Unit 1 - Virology

Question 0

What is a host range

Answer 0

Spectrum of what the virus can affect. Only affect certain cells such as hair

Question 1

What are the general characteristics of viruses

Answer 1

Can have multiple shapes,
have a capsule and some have an envelope,
no organelles,
have either DNA or RNA or,
need an electron microscope to view, need a host,
lysogenic or lytic cycle

Question 2

What is a bacteriophage

Answer 2

A virus that only affects bacteria

Question 3

What is the structure of a bacteriophage

Answer 3

Have s capsid, nucleic acid and sometimes an envelope

Question 4

What are the five steps of the lytic cycle for a bacteriophage

Answer 4

Attachment, 
penetration, 
biosynthesis, 
maturation,
 release which lyse the cell

Question 5

Describe the attachment phase of the lytic cycle

Answer 5

Specific and based on host range

Question 6

Describe the penetration phase of the lytic cycle

Answer 6

Lysosome makes holes (enzyme)

Question 7

Describe the biosynthesis phase of the lytic cycle

Answer 7

Replication. Uses host cell mechanisms for replication

Question 8

Describe the release phase of the lytic cycle

Answer 8

Lyse the cell to allow virus to infect neighbour cells

Question 9

What are the 5 stages of the lysogenic cycle

Answer 9

Attachment
Penetration
Dna integration
Host cell replication 
Virus dna removes itself from the host cell dna

Question 10

Describe the DNA integration phase of the lysogenic cycle

Answer 10

The virus puts its DNA into host DNA. The virus now becomes a prophage

Question 11

Describe the host cell replication phase of the lysogenic cycle

Answer 11

It also replicates the viruses DNA

Question 12

Describe the virus DNA removal phase of the lysogenic cycle

Answer 12

The virus DNA removes itself from the host cell DNA and can now join the lytic cycle and then go through biosynthesis

Question 13

What’s the difference between animal and bacterial viruses

Answer 13

In animal viruses the full virus goes into the host cell but with bacterial viruses the DNA/rna goes inside

Question 14

How does virus remove its envelope/capsid after penetration

Answer 14

By fusion/endocytosis

Question 15

Where is Viral replication in bacterial infections

Answer 15

In the cytoplasm

Question 16

In DNA animal viruses the replication occurs where

Answer 16

️Nucleus

Question 17

In rna animal viruses the replication occurs where

Answer 17

In the cytoplasm

Question 18

What does a lysogenic cycle mean for an animal

Answer 18

Chronic infections, latent infection, slow viral infection and cancer

Question 19

What happens to a cell if a virus has an envelope

Answer 19

It won’t lyse the cell

Question 20

What happens to a cell if a virus doesn’t have an envelope

Answer 20

It will lyse the cell and steal part of the plasma membrane

Question 21

What are the 4 things a virus needs to cause disease

Answer 21

A route of infection
Disemmenation (to get where it needs to be - generalized or local)
Cause disease (has an incubation period)
Shed and transmit itself

Question 22

Describe an acute disease

Answer 22

Short term, clinical signs, persistant

Question 23

Describe a latent disease

Answer 23

Virus is inside of host cell but doesn’t have symptoms

Question 24

Describe a chronic disease

Answer 24

Virus is present and can be shed

Question 25

Describe a slow infection

Answer 25

Virus load increase over years and eventually kills you

Question 26

What is vertical transmission

Answer 26

Mother to child

Question 27

What is horizontal transmission

Answer 27

Via fomites/vectors from person to person