Final answer:
When an x-ray or gamma ray photon is absorbed in a tumor, it can lead to cell death by carrying enough energy to ionize molecules and damage the cell's DNA, which is the principle used in radiation therapy.
Step-by-step explanation:
When an x-ray (or gamma ray) photon is absorbed in a tumor, it may cause the tumor cell to die because the photon carries enough energy to damage molecules and cause chemical injury to the cell.
This is because these types of radiation have very high energy that can ionize atoms and molecules, leading to damage in the DNA and other vital components of the cell. Consequently, this damage can result in cell death, which is a fundamental principle behind radiation therapy for cancer treatment where targeted radiation is used to destroy tumor cells.