In 1971,cancer was Thought to Be Caused By

Question

In 1971,cancer was thought to be caused by
A) too little exercise.
B) too much chocolate and other sweets.
C) radiation, viruses, and chemical exposures.
D) oncogenes and tumor suppressor gene mutations.
E) a bacterial infection.

Accepted Answer

In 1971, cancer was thought to be primarily caused by radiation, viruses, and chemical exposures. This was before the discovery of oncogenes and tumor suppressor gene mutations as major contributors to cancer development. Too little exercise and too much consumption of sweets were not considered significant factors in causing cancer, and bacterial infections were not yet known to be linked to certain types of cancer.