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The international pictogram for chemicals that are sensitising, mutagenic, carcinogenic or toxic to reproduction. In genetics, a mutagen is a physical or chemical agent that permanently changes genetic material, usually DNA, in an organism and thus increases the frequency of mutations above the natural background level.
In animals or plants, most mutations are neutral, ... Malaria resistance: An example of a harmful mutation is sickle-cell disease, ...
Comfrey is an example of a plant species that contains fourteen different PAs. The active metabolites interact with DNA to cause DNA damage, mutation induction, and cancer development in liver endothelial cells and hepatocytes. The researchers discovered in the end that the "comfrey is mutagenic in liver, and PA contained in comfrey appear to ...
Genetic pollution is a term for uncontrolled [1] [2] gene flow into wild populations. It is defined as "the dispersal of contaminated altered genes from genetically engineered organisms to natural organisms, esp. by cross-pollination", [3] but has come to be used in some broader ways.
DNA may be modified, either naturally or artificially, by a number of physical, chemical and biological agents, resulting in mutations. Hermann Muller found that "high temperatures" have the ability to mutate genes in the early 1920s, [2] and in 1927, demonstrated a causal link to mutation upon experimenting with an x-ray machine, noting phylogenetic changes when irradiating fruit flies with ...
They come in all shapes and sizes. Some walk, some slither, some fly and some swim. Humans are blessed to share the planet with just over 2.1 million recognized species of animals. And scientists ...
Random mutations are the ultimate source of genetic variation. Mutations are likely to be rare, and most mutations are neutral or deleterious, but in some instances, the new alleles can be favored by natural selection. Polyploidy is an example of chromosomal mutation. Polyploidy is a condition wherein organisms have three or more sets of ...
Incidental, or natural mutations occur through errors during replication and repair, either spontaneously or due to environmental stressors. Intentional modifications are done in a laboratory for various purposes, developing hardier seeds and plants, and increasingly to treat human disease. The use of gene editing technology remains controversial.