SB5f Virus life cycles

Question 1

Why are viruses described as particles rather than cells?

Answer 1

.Viruses are acellular, they’re not cells.​
.They all consist of genetic material surrounded by a protein coat (capsid)​
.Viruses cannot copy themselves on their own​

Question 2

What must viruses do in order to reproduce?

Answer 2

viruses must use host cells and this destroys the host which leads to cell damage and death.​

Question 3

What do viruses use to make new virus copies?

Answer 3

host cell machinery e.g. ribosomes. They can then break out of the cells causing lysis.

Question 4

What is the role of the capsid?

Answer 4

to protect the genome.

Question 5

What is the role of the attachment protein?

Answer 5

to allow viruses to invade host cells.

Question 6

What is lysis?

Answer 6

the disintegration of a cell by rupture of the cell wall or membrane.

Question 7

What do viruses that cause cell lysis undergo?

Answer 7

Lytic or lysogenic pathway

Question 8

lytic pathway? APRAR

Answer 8

Attachment ~ virus attaches to surface of host cell
Penetration ~ virus injects its genetic material into host cell
Replication ~ viral genetic material takes control of hosts cells machinery and starts making copies of itself
Assembly ~ newly formed viral components come together to form complete viruses
Release ~ host cell bursts open releasing newly formed viruses

Question 9

lysogenic pathway? APIDA

Answer 9

Attachment ~ virus attaches to the surface of host cell
Penetration ~ virus injects its genetic material into host cell
Integration ~ viral genetic material becomes part of host cells DNA
Dormancy ~ viral DNA remains dormant and is replicated with the host cells DNA during cell division
Activation ~ under certain conditions the viral DNA can become active and enter the lytic cycle