X-rays and gamma rays are types of Ionizing radiation. Ionizing radiation of all kinds when it passes into or through some kind of material will undergocollisions with the atoms. These collisions create ions in the material. In living tissue the ions produced in this way will cause harm to the cells.
Ionizing radiation absorbed by human tissue has enough energy to remove electrons from the atoms that make up molecules of the tissue. When the electron that was shared by the two atoms to form a molecular bond is dislodged by ionizing radiation, the bond is broken and thus, the molecule falls apart. This is a basic model for understanding radiation damage. When ionizing radiation interacts with cells, it may or may not strike a critical part of the cell. We consider the chromosomes to be the most critical part of the cell since they contain the genetic information and instructions required for the cell to perform its function and to make copies of itself for reproduction purposes. Also, there are very effective repair mechanisms at work constantly which repair cellular damage - including chromosome damage.
The following are possible effects of radiation on cells:
1.)Cells are undamaged by the dose