cancer

Question 1

what inhibits cell division ?

Answer 1

Tumour suppressor genes

Question 2

what stimulates cell division ?

Answer 2

Proto-oncogenes

Question 3

what do cancer cells dervive from ?

Answer 3

single mutant cell

Question 4

what is cancer?

Answer 4

uncontrolled mitosis

Question 5

what doe proto-oncogens do ?

Answer 5

These are normally only switched ‘on’ when growth factors are detected by protein receptors on the cell surface membrane

Question 6

what does proto-oncogens turn into and why ?

Answer 6

oncogenes
due to mutations

Question 7

what happens to oncogenes?

Answer 7

these genes are permanently switched on,

even in the absence of growth factors that would normally stimulate appropriate cell division

The receptor on the cell surface membrane could be permanently activated

A growth factor is produced in excessive amounts

Cells divide too rapidly, it is out of control

Question 8

whats the reason of cancers due to oncogenes?

Answer 8

environmental factors rather than inherited

Question 9

what do tumor supresor genese do ?

Answer 9

These slow down cell division
Repair mistakes in DNA
Instructs apoptosis (programmed cell death)
This maintains normal cell division and prevents tumours from developing
If these genes become inactivated a tumour can develop