How does radiation cause mutation?

Hint: Radiation can be described as small (subatomic) kinetic energy particles which are emitted or transmitted through space. One type of radiation has the properties of light, with most of the radiation around us having this quality. For example, x-rays and gamma rays used in medicine. Other radiation has particle-like properties (very small, these particles cannot be seen with a microscope). For eg, alpha rays, beta rays (from radioactive substances) and heavy particle radiation (used in cancer treatment).

Complete answer:
Mutation, modification in the genetic material of a cell of a living organism or virus that is almost permanent and may be transferred to the descendants of a cell or virus. A mutation in the DNA of a body cell of a multicellular organism may be transferred to a descending cell through replication of DNA, resulting in a sector or patch of cells containing abnormal function, such as cancer.

Gene mutations arising from radiation-induced DNA damage were being experimentally developed in many forms of organisms. In general, the frequency of the mutation increases, it is due to the dose of radiation in the low to moderate dose range. With higher doses, though, the rate of mutations induced by a given dose may depend on the rate at which the dose is accumulated, which appears to be lower when the dose is accrued over a long period of time. In human white blood cells, as in mouse sperm cells and oocytes, the rate of radiation-induced mutations is approximately 1 mutation per 100,000 cells per gene locus per Sv. This growth rate is not high enough to identify the nuclear-bomb survivors of Hiroshima and Nagasaki in children using the current technique.The proportionality between both the rate of induced mutations and the dose of radiation has significant health consequences for the human population, because it means that even a little dose of radiation given to a large number of individuals may introduce mutant genes into the population, provided that individuals are well below reproductive age at the time of irradiation.

Note: As long as people live on this planet, we will all be subjected to small levels of radiation. There is an increase in exposure to cosmic radiation for people living at high altitudes. Passengers are exposed to approximately 0.1 mSv (millisievert) of radiation while flying in an aircraft. The atmosphere around earth has a very blocking effect on cosmic radiation.