescence
• light microscope - inclusion bodies
• electron microscop

Question 23

viruses only replicate within —- cell so they must needed for —-
these cells will be grown in —–
we examine the cells for the effect of viral growth by :
confirm the ID of the virus by ———–

Answer 23

• living
• culture
• artificial culture
• by: cytopathological effect and haemadsorption ( cells acquire the ability to stick mammalian red blood cells )
• by immofluresence , neutralisation , haemadsorption inhibition

Question 24

• disadvantages of viral culture includes:

Answer 24

▪ Slow - up to 4 weeks required for result
▪ Often very poor sensitivity, sensitivity
depends to a large extent on the
condition of the specimen
▪ Susceptible to bacterial contamination
▪ Susceptible to toxic substances which
may be present in the specimen.
▪ Many viruses will not grow in cell
culture e.g. Hepatitis B, diarrhoeal
viruses, parvovirus, papillomavirus.

Question 25

the major advantage of cell culture is that it can determine —– , if the cytopthalogical effect CPE is observed , the virus is —-

Answer 25

• viability
• viable

Question 26

—– is the testing for antigen e.g. HBsAg (Hepatitis B surface antigen) and the testing for the presence of specific antibody produced against viral antigen
– Ideally two samples required (paired sera): one at the onset of
illness & a second after 7-14 days
– Rise in antibodies confirms infection

Answer 26

serology