Biology XII Notes for Biology Notes

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Cancer is the uncontrolled growth of abnormal cells of body. The abnormal cells are termed cancer cells, malignant cells, or tumor cells. It is also called neoplasm.

Types of Cancer:
There are many of cancers, as follows:

Carcinoma: Cancer that begins in the skin or in tissues that line or cover internal organs.

Sarcoma: Cancer that begins in bone, cartilage, fat, muscle, blood vessels, or other connective or supportive tissue.

Leukemia: Cancer that starts in blood-forming tissue such as the bone marrow and causes large numbers of abnormal blood cells to be produced and enter the blood.

Lymphoma and myeloma: Cancers that begin in the cells of the immune system.

Causes of Cancer:

  • Exposure of body to UV-radiation or X-rays for long.
  • Carcinogens like mustard gas, benzopyerene etc
  • Chewing tobacco and smoking causes lung and oral cancer.
  • Viruses can also cause cancer.

Symptoms of Cancer:
They are as follows:

  • May cause Fever (no clear infectious source, recurrent or constant)
  • There may be Fatigue (not relived by rest)
  • Person claims Weight loss (without trying to lose weight)
  • Pain (usually persistent)
  • Skin changes (coloration, sores that do not heal, white spots in mouth or on tongue, wart changes)
  • Change in bowel or bladder functions
  • Unusual bleeding (mouth, vaginal, and bladder) or discharge
  • There can be Persistent cough or change in voice
  • Lumps or tissue masses are seen

Diagnosis of Cancer:

  • Blood test for blood cancer
  • Bone marrow biopsy
  • CT scans and MRI
  • Analysis of molecular changes of cancerous cells

Treatment of Cancer:

  • Medicines like ABC etc
  • Interferon medicines

Prevention’s of Cancer:

  • Avoiding smoking tobacco.
  • Avoiding excess sunlight (by decreasing exposure or applying sunscreen) and many of the chemicals and toxins is an excellent way to avoid cancers.
  • Avoiding contact with certain viruses and other pathogens also is likely to prevent some cancers.
  • People who have to work close to cancer-causing agents (chemical workers,
  • X-ray technicians, ionizing radiation researchers) should follow all safety precautions and minimize any exposure to such compounds.
  • There are two vaccines currently approved by the U.S. Food and Drug Administration (FDA) to prevent specific types of cancer. Vaccines against the hepatitis B virus, which is considered a cause of some liver cancers, and vaccines against human papillomavirus types 16 and 18, which, according to the NCI, are responsible for about 70% of cervical cancer.

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