Viruses

Question 1

Size of viruses?

Answer 1

Small.

Contains genetic material of either DNA or RNA, and a protein coat.

Question 2

Where do viruses live?

Answer 2

They r non living: because they don’t feed, excrete, grow.

Need to live in a host cell.

Can’t survive long outside the host.

Question 3

What r the effects of viruses?

Answer 3

Cause infection as they destroy host cells.

Question 4

What are the treatments for viruses?

Answer 4

Most resolves itself (body fights it off).

Or medicine designed for the specific virus.

Question 5

How do viruses reproduce?

Answer 5

Inject their DNA into their host cell and take over the cells.

Multiply within it until the host cell explodes open.

Question 6

How do viruses affect host?

Answer 6

Viruses must enter a host to reproduce.

Se component of the host cell as a source of energy and use materials to make new viruses.

Ultimately, destroys the host cells.

Viruses exist in two phases

• transmission phase (virion)
• replication phase

Question 7

Acute infections

Answer 7

Reproduction occurs quickly and cells die suddenly e.g. Influenza.

Question 8

Chronic infections

Answer 8

Reproduce slowly and cause slow cell death. Can last years e.g. Hepatitis.

Question 9

Dormant infections

Answer 9

Virus persists inside a cell without reproducing and the cell does not die. Years later the virus becomes active e.g. Shingles.

Question 10

Viruses

Answer 10

Are the smallest known reproducing things.

Are non living - do not carry out life processes within the virus (except reproduction).

Comprise of DNA or RNA surrounded by one or two coats of protein.

They cannot reproduce outside of a cell - they need to enter a host cell to reproduce.

They are host specific - can only infect specific types of cells.