3.8.2.3 Gene Expression and Cancer (C20)

Question 1

Epigenetics has been associated with what type of disease

Answer 1

cancer

Question 2

All tumours are cancerous - true or false?

Answer 2

false

Question 3

What is a tumour?

Answer 3

Mass of cell caused by uncontrolled cell division

Question 4

Cancer is…?

Answer 4

abnormal mass of cells that invades neighbouring tissues or can break away forming secondary tumours

Question 5

Two types of tumours are?

Answer 5

benign and malignant

Question 6

Which tumour is cancerous?

Answer 6

malignant

Question 7

Which tumour does not invade neighbouring cells?

Answer 7

benign

Question 8

How do cancers spread?

Answer 8

blood stream or via lymphatic system

Question 9

Name the two genes that control cell division

Answer 9

Proto-oncogenes and tumour suppressor genes

Question 10

What is the function of a proto-oncogene?

Answer 10

stimulate cell division

Question 11

what is the function of a tumour suppressor gene?

Answer 11

slow down cell division

Question 12

what would happen if there was a mutation in a proto-oncogene?

Answer 12

turn into oncogene - uncontrolled cell division

Question 13

what would happen if there was a mutation in a tumour suppressor gene?

Answer 13

uncontrolled cell division

Question 14

Mutations in genes that control cell division cause…

Answer 14

cancer

Question 15

Which type of tumour grows more slowly?

Answer 15

benign

Question 16

How might tumour cells look compared to normal cells?

Answer 16

different shape
larger/darker nucleus
divide more rapidly

Question 17

what does methylation do to the DNA?

Answer 17

adds a methyl group to it

Question 18

In a proto-oncogene what happens to the methylation of the DNA to turn it into a oncogene?

Answer 18

hypomethylation (reduced methylation)

Question 19

In a tumour suppressor gene what happens to the methylation of the DNA to cause cells to divide out of control?

Answer 19

Increase methylation - turn gene off

Question 20

Which type of tumour grows rapidly?

Answer 20

malignant

Question 21

which type of tumour involves using radiotherapy as well as surgery?

Answer 21

malignant

Question 22

Which type of tumour remains compact

Answer 22

benign

Question 23

which type of tumour grows finger like projections into surrounding tissue?

Answer 23

malignant

Question 24

which type of tumour has a capsule?

Answer 24

benign

Question 25

what are oncogenes?

Answer 25

mutated pro-oncogenes

Question 26

How to proto-oncogenes stimulate cell growth?

Answer 26

growth factor binds to receptor stimulating cell division

Question 27

An oncogene can become permanently activated for one of two reasons?

Answer 27

1. oncogene codes for a receptor that is permanently activated 2. oncogene codes for excessive growth factor

Question 28

How do tumour suppressor genes work?

Answer 28

they slow down cell division, repair DNA or tell cells to die

Question 29

what does apoptosis mean?

Answer 29

programmed cell death

Question 30

Which gene regulates cell division and prevents formation of tumours?

Answer 30

Tumour Suppressor Gene

Question 31

if a tumour suppressor gene is mutated what is the consequence?

Answer 31

stops inhibiting cell division and cells divide out of control

Question 32

mutation in a proto-oncogene leads to

Answer 32

oncogenes being activated - uncontrolled cell division

Question 33

mutation in a tumour suppressor gene leads to

Answer 33

Tumour suppressor gene being inactivated - uncontrolled cell division

Question 34

abnormal methylation is common in many tumours - what effect can this have on a tumour suppressor gene?

Answer 34

hypermethylation of a tumour suppressor gene - inactivity - uncontrolled cell division (p53 not made)

Question 35

what is hypermethylation?

Answer 35

addition on methyl groups on DNA - switching off gene expression

Question 36

transcription of genes is controlled by protein molecules called?

Answer 36

transcription factors

Question 37

How would methylation of a tumour suppressor gene lead to cancer?

Answer 37

1. Methylation prevents transcription of gene;turns off gene expression 2. Protein (p53) not produced that prevents cell division/ causes cell death/apoptosis; 3. No control of mitosis; uncontrolled cell growth due to mitosis

Question 38

Describe how alterations to tumour suppressor gene can lead to development of tumours

Answer 38

1. increased methylation of tumour suppressor gene 2. mutations in tumour suppressor gene 3. tumour suppressor gene not expressed 4. Leading to rapid uncontrolled cell division

Question 39

Which cancer gene would be inhibited due to increased methylation?

Answer 39

tumour suppressor gene (TSG) - gene not transcribed!

Question 40

give one way benign tumours differ from malignant tumours

Answer 40

Cells of benign tumours cannot spread to other parts of the body/metastasise OR Cells of benign tumours cannot invade neighbouring tissues;