Human Health and Disease — BIOLOGY STD 12 Science — Question

Cell growth and differentiation in our body is highly controlled and regulated. These regulatory mechanisms are broken down in cancer cells. Normal cells exhibit a property called contact inhibition and due to this property their contact with other cells inhibits their uncontrolled growth. It seems that this property has been lost in cancer cells. As a result, cancer cells continue to divide and form a mass of cells called a tumor. There are two types of tumors-benign (benign) and malignant (malignant). Small tumors generally remain limited to their original location. On the other hand, a malignant tumor is a mass of proliferating cells called neoplastic cells. They grow very quickly and attack and damage nearby normal tissues.