Scientists Say: Mutation

Mutation (noun, “Mew-TAY-shun”)

A change that occurs in an organism’s DNA, those long chemical chains that carry instructions telling cells what molecules to make. Mutations can occur on a gene — a segment of the DNA that holds instructions — or in areas that do not have instructions. When a gene mutates, it may function in new ways. Others mutations may turn a gene’s sensible instructions into nonsense. Some mutant genes can make an organism’s life easier. Others can make it harder. And still others may make no difference at all. Mutations can occur naturally or be triggered by outside factors such as pollution and radiation.

In a sentence

A mutation in a tiny loop of DNA has given bacteria the ability to resist the last-ditch drugs we use to kill them.

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Power Words

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DNA  (short for deoxyribonucleic acid) A long, double-stranded and spiral-shaped molecule inside most living cells that carries genetic instructions. In all living things, from plants and animals to microbes, these instructions tell cells which molecules to make.

gene   (adj. genetic) A segment of DNA that codes, or holds instructions, for producing a protein. Offspring inherit genes from their parents. Genes influence how an organism looks and behaves.

mutation  Some change that occurs to a gene in an organism’s DNA. Some mutations occur naturally. Others can be triggered by outside factors, such as pollution, radiation, medicines or something in the diet. A gene with this change is referred to as a mutant.

radiation   (in physics) One of the three major ways that energy is transferred. (The other two are conduction and convection.) In radiation, electromagnetic waves carry energy from one place to another. Unlike conduction and convection, which need material to help transfer the energy, radiation can transfer energy across empty space.