Back to Blog
Dead cells mutations5/5/2023 ![]() ![]() A mutated form of a gene is called a mutant allele. The most serious changes take place in the functional units of DNA, the genes. The genome is composed of one to several long molecules of DNA, and mutation can occur potentially anywhere on these molecules at any time. Know how a single change in the DNA nucleotide results in mutation and why some mutations are harmful See all videos for this article In general, mutation is the main source of genetic variation, which is the raw material for evolution by natural selection. Because mutations are random changes, they are expected to be mostly deleterious, but some may be beneficial in certain environments. Mutations result either from accidents during the normal chemical transactions of DNA, often during replication, or from exposure to high-energy electromagnetic radiation (e.g., ultraviolet light or X-rays) or particle radiation or to highly reactive chemicals in the environment. Mutations in egg or sperm cells ( germinal mutations) may result in an individual offspring all of whose cells carry the mutation, which often confers some serious malfunction, as in the case of a human genetic disease such as cystic fibrosis. (The genomes of organisms are all composed of DNA, whereas viral genomes can be of DNA or RNA see heredity: The physical basis of heredity.) Mutation in the DNA of a body cell of a multicellular organism ( somatic mutation) may be transmitted to descendant cells by DNA replication and hence result in a sector or patch of cells having abnormal function, an example being cancer. Mutation, an alteration in the genetic material (the genome) of a cell of a living organism or of a virus that is more or less permanent and that can be transmitted to the cell’s or the virus’s descendants. The increased susceptibility of these areas of DNA to mutation is attributed to interactions between mutation-inducing factors, the structure and function of the DNA sequence, and enzymes involved in DNA repair, replication, and modification. Mutation hotspots (or mutational hotspots) are segments of DNA that are especially prone to genetic alteration. SpaceNext50 Britannica presents SpaceNext50, From the race to the Moon to space stewardship, we explore a wide range of subjects that feed our curiosity about space!.Learn about the major environmental problems facing our planet and what can be done about them! Saving Earth Britannica Presents Earth’s To-Do List for the 21st Century.100 Women Britannica celebrates the centennial of the Nineteenth Amendment, highlighting suffragists and history-making politicians.COVID-19 Portal While this global health crisis continues to evolve, it can be useful to look to past pandemics to better understand how to respond today.Student Portal Britannica is the ultimate student resource for key school subjects like history, government, literature, and more.This Time in History In these videos, find out what happened this month (or any month!) in history.#WTFact Videos In #WTFact Britannica shares some of the most bizarre facts we can find.Demystified Videos In Demystified, Britannica has all the answers to your burning questions. ![]() Britannica Classics Check out these retro videos from Encyclopedia Britannica’s archives.Britannica Explains In these videos, Britannica explains a variety of topics and answers frequently asked questions. ![]()
0 Comments
Read More
Leave a Reply. |