Chemical mutagen is a mutation agent which is in the form of chemical substance, It can mimic nitrogen base in normal DNA' but they cannot couple during DNA replication. Moreover, chemical mutagen has an ability to insert between nitrogen bases and disturb DNA replication' The examples of chemical mutagen can be seen in Types And Characteristics Of Mutagen .
Physical mutagen is a mutation agent which is in the form of physical substances, such as short wave (ultraviolet and radiation ray such as alpha, beta, and gamma). Some physical mutagens can cause ionization while some others cannot.
Ionization usually occurs because the radiation source has very large energy, For example, radiation from radioactive substances (uranium, radium, cobalt), X-ray, and cosmic ray, If DNA molecules are hit by the radiation, the DNA chain will loose. In consequence, the DNA chain cannot function in protein synthesis.
Ultraviolet ray generally do not cause ionization, However, the energy from ultravlolet ray will be absorbed by purine and ppimidine so that the atom becomes more reactive (the electron undergoes exitation). Consequently, DNA double-helix becomes in disorder and inhibits replication, One of the effects caused by ultraviolet ray is skin cancer.
When we watch black and white television in an hour, we will be hit by I mrem radiation every hour, If we watch colored television, the effect becomes doubled, If we are diagnosed by X-ray, we will be hit by 150 mrem radiation, and every time we have our teeth portrayed, we get hit by 20 mrem radiation, Note that I to 2 dosage of mrem is already able to induce mutation.
Biological mutagen is a mutation agent in the from of virus or bacteria Which can include mutation in every living organisms
When cell divides, virus will change the genetic material (DNA) Composition of the attacked cell I order to damage the cell and tissues Toxin produced by bacteria can also cause disorder or damage on genetic Material or certain cell and tissues. Hepatitis, chickenpox, measles, yellow Fever, or food poisoning (botulism) may begin from genetical material change induced either by virus or bacteria
Source: Human Biology, 2004