|Class 12 Biology Human Health Disease||Cancer|
Cancer is the uncontrolled cell division leading to the formation of a mass of cells called as a tumor.
Contact inhibition is the property of normal cells by virtue of which contact with other cells inhibits their uncontrolled growth.
Cancer cells lost the property of contact inhibition and as a result of this, cancerous cells continue to divide giving rise to masses of cells called tumors.
Tumors are of two types: benign and malignant.
Benign tumors normally remain confined to their original location and do not spread to other parts of the body.
The malignant tumors are a mass of proliferating cells called neoplastic or tumor cells.
Malignant tumors grow very rapidly and invade and ultimately damage surrounding tissues.
The property by which cancer cells moves to distant places from their origin by blood and invade the normal cells and make them cancerous is called as metastasis
Causes of cancer-
1. Cancer causing viruses are called oncogenic viruses have genes called viral oncogenes.
2. Cellular oncogenes or proto-oncogenes in normal cells, when get activated lead to oncogenic transformation of normal cells.
Fig. oncogenic virus
Detection of cancer-
Treatment of cancer-
Fig. cancer cells