Cancer A2 Flashcards
define tumour
mass of unspecialised cells
formed by uncontrolled cell division
why is cancer more common in old people
cancer takes time to develop and immune system is less effective in older people
how do tumours cause harm
they damage organ concerned causing blockages or exerting pressure on ther organs
define benign tumour
cannot spread to other part of the body and cannot invade neighbouring tissues
how does methylation lead to cancer
methyl groups added to both copies of tumour suppressor genes
transcription of tumour suppressor gene is inhibited
protein not produced that prevents cell division
leading to uncontrolled cell division
what do you call a cause of cancer
a mutagenic agent
how does sunbathing cause cancer
the sun’s radiation contains ultra violet radiation
this causes mutation of genes which control division
why is fair skin more likely to get cancer from sunbathing
less melanin which protects against the UV radiation
why is it important to destroy all cells in a tumour
cell can break off metastasise
remaining cells can divide and from a new tumour
how do mutations lead to cancer
mutation changes base sequence
of gene controlling cell growth/oncogene
or tumour suppressor gene
change protein structure
tumour suppressor genes produce proteins that inhibit cell division therefore cannot do this
leads to uncontrolled cell division (mitosis)
