X-rays and ultraviolet light can change the chemical nature of DNA?

Yes, X-rays and ultraviolet light can both cause damage to DNA by altering its chemical structure. This can lead to mutations, which can have a variety of effects on the cell, including cell death or the development of cancer.

X-rays are a type of ionizing radiation, which means that they have enough energy to remove electrons from atoms. This can disrupt the chemical bonds that hold DNA together, causing the DNA to break or become rearranged.

Ultraviolet light is a type of non-ionizing radiation, but it can still damage DNA by causing the formation of thymidine dimers. These are molecules that form when two thymine molecules in the DNA react with each other. Thymidine dimers can block the DNA from being transcribed, which can lead to mutations or cell death.

The amount of damage caused by X-rays and ultraviolet light depends on a number of factors, including the dose of radiation, the wavelength of the radiation, and the type of cell that is exposed.