Viral Oncogenes

Question 1

How can viruses cause cancer

Answer 1

1 carry copy of oncogene into cell

2 alter gene structure causing mutation of Proto-oncogene or tumor suppressor genes

Question 2

2 types of viral oncogene

Answer 2

1 DNA tumor virus

2 RNA tumor virus ( retrovirus )

Question 3

What gap knew when virus resides in cell

Answer 3

-alters properties of cell transforming it causing 
1 loss of growth 
2 ability that invade ecm 
3 de-differentiation 
4 immortalization

Question 4

How does virus alter cell cycle

Answer 4

• alters gene responsible for generating proteins for controlling cell cycle
• proteins which control cell cycle

Question 5

2 lifecycles of viral oncogene and describe

Answer 5

1 permissive - all parts of viral genome incorporated into host leading to viral replication and cell death

2 non-permissive - viral DNA incorporated at random sites on host DNA. No synthesis of vital proteins

Question 6

Condition for retroviruses to work

Answer 6

-must be copied / changed into DNA before being incorporated into host DNA