VIRUSES

Question 1

Lytic

Answer 1

host cell is invaded
virus replicates parts and genetic info
multiple viruses activated and released
host cell is destroyed immediately

Question 1

What is a virus?

Answer 1

Small, non-cellular particles that do not embody most of the characteristics of living things.
Can exist ONLY as intracellular parasites.

Question 2

Lysogenic

Answer 2

host cell is invaded
viral DNA becomes part of the host cell’s chromosomes
Provirus – name given to the viral DNA that becomes a part of host chromosome
provirus replicates its parts and genetic info
virus remains dormant (as a provirus) so it’s not active within the cell but continues to
replicate
Can pass through many generations without harm to the host
Can be activated by a stimulus or nutrient changes
These stimuli trigger the lytic cycle and the infection and death of many cells
The exact trigger that causes the switch from lysogenic to lytic is unknown

Question 3

Antibiotics

Answer 3

Substances inhibiting the growth of microorganisms
Do not destroy viruses

Question 4

Vaccines

Answer 4

Liquid preparations of dead or weakened viral/bacterial cells that stimulate the body’s immune system to fight and produce antibodies
Some viruses can cause cancer by adding specific genes to an infected cell transforming it into a
cancer cell