cancer :(

Question 1

factors increasing chances of cancer (4 factors)

Answer 1

environmental factors
- carcinogens (tar and asbestos)
- ionising radiation (UV radiation,xray)
loss of immunity due to infection
- HIV can weaken immune system, reduce body ability to fight infections
genetic predisposition
- gene mutations inherited
age
- accumulation of mutations over time, increased risk

Question 2

proto-oncogene function

Answer 2

codes for proteins that stimulate NORMAL cell division / proliferation

Question 3

oncogenes

Answer 3

mutated proto-oncogenes that accelerate cell division
increase AMOUNT of product and INTRINSIC ACTIVTY of product

Question 4

how does it increase amount of product, leading to uncontrolled cell division? (4)

Answer 4

1. point mutation of regulatory elements (stronger promoter created)
2. gene amplification, number of copies of proto-oncogene increased due to mistake in replication, causing excessive production of growth factor
3. chromosomal translocation, proto-oncogene ends up under control of enhancer
4. retroviral integration (inactivate silencer, insert viral enhancer)