cancer

Question 1

what can cause cancer

Answer 1

a mutation in a gene that controls cell division

Question 2

what is an acquired mutation

Answer 2

mutations that occur in individual cells after fertilisation

Question 3

what is the result if a cell divides uncontrollably

Answer 3

a tumour

Question 4

what is a tumour

Answer 4

a mass of abnormal cells

Question 5

what do tumours do

Answer 5

invade and destroy surrounding tissues

Question 6

what is a tumour called if it invades and destroys surrounding tissues

Answer 6

cancer

Question 7

what are the two types of genes that control cell division

Answer 7

tumour suppressor genes and proto-oncogenes

Question 8

what happens if there is a mutation in a proto-oncogene or a tumour suppressor gene

Answer 8

cancer

Question 9

what happens in a normal functioning tumour suppressor gene

Answer 9

they slow cell division by producing proteins that stop cells dividing or cause them to self destruct

Question 10

what is apoptosis

Answer 10

when a cell self destructs

Question 11

what causes apoptosis

Answer 11

tumour suppressor genes

Question 12

what happens if a mutation occurs in a tumour suppressor gene

Answer 12

the gene will be inactivated the protein it codes for won’t be produced and the cells will divide uncontrollably resulting in a tumour

Question 13

what will a mutation occurring in a tumour suppressor gene result in

Answer 13

a tumour

Question 14

what happens in a normal functioning proto-oncogene

Answer 14

they stimulate cell division by producing proteins that make cells divide

Question 15

what happens if a mutation occurs in a proto-oncogene

Answer 15

the gene become over-active, this stimulates the cells to divide uncontrollably, meaning the rate if dividing increases and this results in a tumour

Question 16

what will a mutation in a proto-oncogene result in

Answer 16

a tumour

Question 17

what can develop over years without no obvious symptoms

Answer 17

tumours

Question 18

are all tumours cancerous

Answer 18

no

Question 19

what are the two different types of tumours

Answer 19

malignant and benign

Question 20

tell me about malignant tumours

Answer 20

they are cancers
they grow rapidly and invade and destroy surrounding tissues
cells can break off the tumours and spread to other parts of the body in the blood stream or lymphatic system

Question 21

tell me about benign tumours

Answer 21

not cancerous
grow slower
often covered in fibrous tissue that stop cells invading other tissues
often harmless
can become malignant
can put pressure on organs as they can cause blockages

Question 22

why can some benign tumours put pressure on organs

Answer 22

because they can cause blockages

Question 23

how can tumour cells differ from normal cells

Answer 23

the nucleus is larger and darker and sometimes they have more than one nucleus
they have an irregular shape
they don’t produce all the proteins needed to function correctly
they have antigens on their surface
they don’t respond to growth regulating processes
they divide by mitosis more frequently

Question 24

what can cause tumour growth

Answer 24

abnormal methylation of DNA
increased exposure to oestrogen

Question 25

that does methylation mean

Answer 25

adding a methyl group onto something

Question 26

what is methylating DNA an important process of

Answer 26

regulating gene expression - it can control whether or not a gene is transcribed and translated

Question 27

what does it mean when something is transcribed

Answer 27

copied into mRNA

Question 28

what does it mean when something is translated

Answer 28

turned into a protein

Question 29

when does methylation become a problem

Answer 29

when there is too much or too little

Question 30

what is hypermethylation

Answer 30

too much methylation

Question 31

what is hypomethylation

Answer 31

too little methylation

Question 32

what happens when tumour suppressor genes are hypermethylated

Answer 32

the genes are not transcribed so the proteins they produce to slow down cell division are not made this means cells are able to divide uncontrollably by mitosis and tumour can develop

Question 33

what happens when proto-genes are hypomethylated

Answer 33

causes them to acts as oncogenes increasing the production of the proteins that encourage cell division this stimulates cells to divide uncontrollably which cause the formation of tumours

Question 34

what are some women more exposed to than others

Answer 34

oestrogen

Question 35

what can increased exposure to oestrogen be the result of

Answer 35

earlier menstruation starting the menopause later than usual taking oestrogen containing drugs

Question 36

give an example of an oestrogen containing drug

Answer 36

HRT

Question 37

what can increased exposure to oestrogen over an extended period if time do

Answer 37

increase women's chance of breast cancer

Question 38

how can oestrogen contribute to the development of some breast cancers

Answer 38

stimulation of certain breast cells to divide and replicate, more cell divisions taking place naturally increases increases the chance of mutations occurring so increases the chance of cell becoming cancerous due to the oestrogens ability to stimulate division it also means that if cells become cancerous, their rapid replication could be further assisted by oestrogen, helping form tumours quickly as welk as oestrogen able to introduce mutations directly into the DNA of certain breast tissues increasing the chance of cells becoming cancerous