Search results
Results From The WOW.Com Content Network
These types of mutations are usually prompted by environmental causes, such as ultraviolet radiation or any exposure to certain harmful chemicals, and can cause diseases including cancer. [91] With plants, some somatic mutations can be propagated without the need for seed production, for example, by grafting and stem cuttings.
It can also be achieved experimentally using laboratory procedures. A mutagen is a mutation-causing agent, be it chemical or physical, which results in an increased rate of mutations in an organism's genetic code. In nature mutagenesis can lead to cancer and various heritable diseases, and it is also a driving force of evolution.
In such methods, cells or organisms are exposed to mutagens such as UV radiation or mutagenic chemicals, and mutants with desired characteristics are then selected. Hermann Muller discovered in 1927 that X-rays can cause genetic mutations in fruit flies, [6] and went on to use the mutants he created for his studies in genetics. [7]
Radiolysis of intracellular water by ionizing radiation creates peroxides, which are relatively stable precursors to hydroxyl radicals. 60%–70% of cellular DNA damage is caused by hydroxyl radicals, [3] yet hydroxyl radicals are so reactive that they can only diffuse one or two molecular diameters before reacting with cellular components.
Radiation hormesis is the conjecture that a low level of ionizing radiation (i.e., near the level of Earth's natural background radiation) helps "immunize" cells against DNA damage from other causes (such as free radicals or larger doses of ionizing radiation), and decreases the risk of cancer. The theory proposes that such low levels activate ...
Exposure to radiation causes chemical changes in gases. The least susceptible to damage are noble gases, where the major concern is the nuclear transmutation with follow-up chemical reactions of the nuclear reaction products. High-intensity ionizing radiation in air can produce a visible ionized air glow of telltale
Deficient expression of DNA repair proteins due to an inherited mutation can cause increased risk of cancer. Individuals with an inherited impairment in any of 34 DNA repair genes (see article DNA repair-deficiency disorder ) have an increased risk of cancer, with some defects causing up to a 100% lifetime chance of cancer (e.g. p53 mutations ...
Mutation breeding, sometimes referred to as "variation breeding", is the process of exposing seeds to chemicals, radiation, or enzymes [1] [2] in order to generate mutants with desirable traits to be bred with other cultivars. Plants created using mutagenesis are sometimes called mutagenic plants or mutagenic seeds.