Mutagens: Physical mutagens


Mutagens: Physical mutagens

    Mutagens: Agents which induce mutation are known as mutagens.
    There are two types of mutagen.
     
    Mutagen

    Characteristics

    X- rays

    Electromagnetic radiation; penetrate tissues from a few millimeters to many centimeters first discovered by Roentgen 1895 wavelength varies from 10-11 to 10-7. Highly penetrating they break chromosomes and produce all types of mutation in the nucleotides like addition, deletion, inversion, transition and transversion.

    Gamma rays

    Electromagnetic radiation produced by radioisotopes and nuclear reactors; very penetrating into tissues; sources are Co60 and Ce137 largely used in crop plants

    Neutrons

    A variety exists (fast, slow, thermal); produced in nuclear reactors; uncharged particles; penetrate tissues to many centimeters; source is U235

    Beta particles

    Produced in particle accelerators or from radioisotopes; are electrons; ionize; shallowly penetrating; sources include P32 and C14

    Alpha particles

    Derived from radioisotopes; a helium nucleus capable of heavy ionization; very shallow penetrating

    Protons

    Produced in nuclear reactors and accelerators; derived from hydrogen nucleus penetrate tissues up to several centimeters

    Non ionizing radiations

    Non-ionizing radiation produced from mercury vapor lamps or tubes. They penetrate one or two cell layers eg. Pollen.


Last modified: Monday, 12 March 2012, 10:23 AM