Cancer

A mutation in the genes that cause cell division to grow out of control

UV rays - ionising radiation Carcinogenic chemicals - Smoking

Malignant - Grows fast and will invade other parts of body Benign - Grows slowly and kept in one place and doesn’t invade othet parts of tissue

Chemotherapy Radiotherapy Drugs

Prevents synthesis of enzymes required for DNA replication stop the cell cycle before the S phase . DNA cannot be replicated so cell won’t divide

Damages DNA so the cell will not pass the check points in the S phase . Forces the cell to kill itself (Apoptosis)

Prevent spindle fibres from forming which will prevent mitosis as one cell will contain double the DNA and one cell will have none making them both unsuitable for division