Answer to Question #85297 in Genetics for michelle

Question

explain how two examples of physical mutagens exhurt thier mutagenic effects

Answer 1

Ultraviolet mutagenesis is called mutagenesis caused by irradiating a DNA molecule with ultraviolet light. After irradiation with ultraviolet light, photoproducts are formed in the DNA molecule. In most cases, these are cyclobutane pyrimidine dimers. Photodimers are usually removed during DNA repair. If not all photodimers are removed, then DNA synthesis is also possible on a matrix containing photodimers as a result of error-prone or SOS replication. Mutations result from the formation of non-complementary DNA base pairs due to sporadic errors in DNA polymerases.

Particles formed during the radioactive decay of a substance also have a mutagenic effect. Electromagnetic radiation or elementary particles passing through a substance transfer their energy to atoms that are transformed into positively charged ions. The released electrons for the second time cause the formation of pairs of ions until their energy is exhausted. DNA damage occurs both as a result of the direct entry of an elementary particle into the molecule, and as a result of the secondary action of the secondary ions (i.e., reactive oxygen species). The process is associated with direct DNA damage, inappropriate replication, and formation of the mutation.