what are the four phases of the cell life cycle
- G0 performing regular functions but not preparing for cell division
- G1 (first growth phase) produces new proteins, grows and carries out normal tasks
- S (Synthesis phase) DNA replication
- G2 (second growth phase) growth and preparation for m
- m (mitosis) Prophase, Metaphase, Anaphase, Telophase
what are the phases of mitosis
Interphase, Prophase, Metaphase, Anaphase, Telophase
what occurs during interphase
Period between nuclear divisions, DNA in nucleus doubles
what occurs during prophase
(Pro=first)
chromatin coils to become chromosomes, nuclear membrane breaks down, spindle fibres grow from centrioles, centrioles migrate to poles
what occurs during metaphase
(meta=middle)
Chromosomes line up in middle, some spindles attach to centromeres
what occurs during anaphase
(ana=away)
spindle fibres pull new chromosomes to poles. each pol now has identical set of genes
what occurs during telophase
(Tel=two)
chromosomes gather at pole, 2 nuclear membrane appear. cytokinesis also occurs
what is cell differentiation
process by which cells become specialised. As mitosis occurs, different genes become activated, meaning cells become specific for certain tasks
what are stem cells
cells that undergo differentiation, aren’t specialised
what are the two types of tumours
- Maligent (when tumour cells are able to spread to other parts of the body)
- Benign (the tumour does not spread to other parts)
what are carcinogens (give 5 examples)
environmental factors that can trigger tumours (UV radiation, xrays, Ionising radiation, viruses, chemical carcinogens)
what causes a tumour
uncontrolled division of cells
how has the incidence of cancer been reduced in Australia
Education - public awareness of dangers of carcinogens (slip,slap,slop)
legislation - passing laws to control exposure of carcinogens
what is cervical cancer and how is it detected
- caused by HPV which is transmitted via genital contact
- detected by pap test which examines cervical cells for abnormalities
how is breast cancer detected
- mammography (xray of the breast which produces a mammogram) tumours detected on X ray pictures
what is bowel cancer and how is it detected
- Malignant tumour that develops in the large intestine
- detected using a FOBT which tests for blood in faeces caused by polyps which can lead to cancer
how is prostate cancer detected
- DRE test (bum gets fingered)
- PSA test which checks the blood for increased levels of a protein produced by the prostate
- biopsy which involves the use of a needle to collect a small sample tissue that can be checked for cancer celss
