Topic 1:7b - cancer

Question 1

Cancer is a result of:

Answer 1

unregulated cell division

Question 2

What gene codes for proteins that promote cell growth and cell division?

Answer 2

proto-oncogenes code for proteins that are activators of the cell cycle. They promote cell growth and division

Question 3

What gene codes for proteins that inhibit cell growth and cell division?

Answer 3

tumour suppressing genes code for proteins that are suppressors of the cell cycle. They inhibit cell growth and division

Question 4

what causes unregulated cell division?

Answer 4

unregulated cell division results in cancer.

This is caused by mutations in proto-oncogenes and tumour suppressor genes

Question 5

what is a tumour?

Answer 5

a mass of identical cells

Question 6

2 types of tumours:

Answer 6

1. Benign tumours do not spread and do not harm the host organism.
2. Malignant tumours harm the host, spread in the body and cause serious illness

Question 7

describe the progression of tumours from benign to malignant

Answer 7

At first, unregulated cell division produces a mass of identical cells, localised into one tissue type, and called a primary tumour.

Later, metastasis occurs: tumour cells break away from the primary tumour, spread to other parts of the body and cause secondary tumours in other tissues.

Question 8

what is a carcinogen?

Answer 8

a carcinogen is an agent that causes mutations in proto-oncogenes and tumour suppressor genes

e.g: ionising radiation, mutagenic chemical agents and viruses

Question 9

define oncogene

Answer 9

Tumour causing genes produced because of mutations in proto-oncogenes

Question 10

why are there checkpoints in the cell cycle?

Answer 10

to check for mutations or damage, so that it can be fixed or the cycle can be discontinued before cancer occurs