When a single cell undergoes a critical genetic mutation in its dna causing cancer it is known as?

Oncogenesis, carcinogenesis

Explanation:

Normally the cancer causing mutation takes place in the DNA of one of the normal cell. The abrupt and continuous cell division leads to increase in number of abnormal cells in the host body. This leads to the development of tumors. This entire process is called as oncogenesis or carcinogenesis.