What is cancer? How is a cancer cell different from a normal cell? How do normal cells attain cancerous nature?

(N/A) Cancer is defined as the abnormal and uncontrolled division of cells.
The differences between cancer cells and normal cells are as follows:

Cancer Cells	Normal Cells
$(1)$ Cancer cells divide in an uncontrolled manner.	$(1)$ Normal cells divide in a controlled manner.
$(2)$ These cells do not show contact inhibition.	$(2)$ These cells show contact inhibition.
$(3)$ Life span is indefinite.	$(3)$ Life span is definite.

- In our body,the growth and differentiation of cells are highly controlled and regulated.
- Normal cells exhibit a property called contact inhibition,where contact with other cells inhibits their uncontrolled growth and division.
- Cancerous cells lose this property of contact inhibition,leading to continuous,uncontrolled division,which results in masses of cells known as tumors.
- The transformation of normal cells into cancerous cells is induced by physical,chemical,or biological agents known as carcinogens.