ALL CELLS ARISE FROM OTHER CELLS - Cancer Flashcards
what causes cancer?
Mutation in the DNA which controls cell division can cause cells to grow out of control
what affects the rate of cell division?
its environment : nutrients, oxygens ,hormones
what is a mutation and how can it be caused?
Mutations are changes to the base sequence of the DNA, these can be caused by mutagens such as ioinising radiation from UV rays, carcinogenic chemicals (eg cigarette smoke).
How can cancer cells die?
via apoptosis or they can be destroyed by the immune system which recognises them as foreign.
how are tumours linked to cell division?
tumours are caused by
uncontrolled cell division.
what is a benign tumour?
tumour which grows slowly and is kept in one place. it does not invade neighbouring tissues and start tumours in other organs.
what is a malignant tumour?
tumour which grows rapidly and invades other tissues. it can break off and spread around the body , causing tumours in other parts of the body.
Why are tumours harmful?
Jameson damaged organs they grow in, they can cause blockages or they can cause damage to other organs.
What is the role of cancer treatment?
It can control the rate of cell division in cancer cells by targeting the cell cycle to try and stop it.
What are examples of cancer treatment?
chemotherapy
radio therapy
drugs
What is chemotherapy?
Chemotherapy prevents the synthesis of enzymes are required for DNA replication. This stops the cell cycle before the S phase as it cannot take place. If DNA cannot be replicated cells will not be able to divide.Radiotherapy and some chemotherapy drugs can damage DNA, if DNA is damaged then it will not pass the checkpoints in a space. This will force the cells to kill itself (apoptosis)
What does drugs do?
Drugs which prevent spindle fibres from forming will prevent mitosis stage as one will contain double the DNA and one will contain no DNA. This prevents the cell from functioning or dividing again.
